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SANTA CLARA VALLEY WATER DISTRICT 


THIRD ADDENDUM TO THE 
FINAL ENVIRONMENTAL IMPACT REPORT 
FOR THE UPPER GUADALUPE RIVER 
FLOOD PROTECTION PROJECT 


EVALUATION OF MITIGATION IMPROVEMENTS 
AND PROJECT DESIGN CHANGES FOR REACH 12 

PROJECT NO. 26154003 


Prepared by 

James Manitakos 
Environmental Planner II 

Under the direction of 

Jennifer Castillo 

Environmental Planning Unit Manager 


Santa Clara Valley Water District 
5750 Almaden Expressway 
San Jose, CA 95118 


JULY 2014 



TABLE OF CONTENTS 


1. BACKGROUND 3 

2. CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) 

CONSIDERATIONS 4 

3. DESCRIPTION OF PROPOSED ACTION 6 

4. IMPACT ANALYSIS 9 

5. CONCLUSION REGARDING APPROPRIATE LEVEL OF REVIEW 13 

6. BIBLIOPGRAPHY 13 

TABLES 

Table 1: Current Reach 12 Project compared to 1999 EIR Preferred Project 4 

Table 2: Protected Species with Modeled Habitat Distribution that includes 

Reach 12 Project Area 11 

FIGURES 

Figure 1: Regional Location of the Upper Guadalupe River Flood Protection 

Project 7 

Figure 2: Map of Upper Guadalupe River Reach 12 8 

APPENDICES 

A: U.S Army Corps of Engineers Supplemental Environmental Assessment and 
Final Finding of No Significant Impact 

B: Site-Specific Biological Evaluation, Potential Occurrence of Four Protected 
Species at Upper Guadalupe River Reach 12 


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1. BACKGROUND 


The Santa Clara Valley Water District (District) is partnering with the U.S. Army Corps of 
Engineers San Francisco District (Corps) to implement the Upper Guadalupe River Flood 
Protection Project (UGRFPP), formerly known as the Upper Guadalupe River Flood Control 
Project. In 1999, the two agencies prepared a joint Environmental Impact Report and 
Environmental Impact Statement (EIR/EIS) analyzing environmental consequences that would 
result from proposed improvements to Reaches 6 through 12 of Guadalupe River. For that 
EIR/EIS, the Corps was the National Environmental Policy Act (NEPA) lead agency and the 
District was the California Environmental Quality Act lead agency. The preferred project 
analyzed in the EIR/EIS included the following proposed improvements at Reach 12: 

1. Widen the river channel between Chynoweth Avenue and Branham Lane 

2. Construct a depressed maintenance access road on east bank 

3. Excavate the west bank to create a depressed vegetated bench between Chynoweth 
Avenue and Blossom Hill Road 

4. Construct raised levees on east and west banks 

5. Create an 18-ft wide floodway on east bank 

6. Construct channel access ramps on east bank 

7. Construct a Chynoweth Avenue bridge over the river 

8. Create off-channel percolation pond and associated wetlands on west bank 

9. Create riparian, wetland, and open water habitats 

10. Maintain planted vegetation and reach improvements 

The EIR/EIS found that implementation of the preferred project would result in unavoidable 
adverse effects in a number of topic areas, but that all environmental effects could be mitigated 
to a less than significant level. On August 15, 2001, the District’s Board of directors approved 
Resolution 2001-51, which 

• certified the 1999 UGRFPP EIR 

• adopted a mitigation monitoring and reporting plan 

• found that implementation of the preferred project would not result in significant adverse 
environmental impacts after application of mitigation measures, and 

• rejected alternatives to the preferred project. 

The District and Corps are now proposing improvements to Reach 12 that differ from the 
preferred project that were analyzed in the 1999 EIR/EIS. The changes are designed to improve 
the quality and amount of in-stream, riparian, and upland habitat at this reach. 

In compliance with requirements of the NEPA, the Corps prepared a Supplemental 
Environmental Assessment (SEA) analyzing the environmental consequences of the currently 
proposed Reach 12 improvements (U.S. Army Corps of Engineers San Francisco District, 

2014). The Corps determined that the proposed action for Reach 12 would not have a 
significant effect on the environment and prepared a Finding of No Significant Impact (FONSI) 
for the Reach 12 improvements. Section 2 of the Corps SEA, attached as Appendix A to this 
EIR Addendum No. 3, describes the proposed Reach 12 improvements in detail. As described 
in more detail below, CEQA allows a lead agency to use a FONSI prepared by a federal agency 
if certain conditions are met. This Addendum No. 3* incorporates the analysis and findings in 
the Corps SEA and Final FONSI analyzes other issues required by CEQA and not otherwise 
covered in the Corps SEA and Final FONSI. 


*Addendums No. 1 (June 2006) and No. 2 (March 2009) analyzed proposed improvements to Reach 6 of the UGRFPP which 
differed from the proposed Reach 6 improvements analyzed in the 1999 EIR. 

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2. CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) 
CONSIDERATIONS 


Once the CEQA review for a project has been conducted and the lead agency has adopted its 
Findings with respect to impacts and proposed mitigations, these decisions need no additional 
review per CEQA. The lead agency’s role has been fulfilled unless there are changes to the 
project and further actions are necessary that involve the exercise of the lead agency’s 
discretion regarding the project. 

As the CEQA lead agency for Reach 12 channel improvements, the District re-evaluated the 
1999 EIR and Board Resolution in light of changes in the Reach 12 project design, and 
independently reviewed the Corps SEA and Final FONSI. Table 1, below, compares the 
currently proposed Reach 12 improvements to the project elements analyzed in the 1999 EIR. 
As indicated below, the currently proposed project does not include several elements of the 
1999 project and incorporates several new elements not included in the 1999 project. 


Table 1: Current Reach 12 Project compared to 1999 EIR Preferred Project 

Element 

Part of 1999 EIR 
Preferred 

Project? 

Part of 2014 

Project? 

Widen the river channel between Chynoweth 

Avenue and Branham Lane 

yes 

no 

Construct a depressed maintenance access 
road on east bank 

yes 

no 

Excavate the west bank to create a 
depressed vegetated bench between 

Chynoweth Avenue and Blossom Hill Road 

yes 

no 

Construct raised levees on east and west 
banks 

yes 

no 

Create an 18-ft wide floodway on east bank 

yes 

no 

Construct a Chynoweth Avenue bridge 
crossing the river 

yes 

no 

Create an off-channel percolation pond and 
associated wetlands on west bank 

yes 

no 

Remove non-native and invasive vegetation 

no 

yes (2.3)* 

Create flood bench 

no 

yes (2.4.1)* 

Augment in-channel gravel 

no 

yes (2.4.2)* 

Install in-channel structures (debris jams, 
root wads, stream barbs, toe structures) to 
improve fish habitat 

no 

yes (2.4.3)* 


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Table 1: Current Reach 12 Project compared to 1999 EIR Preferred Project 

Raise berms between river and adjacent 
percolation ponds 

no 

yes (2.5)* 

Construct channel access ramps on east 
bank 

yes 

yes (2.6)* 

Construct maintenance access roads at top 
of east and west banks 

no 

yes (2.6)* 

Create riparian, wetland, and open water 
habitats 

yes 

yes (2.7)* 

Plant native vegetation 

yes 

Yes (2.8)* 

Install fencing 

no 

yes (2.9)* 

Maintain vegetated plants and reach 
improvements 

yes 

yes (2.10)* 

‘Subsection of Corps SEA describing this project element is given in parentheses 


CEQA Guidelines §15164 state “The lead agency or responsible agency shall prepare an 
addendum to a previously certified EIR if some changes or additions are necessary but none of 
the conditions described in Section 15162 calling for preparation of the a subsequent EIR have 
occurred.” The current Reach 12 project represents a change to the project analyzed in the 
1999 EIR, but the changes would not result in new significant environmental impacts or an 
increase in the severity of previously identified significant effects, as documented in the impact 
analysis contained in Corps SEA and supplemented by Section 4 below. Additionally, the Reach 
12 project includes all feasible mitigation measures that would reduce environmental impacts of 
the project, including new measures not previously listed in the 1999 EIR. No alternatives to the 
proposed project have been identified since preparation of the 1999 EIR that would substantially 
reduce one or more significant effects on the environment. The current Reach 12 project would 
not involve any of the CEQA §15162 conditions that would require a Subsequent EIR; thus 
preparation of an EIR Addendum is warranted. 

As described above, the Corps prepared a SEA and Final FONSI for the proposed Reach 12 
improvements (U.S. Army Corps of Engineers, 2014). These documents analyze the 
environmental consequences of the currently proposed improvements, and find that the 
amended project would not result in significant effects to the environment. CEQA Guidelines 
§15221 states: 

(a) When a project will require compliance with both CEQA and NEPA, state or local 
agencies should use the EIS or FONSI rather than preparing an EIR or Negative 
declaration if the following two conditions occur: 

(1) An EIS or FONSI will be prepared before an EIR or Negative Declaration 
would otherwise be completed for the project; and 

(2) The EIS or FONSI complies with the provisions of the guidelines. 

(b) Because NEPA does not require separate discussion of mitigation measures or 
growth inducing impacts, these points of analysis will need to be added, 
supplemented, or identified before the EIS can be used as an EIR. 

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The District has independently reviewed the Corps SEA and Final FONSI and determined that 
they comply with the provisions of the CEQA Guidelines and include detailed discussion of 
mitigation measures. This EIR Addendum incorporates the Corps SEA’s analysis and contains 
the additional analysis required by the CEQA guidelines. 

3. DESCRIPTION OF PROPOSED ACTION 

The Reach 12 improvements are designed to increase the amount and quality of aquatic and 
riparian habitat in Reach 12 and to create a more sustainable geomorphic channel. The Reach 
12 improvements would also provide mitigation for impacts to riparian forest and shaded riverine 
aquatic cover resulting from the overall UGRFPP. Reach 12 is within the City of San Jose and 
extends from Branham Lane (downstream project limit) to Blossom Hill Road (upstream project 
limit). Figure 1 shows the river location and Figure 2 contains a map of Reach 12. Reach 12 has 
existing capacity to convey the 1% annual probability flow, which is estimated at 11,400 cubic 
feet per second (cfs). However, minor modifications to the channel are required to prevent flood 
waters from affecting adjacent percolation ponds and to improve access to the channel for 
maintenance purposes. The Corps proposes to perform the actions listed below: 

• selectively remove non-native and invasive vegetation, 

• temporarily dewater sections of the river reach during the 2014 and 2015 dry seasons to 
facilitate in-channel construction, 

• excavate and regrade portions of the existing river channel to create in-channel 
vegetated benches and enhance habitat, 

• raise about 2,800 linear feet (LF) of existing berms to the east and west of the river that 
separate the creek from nearby percolation ponds, 

• construct about 9,100 LF of maintenance access roads surfaced with compacted 
aggregate on the east and west banks of the river, 

• construct 3 ramps accessing the low-flow channel for maintenance use, 

• install a number of in-stream structures (debris jams, stream barbs, root wads, and 
undercut banks) to enhance fish habitat, 

• place about 6,000 cubic yards (cy) of gravel at four locations in the low-flow channel to 
create a more natural channel form and enhance fish habitat, 

• plant large numbers of native plants in six planting zones (in-stream, streamside, lower 
and upper floodplain, upland, hydroseeding) to create shaded riverine aquatic, riparian, 
and upland habitat, 

• use a water truck and hose to water the new plants by hand, 

• install about 3,000 LF new chain-link fence on the west bank for security reasons, 

• replace and repave sections of the existing Guadalupe River pedestrian/bicycle trail 
which will be disturbed during project construction, 

• actively manage the new plants and monitor their success, and 

• periodically report results of monitoring efforts to regulatory agencies. 

The Corps plans to construct the improvements to Reach 12 during calendar years 2014 and 
2015. The Corps will be responsible for construction of the proposed reach improvements 
(including hiring and overseeing contractors) and environmental monitoring and reporting 
required by permits. The District will provide the Corps with authorization for entry for 
construction on District owned lands in Reach 12. 


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Figure 1: Regional Location of the Upper Guadalupe River Flood Protection Project 


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Figure 2: Map of Upper Guadalupe River Reach 12 


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As described in Section 2.2 of the Corps SEA, construction activities within the channel will 
occur during the dry season. As required by regulatory approvals issued by the National Marine 
Fisheries Service (NMFS) and the San Francisco Bay Regional Water Quality Control Board 
(RWQCB), construction activities within the river channel will occur only when the stream has 
been temporarily dewatered. The NMFS Supplemental Biological Opinion for the UGRFPP, 
which contains an Incidental Take Statement for the threatened steelhead (Oncorhynchus 
mykiss), and the RWQCB Order R2-2003-0115, which provides waste discharge requirements 
and water quality certification for the UGRFPP, require that dewatering occur only between 
June 1 and October 15. If monitoring activities find no presence of juvenile steelhead and river 
water temperature exceeding 64° F for 3 consecutive days, the Corps may request permission 
to dewater Reach 12 and start construction as early as May 1. The RWQCB’s Executive Officer 
must approve the request for an early start before in-water construction may begin (RWQCB, 
San Francisco Bay Region, 2003; NMFS, 2005). Hydroseeding will occur in the fall after 
construction activities on the channel segment(s) that have been completed. Installation of 
plants will occur in the rainy season following the completion of construction. The Corps will 
monitor the effectiveness of the mitigation measures at creating fish and wildlife habitat and 
report results annually to the RWQCB. As required by the EIR/EIS Mitigation Monitoring and 
Reporting Program adopted by SCVWD Board of Directors and the RWQCB permit, monitoring 
and reporting will continue for a minimum of 5 years after construction is concluded (SCVWD 
and U.S. Army Corps of Engineers, 1999; California RWQCB, San Francisco Bay Region, 

2003). 

4. IMPACT ANALYSIS 

A. SEA AND FINAL FONSI 

The U.S. Army Corps of Engineers San Francisco District published a SEA and FONSI 
analyzing the environmental consequences of the currently proposed Reach 12 project. The 
Corps issued the SEA and Draft FONSI for public review and comment on May 9, 2014, and the 
review period closed on June 9, 2014. The Corps document analyzes potential impacts in the 
following topic areas and identifies measures to avoid, minimize, and mitigate for environmental 
effects. 


• Flood risk management 

• Flows, currents, and circulation 

• Ground Water ( aquifer recharge) 

• Soil quality 

• Water quality 

• Biological environment 

• Air quality 

• Historic and cultural resources 

• Noise 

• Recreation 

• Transportation and traffic 

• Land Use 

• Aesthetics 

• Public utilities, facilities, and services 

• Public health and safety 

• Cumulative impacts 

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The Corps analysis indicates that the impacts of the currently proposed Reach 12 
improvements on the above resources would not be significant and that the proposed 
avoidance, minimization, and mitigation measures would further reduce the intensity of adverse 
impacts to the environment. The District found this analysis to be accurate and adequate for 
purpose of complying with CEQA. The analysis below supplements the Corps SEA and Final 
FONSI and discusses topics that are required by CEQA but not required by NEPA and thus not 
included in the Corps documents. These topics include impacts on state protected wildlife 
species and growth-inducing effects. 


B. VALLEY HABITAT PLAN, CORPS EA, AND SITE-SPECIFIC BIOLOGICAL 
EVALUATION 

This section supplements the analysis of potential impacts to biological resources contained in 
the Corps SEA, which analyzed impacts to Federal-protected species, but not State-protected 
species that lack Federal protection. The District is one of six co-permittees of the Santa Clara 
Valley Habitat Plan, which was a Habitat Conservation Plan prepared under Section 10 of the 
federal Endangered Species Act (ESA) and a Natural Communities Conservation Plan prepared 
under the Natural Community Conservation Planning Act (California Fish and Game Code § 
2800 et seq.). The Corps is not a co-permittee. The Plan provides ESA approval to covered 
activities undertaken by the District and other co-permittees and requires the co-permittees to 
submit application packages to the Valley Habitat Agency, pay fees in proportion to the amount 
and types of habitat affected by the covered activity, and implement avoidance and mitigation 
measures. The Plan exempts a number of projects and activities from coverage, including 
“Corps led projects.” The plan states: 

Projects that are led by the Corps (i.e. the Corps has control over design, 
avoidance, and minimization measures and mitigation) including levee and flood 
protection projects, are not covered activities under this plan. 

The proposed Reach 12 project is led by the Corps and thus is exempt from requirements of the 
Valley Habitat Plan. However, the Plan does include a comprehensive overview of potential 
habitat for Federal and State protected species in the Plan area and Reach 12 is within the area 
covered by the plan. Therefore, the Plan provides a useful starting point for analysis of effects 
on protected species. The Plan maps habitat distribution for 15 species protected under federal 
law, state law, or both federal and state law. The Plan modeling is performed at a regional level 
based on species requirements. As stated in the Plan: 

Habitat distribution models have been developed on a regional scale using regional 
data. The models are intended for use in regional planning and do not necessarily 
provide accurate site-specific species information. For project planning, model 
results must always be field-verified. 

Table 2 lists the species with predicted habitat distribution that includes the Reach 12 project 
area (County of Santa Clara et. al., 2012). Using this list as a starting point, the District prepared 
a Site-specific Biological Evaluation to determine the potential for the four species to occur at 
Reach 12 (see Appendix A). The Site-specific Biological Evaluation includes a review of prior 
observations and scientific reports, search of the database, and a field verification of Reach 12 
conditions by a District wildlife biologist. 


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TABLE 2: Protected Species with Modeled Habitat Distribution that includes 

Reach 12 Project Area* 

Common 

Name 

Scientific 

Name 

Status 

Potential 

Habitat 

California 

Rana aurora 

Federal threatened; 

Breeding 

red-legged 

frog 

draytonii 

California Species of 

Special Concern 
(SSC) 

habitat 

Tri-colored 

Agelaius 

Federal MBTA 

Primary 

blackbird 

tricolor 

California SSC 

habitat 

Foothill 
yellow¬ 
legged frog 

Rana boylii 

California SSC 

Secondary 

habitat 

Western 
pond turtle 

Actinemys 

marmorata 

(AKA 

Clemmys 

marmorata) 

California SSC 

Primary 

habitat 

*Habitat modeling contained in Final Santa Clara Valley Habitat Plan, Volume 4, Appendix D: 

Species Accounts 


The Corps SEA analyzed the potential for occurrence in the project area of the federally 
protected species, including the California red-legged frog. Although the Guadalupe River is 
potential habitat for the California red-legged frog, this species has long been absent from 
urbanized parts of the valley floor. Non-native bullfrogs and predatory fish present in Reach 12 
feed on the California red-legged frog, rendering this reach unsuitable for the California red- 
legged frog. The Corps SEA concludes that there is no potential for this species to occur in the 
project area (U.S. Army Corps of Engineers San Francisco District, 2014) and this finding is 
confirmed by the Site-specific Biological Evaluation. No impacts to the California red-legged frog 
are expected. 

The tri-colored blackbird is protected by the Federal Migratory Bird Treaty Act (MBTA). The Site- 
specific Biological Evaluation finds that the tricolored blackbird is very unlikely to nest in the 
project area. Nonetheless, the Corps will implement avoidance and mitigation measure BIO-5 to 
prevent impacts to the tricolored blackbird and other protected bird species. BIO-5 includes pre¬ 
construction surveys for the presence of bird nests, establishment of a buffer zone around nests 
of protected bird species, and periodic monitoring during construction to ensure the nests and 
occupants are not disturbed or harmed. This measure will prevent adverse effects on the 
tricolored blackbird (U.S. Army Corps of Engineers San Francisco District, 2014). Application of 
measure BIO-5 will reduce the level of potential impact to the Tri-colored blackbird to less than 
significant. 

The foothill yellow-legged frog and the Western pond turtle are California SSCs, but are not 
federally protected. Although the Valley Habitat Plan models the Upper Guadalupe River as 

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potential secondary habitat for the foothill yellow -legged frog, the level of urbanization and 
presence of predatory bullfrogs and fish make it unlikely that Foothill yellow-legged frog would 
occur at Reach 12. The Site-specific Biological Evaluation concludes that foothill yellow-legged 
frog is very unlikely to occur at Reach 12 and no impacts on this species are expected. 

The Santa Clara Valley Habitat Plan models Reach 12 as potential primary habitat for the 
Western pond turtle. The Site-specific Biological Evaluation concludes that the Western pond 
turtle could be present at Reach 12, but that suitable breeding habitat is lacking. To prevent 
impacts to this species, the Corps SEA includes biological avoidance and minimization measure 
BIO-6, which includes pre-construction surveys for the Western pond turtle, relocation of turtles 
out of the construction area by a qualified biologist if necessary, and installation of exclusion 
fending to prevent turtles from re-entering the construction area. The Corps will implement 
avoidance and minimization measure BIO-6 (DeJager, 2014). With application of this measure, 
potential impacts to the Western pond turtle will be less than significant. Overall, impacts to all 
biological resources, including protected species and habitat, will be less than significant. 

C. GROWTH-INDUCING EFFECTS 

CEQA Guidelines §15126.2(c) require analysis of potential growth-inducing effects of the 
project. The proposed Reach 12 improvements would result in environmental enhancement of 
this reach, which is surrounded by urban development. During construction, the project would 
result in about $10 million of construction expenditures, which would provide a minor boost to 
the local economy during the two-year implementation period. The U.S. Census Bureau 
estimates the year 2012 gross domestic product of the City of San Jose at $33.2 billion .Thus 
project construction expenditures would represent a negligible 0.03% of local economic activity. 
Even including the multiplier effect, project expenditures would not induce a significant increase 
in local economic activity. 

The project would not include construction of public utilities or transportation infrastructure that 
would facilitate or promote local land development. The project would replace the existing 
Guadalupe River pedestrian/bicycle trail to mitigate for construction impacts, but the 
reconstructed trail would have the same physical size and capacity as the existing trail. No 
increase in transportation infrastructure that would open new lands to development or support 
increase development density would result. The project would not affect housing or population 
growth and no mitigation would be required. Growth-inducing effects of the project would be 
less than significant. 

D. PUBFIC REVIEW OF NEPA AND CEQA DOCUMENTS 

The corps issued a SEA and Draft FONSI for the proposed project on May 9, 2014 and 
circulated the documents for public and agency review. The review and comment period closed 
on June 9, 2014, and the Corps received one comment. The San Francisco Bay Regional Water 
Quality Control Board (RWQCB) input contained two comments: 


1) RWQCB expressed concern about the lack of erosion control blankets at areas of soil 
containing mercury concentrations of 5 to 20 parts per million (ppm) located above the 
50-year flow level. Erosion of those soils could result in mercury-containing soils being 
washed into the river and adversely affecting water quality. 

2) They requested that the Corps provide an up-to-date construction schedule for the 
project. 

The Corps responded that they will revise the project pans to include erosion-control blankets 
as recommended by the RWQCB and provided the requested construction schedule. 

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CEQA Guidelines §15164(c) states ”An addendum need not be circulated for public review but 
can be included in or attached to the final EIR or adopted negative declaration.” The District will 
attach this EIR Addendum to the previously certified EIS/EIR for the UGRFPP. 


5. CONCLUSION REGARDING APPROPRIATE LEVEL OF REVIEW 

The currently proposed improvements to Reach 12 will occur entirely within the footprint of the 
UGRFPP, and will amend the project described in the 1999 FEIR as described in the Corps 
SEA and summarized in Section 2 above. The UGRFPP Reach 12 project will improve in- 
stream and riparian habitat and will not create new, significant environmental impacts, nor 
increase the severity of impacts beyond the level of significance identified in the certified FEIR. 

Based on the evidence in the whole record, including the 1999 FEIR and technical information 
supporting the information presented herein, the findings contained in District Board Resolution 
No. 2001-51 remain valid. No additional CEQA review, beyond that contained in this EIR 
Addendum, is required for the Reach 12 project. 


6. BIBLIOGRAPHY 

Association of Environmental Professionals. 2014 CEQA Statute and Guidelines. 2014. 

NMFS. Supplemental Biological opinion for the Upper Guadalupe River Flood Control Project, 

February 11, 2005. 

County of Santa Clara et. al., Santa Clara Valley Final Habitat Plan, August 2012. 

DeJager, William, Biologist, U.S. Army Corps of Engineers San Francisco District, email to 

James Manitakos, Environmental Planner II, Santa Clara Valley Water District ( June 20, 2014). 

RWQCB, San Francisco Bay Region. Order R2-2003-0115, Santa Clara Valley Water District, 

and Us. Army Corps of Engineers Upper Guadalupe River Flood Control Project, Santa Clara 

County. December 16, 2003. 

Santa Clara Valley Water District. Resolution No. 2001-51 Adopting Certain Findings For Flood 
Control Work On Guadalupe River From Highway 101 to Interstate 880 and Interstate 280 to 
Blossom Hill Road, certifying the Final Environmental Impact Report/Environmental Impact 
Statement for the Upper Guadalupe River Flood Control Project, November 1999. Board 
Resolution No. 2001-51, August 15, 2001. 

Santa Clara Valley Water District and U.S Army Corps of Engineers. Final Environmental 
Impact Report/Environmental Impact Statement for Upper Guadalupe River Flood Control 
Project. November 1999. 

U.S. Army Corps of Engineers San Francisco District. Reach 12 of the Upper Guadalupe River 
Flood Control Project Supplemental Environmental Assessment (with Final FONSI and 
404(b) (1) Analysis). July 2014. 

United States Department of Commerce, U.S. Census Bureau. State and County Quick Facts, 
San Jose (city), California. May 27, 2014. 


W:\Resource Pros\PROJECTS ARCHIVE PRE-2012 WATERSHEDMJpper Guad\Reach 12\CEQA + NEPAVReach 12 EIR 
Addendum 3VEIR Addendum 3 UGRFPP Reach 12 July2014.pdf 


13 





W:\Resource Pros\PROJECTS ARCHIVE PRE-2012 WATERSHEDMJpper Guad\Reach 12\CEQA + NEPA\Reach 12 EIR 
Addendum 3\EIR Addendum 3 UGRFPP Reach 12 July2014.pdf 


14 





APPENDIX A 


U.S. ARMY CORPS OF ENGINEERS 

SUPPLEMENTAL ENVIRONMENTAL ASSESSMENT 
AND FINAL FINDING OF NO SIGNIFICANT IMPACT 


15 



Reach 12 of the Upper Guadalupe River Flood Risk Management 

Project 

Supplemental Environmental Assessment 
(with FONSI and 404 (b)(1) Analysis) 



U.S. Army Corps of Engineers 
San Francisco District 

July 2014 

























Executive Summary 


This Supplemental Environmental Assessment (EA] is written in compliance with the National 
Environmental Policy Act (NEPA] of 1969 (42 USC § 4321 etseq), as amended, the Council on 
Environmental Quality [CEQ] regulations for Implementing the Procedural Provisions of the NEPA 
(40 CFR §§1500-1508], and United States Army Corps of Engineers (USACE] planning regulations 
(Engineering Regulation (ER] 200-2-2], It presents an evaluation of the potential impacts 
associated with the changes to the project design of the Reach 12 portion of the Upper Guadalupe 
River Flood Risk Management Project. 

The USACE is the federal NEPA lead agency for the Upper Guadalupe River Flood Risk Management 
Project - Reach 12 (Reach 12 project] and the Santa Clara Valley Water District (SCVWD] is the 
state California Environmental Quality Act (CEQA] lead agency. The Reach 12 project is a portion of 
the greater Upper Guadalupe River Flood Risk Management Project, located in Santa Clara County, 
California. 

The proposed actions include excavation and re-grading several portions of the banks adjacent to 
the river channel to create bankfull benches; laying back over-steepened banks in limited areas, 
installation of instream fish habitat structures (e.g., woody debris]; placement of gravel and cobble 
in the channel; raising existing berms to protect adjacent percolation ponds; construction of 
maintenance roads on top of the banks and berms; construction or reconstruction of three access 
ramps; and planting of native vegetation. Overall, the project is intended to create better and more 
habitat complexity, and better and more sustainable geomorphic conditions, throughout the reach. 

The SCVWD and USACE analyzed potential environmental consequences of the greater Upper 
Guadalupe River Flood Risk Management Project in a joint Environmental Impact 
Report/Environmental Impact Statement (EIR/EIS] prepared in 1999; including Reach 12. The 
1999 EIR/EIS evaluated the proposed channel improvements to Reaches A and 6 through 13 of the 
Guadalupe River and sections of two tributary streams, Canoas and Ross Creeks. To date 
improvements were constructed on Reaches A, 6,10B, and 13 of the project; and fish passage 
improvements throughout the river were completed. The 1999 EIR/EIS generally analyzed 
proposed improvements to Reach 12 to include channel widening, reconstruction of and raising 
levees, construction of wetland mitigation ponds, and construction of a Chynoweth Avenue Bridge. 
However, the currently proposed Reach 12 project has changed since the 1999 EIR/EIS was issued. 
It no longer includes many of the elements analyzed in the 1999 EIR/EIS and incorporates design 
modifications that were not examined in the 1999 EIR/EIS. 

The Upper Guadalupe River is located the city of San Jose, Santa Clara County, California (Figure ES- 
1], The river is situated in an urban area of southwestern San Jose, in the highly-urbanized Santa 
Clara Valley. Reach 12 is the most upstream reach of the federal Upper Guadalupe River project. 

The approximately 5,600-foot-long reach extends from Branham Lane Bridge, passing under the 
State Highway 85 overpasses, and ending at Blossom Hill Road (from Station 960+00 to Station 



1018+00] (Figure ES-2], The reach is relatively straight except for a bend halfway down its length. 
The SCVWD operates three [3] percolation ponds adjacent to, but separated from this reach of the 
river, which are used for recharging groundwater through percolation. The reach is separated from 
the ponds by berms. The Almaden Expressway is located west of the west bank, and homes line the 
area east of the east bank along Blossom River Drive and Tonino Drive. The south end of the reach 
has multi-family housing on both sides outside of the channel and percolation ponds areas, while 
the remainder of the west bank has commercial land uses existing or under construction. 

The feasibility study of flood control needs along the upper Guadalupe River was authorized by 
Section 3 of the Flood Control Act of 1917 Pub. L. No. 65-37, § 3, 40 Stat 250 (Aug. 8,1917], 

Reach 12 is the most upstream reach of the federal Upper Guadalupe Flood Risk Management 
Project and does not generally pose a flood risk to the surrounding neighborhoods because the 
channel is generally sufficient to contain flows up to about the 1 percent annual occurrence level. 
However, the downstream portion of the reach does not meet USACE risk and uncertainty 
standards for containing a 1 percent flow. 

The reach was channelized in the 1970s into a roughly trapezoidal shape in most locations. The 
result is a channel shape that does not provide good floodplain functions. In certain locations the 
banks are over-steepened, creating hazards. The entire river is deficient in coarse sediment, gravel 
and cobble in particular. This has negative effects on channel morphology and stability as well as 
wildlife habitat and riparian forest regeneration. 

The proposed action would improve the channel morphology by adding new floodplains and adding 
coarse sediment to the low-flow channel. The proposed action would improve habitat conditions 
for fish and wildlife by creating riparian forest and shaded riverine aquatic (SRA] cover. Placement 
of woody debris would improve aquatic habitat conditions. Vegetation replanting would not only 
mitigate for impacts within this reach from the channel work, it would also provide additional 
riparian forest and SRA cover mitigation for impacts in other reaches associated with the overall 
Upper Guadalupe Flood Risk Management Project. 

Project Need: The federal Upper Guadalupe River Flood Risk Management Project is needed to 
reduce the risk of the Upper Guadalupe River flooding adjacent urban areas; however, the 
construction of the entire project would result in significant impacts to riparian forest and shaded 
riverine aquatic cover, and urban forest (1999 EIS/EIR, SCVWD and USACE], The 1999 EIS/EIR 
discusses mitigation for these impacts. Those requirements include creation of 1.47 acres of 
freshwater wetlands, 20.89 acres of riparian forest, 4,886 linear feet of SRA cover and 1,720 linear 
feet of undercut bank habitat (San Francisco Bay RWQCB, 2003], While the current project design 
would not provide as much mitigation as discussed in the 1999 EIR/EIS, it would provide some 
additional mitigation for other reaches of the overall Upper Guadalupe River Flood Risk 
Management Project. The proposed Reach 12 project would result in approximately 2.22 acres of 
riparian forest mitigation; of this 0.55 acre would be available for mitigation for riparian forest 



mitigation in other reaches of the overall Upper Guadalupe River project. The proposed project 
would also provide 658 linear feet of SRA cover mitigation, of which 271 linear feet could be used to 
mitigate for impacts in other reaches. Additionally, following construction, the reach would be 
more stable and provide improved fish habitat over existing conditions. 

The Guadalupe River has flooded nearby communities repeatedly, with the most recent flooding 
event occurring in 1998. In 1995 floodwaters submerged downtown San Jose and more than 150 
homes. The overall Upper Guadalupe River Flood Risk Management Project is needed to reduce the 
risk of the upper reaches of the river flooding adjacent urban areas. Construction of the overall 
project would result in unavoidable significant impacts to riparian forest and shaded riverine 
aquatic cover that must be mitigated. Reach 12 of the Upper Guadalupe River project would 
provide some mitigation to compensate for some of these adverse impacts. Additional mitigation 
work would be completed in other reaches of the river. 



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Project Purpose: The primary purpose of the proposed Reach 12 project is to enhance habitat 
conditions for fish and wildlife above current conditions and to create sufficient quantities of 
riparian forest and SRA cover in order to provide advance, on site mitigation for the overall Upper 
Guadalupe River Flood Risk Management Project. Secondary objectives include preventing 
floodwaters from affecting adjacent percolation ponds and improving access to the channel for 
maintenance purposes. 

The 1999 EIR/EIS details impacts of the overall Upper Guadalupe River Flood Risk Management 
Project alternatives, including the no-action alternative. Impacts resulting from the no-action 
alternative have not changed since the publication of the 1999 EIR/EIS. The impacts resulting 
from implementation of the alternatives to the proposed action, including the no action alternative, 
are provided in the original 1999 EIR/EIS and this document only discloses the impacts of the 
proposed design changes that are not disclosed in the 1999 document. Resources that were 
adequately addressed in the EIS/EIR include: geology, soils, and seismicity (soil quality is 
addressed in this EA, however]; mineral resources; energy consumption or generation, 
environmental justice, growth inducing impacts, and hazardous and toxic materials. The reader is 
referred to the 1999 EIS/EIR for details about potential impacts to these resources. 

Table ES-1 provides an overview of the environmental resources analyzed in this Supplemental EA, 
the potential impacts of the propose project on the respective resource, and avoidance, 
minimization and mitigation measures to ensure impacts are reduced to less than significant. 

The USACE has prepared this Final Supplemental EA to assess and disclose the potential impacts of 
the proposed project on the quality of the environment within the proposed project area. Based on 
this assessment, it has determined that the potential impacts of the proposed Reach 12 project 
would not rise above those previously disclosed in the 1999 EIS/EIR. However, similar to the 1999 
EIS/EIR, avoidance, minimization, and mitigation measures are proposed to ensure that the 
proposed action does not significantly affect the surrounding environmental resources. The 
potential impacts and proposed avoidance, minimization, and mitigation measures are summarized 
in Table ES-1. Based on these findings, a Finding of No Significant Impact [FONSI] was prepared 
pursuant to 33 CFR pt. 230. 



Table ES-1 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 

Flood Risk 
Management 

Impact H&H-l: Result in significant flooding 
downstream of the project area. 

Less than significant 

None 

Flows, Currents, 

and Circulation 

Impact H&H-2: Result in significant adverse 
effects on flows, currents, and circulation. It 

Less than significant 

during construction 

Beneficial following 
construction 

None 

Ground Water 

(Aquifer 

recharge) 

Impact H&H-3: Result in substantial depletion 
of groundwater or interfere with groundwater 
recharge. 

Less than significant 

during construction. 

None 

Soil 

Quality 

Impact SQ-1: Degrade sediment quality during 
construction or after construction. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure SQ-1: 

Comply with the San Francisco Bay RWQCB’s 
requirements for reuse of mercury-laden sediment 
(see Table 14). 

Avoidance and Minimization Measure SQ-2: 

Utilize erosion control measures to ensure that 
mercury-laden sediment does not erode into the 
adjacent river. 

Avoidance and Minimization Measure SQ-3: 

Utilize best management practices to ensure that 
mercury-laden sediment does not erode into the 
adjacent river. 

Impact SQ-2: Expose water or biological 
receptors to concentrations of mercury that 
would violate standards 

Less than significant 

with Avoidance and 

Minimization Measures 












Table ES-1 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 




Avoidance and Minimization Measure SQ-4: 

All stockpiling of sediment shall be conducted in 
such a manner that prevents sediment from 
eroding into adjacent areas or streams. 

Avoidance and Minimization Measure SQ-5: 

Dispose of mercury-laden sediment at approved 
upland facilities. 

Water Quality 

Impact WQ-1: Violate any water quality 
standard or waste discharge standard set by the 
RWQCB or substantially degrade water quality. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure WQ-1: 

Comply with erosion control measures identified in 
the Construction General National Pollution 
Discharge Elimination System (NPDES) permit. 

Avoidance and Minimization Measure WQ-3: 

Comply with the mercury and diazinon TMDLs for 
Guadalupe River and ensure that concentrations of 

Impact WQ-2: Increase the concentration of 
any CWA 303(d) substance identified for 
Guadalupe River (mercury, diazinon, or trash) or 
violate the river’s TMDLs (mercury and 
diazinon). 

Less than significant 

with Avoidance and 

Minimization Measures 










Table ES-1 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Impact WQ-3: Substantially contribute to 
runoff water which would exceed the capacity of 
existing or planned stormwater drainage 
systems. 

Less than significant 

with Avoidance and 

Minimization Measures 

CWA 303(d) constituents listed for Guadalupe River 
(mercury, diazinon, and trash) are not increased. 

Avoidance and Minimization Measure WQ-1: 

Comply with erosion control measures identified in 
the Construction General National Pollution 
Discharge Elimination System (NPDES) permit. 

Biological 

Environment 

Impact BIO-1: Result in a substantial loss of 
riparian forest or SRA cover that would not 
reestablish within 10 years following 
construction. 

Less than significant 

with Avoidance, 
Minimization, and 
Mitigation Measures 

Avoidance and Minimization Measure BIO-1: 

Vegetation not proposed for removal would be 
protected during construction. 

Mitigation Measure BIO-2: Replant vegetation 
according to the planting designs for the project. 

Avoidance and Minimization Measure BIO-3: 

Update and revise the 1999 MMP. 

Impact BIO-2: Result in permanent loss of 
wetlands or other waters of the United States. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BIO-3: 

Update and revise the 1999 MMP 










Table ES-1 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Impact BI0-3: Result in fish and wildlife 
avoiding the project area following 
establishment of riparian forest and SRA cover. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BIO-3: 

Update and revise the 1999 MMP 3 

Impact BIO-4: Result in take of listed species 
that could not be mitigated. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BI0-4: 

Monitor and relocate native fish during dewatering 

activities. 

Impact BIO-5: Result in take of protected birds 
or their nests. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BIO-5: 

Conduct bird surveys prior to construction. 

Air Quality 

Impact AQ-1: Estimated emissions exceed 
General Conformity de minimis thresholds. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure AQ-1: 

Utilize Tier-4 off-road equipment. 

Impact AQ-2: Estimated emissions exceed 
applicable BAAQMD construction emissions 
thresholds. 

Less than significant 

with Avoidance and 

Minimization Measures 

Historic and 

Cultural 

Resources 

Impact HIST-1: Adversely affect a resource that 
is listed or has the potential to be listed on the 
National Register. 

None 

None 

Noise 

Impact NOISE-1: Expose sensitive receptors to 
nuisance noise (i.e., nuisance noise within 500 
feet of residential uses or 200feet of commercial 
or office uses). 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure NOISE- 

1: Limit construction hours 

Avoidance and Minimization Measure NOISE- 

21 Implement best management practices 














Table ES-1 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 

Recreation 

Impact REC-1: Temporary closure of a portion 
of the Guadalupe River Recreational Trail 

Less than significant 

with Avoidance and 

Minimization Measures 

Mitigation Measure REC-1: Implement detour 
around the closed section of trail 

Impact REC-2: Degrade the condition of the 
existing paved recreation trail 

Less than significant 

with Avoidance and 

Minimization Measures 

Mitigation Measure REC-2: Repair and/or re¬ 
pave trail to existing condition after construction 

Transportation 
and Traffic 

Impact TT-1: Substantially interfere with 
surrounding traffic which would result in major 
delays. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure TT-1: 

Prepare and implement a traffic control plan. 

Avoidance and Minimization Measure TT-3: 

Minimize interference with existing traffic. 

Impact TT-2: Damage roads or highways. 

Less than significant 

with Mitigation Measures 

Mitigation Measure TT-4: Repair and 
rehabilitate roads damaged by construction 
vehicles 

Impact TT-3: Result in injury or harm to other 
drivers, pedestrians, bikers, or others using any 
form of transportation in the project area. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure TT-1: 

Prepare and implement a traffic control plan. 

Avoidance and Minimization Measure TT-2: 

Utilize traffic control safety measures. 

Land Use 

Classification 

Impact LU-1: Conflict with the adopted General 
Plan designations, land uses, or physical 
arrangement of the community. 

Less than significant 

None 













Table ES-1 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 

Aesthetics 

Impact VR-1: Losses of vegetative cover in 
limited portions of the river channel and the west 
bank due to construction activity and selective 
removal of non-native trees and shrubs. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure VIS-1: 

Retain native vegetation to the maximum extent 
practicable. 

Mitigation Measure BIO-2: Replant vegetation 
according to the planting designs for the project. 

Impact VR-2: Temporary views of construction 
activities and materials. 

Less than significant 

None 

Impact VR-3: New berms along the percolation 
ponds. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure VIS-1: 

Retain native vegetation to the maximum extent 
practicable. 

Mitigation Measure VIS-3: Hydroseed areas 
where vegetation would be removed. 

Impact VR-4: Loss of trees behind houses on the 
east bank, downstream portion of the reach. 

Less than significant 

Avoidance and Minimization Measure VIS-2: 

Retain non-invasive non-native native trees in this 
area to the extent practicable. 

Public Utilities, 
Facilities, and 

Services. 

Impact PUS-1: Potential interference with 

Police and Fire protection services. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure PUS-1: 

Notify police and fire protection services regarding 
construction and implement site security patrol. 

Impact PUS-2: Potential interference with 
utility service. 

Less than significant 

with Avoidance and 

Mitigation Measure PUS-2: Identify and 
coordinate relocation or protection of utilities. 













Table ES-1 

Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 



Minimization Measures 

Avoidance and Minimization Measure PUS-3: 

Avoid placement of trees in locations that could 
interfere with utilities. 

Public Health 
and Safety 

Impact PHS-1: Potential public safety impacts 
due to unauthorized entry to the construction 
area or the reach after construction is complete. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Mitigation Measure PHS-1: 

Provide warning signs, install fencing and 
barricades, and implement site security patrol at 
construction site. 

Avoidance and Mitigation Measure PHS-2: 

Install permanent access control measures post¬ 
construction. 

Impact PHS-2: Construction Hazards to 

Vehicles and Pedestrians. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Mitigation Measure PHS-3: 

Identify truck routes and construction zones prior 
to project commencement. 

Avoidance and Mitigation Measure PHS-4: 

Notify residents of construction schedule and 
proposed traffic detours. 


Impact PHS-3: Displacement of Homeless 

Persons Occupying the Reach. 

Less than significant 

None 











TABLE OF CONTENTS 


1.0 Introduction.1 

1.1 NEPA Background.1 

1.2 Project Location.2 

1.3 Study Authority.3 

1.4 Purpose and Need for Proposed Action.5 

1.4.1 Habitat Mitigation Goals for the Proposed Action.6 

1.5 Scope of Analysis.6 

1.6 Scope of Alternatives.8 

1.7 Unresolved Issues.9 

2.0 Proposed Action.9 

2.1 Site Constraints.15 

2.2 Site Preparation.15 

2.3 Removal of Non-native and Invasive Plant Species.17 

2.4 Channel Modification.17 

2.4.1 Flood Bench Creation.19 

2.4.2 Gravel Augmentation.20 

2.4.3 Installation of Instream Structures.34 

2.5 Raising Existing Berms.35 

2.6 Maintenance Road and Ramp Construction.37 

2.8 Planting Vegetation.40 

2.9 Installation of Fencing.46 

2.10 Plant and Reach Maintenance.46 

2.11 Summary of Construction Activities.47 

3.0 Existing Conditions and Consequences of the Proposed Action.51 

3.1 Hydrology and Hydraulics.60 

3.1.1 Flood Risk Management.61 

3.1.1.1Potential Impacts and Mitigation.62 

3.1.2 Flow, Currents, and Circulation.62 

3.1.2.1Potential Impacts and Mitigation.62 

3.1.3 Ground Water (Aquifer Recharge].63 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page i 


































4.0 


3.1.3.1Potential Impacts and Mitigation.63 

3.2 Geology, Soils, and Seismicity.64 

3.3 Soil Quality 65 

3.3.1 Potential Impacts and Mitigation Measures.69 

3.4 Water Quality 73 

3.4.1 Potential Impacts and Mitigation Measures.80 

3.5 Biological Environment.84 

3.5.1 Existing Habitat.85 

3.5.2 Existing Fish and Wildlife.85 

3.5.2.1Special Status Species.91 

3.5.3 Potential Impacts and Mitigation Measures.98 

3.6 Air Quality 117 

3.6.1 Potential Impacts and Mitigation Measures.121 

3.7 Historic and Cultural Resources.125 

3.7.1 Potential Impacts and Mitigation Measures.130 

3.8 Noise 130 

3.8.1 Potential Impacts and Mitigation Measures.133 

3.9 Recreation 135 

3.9.1 Potential Impact and Mitigation Measures. Error! Bookmark not defined. 

3.10 Transportation and Traffic.138 

3.10.1 Potential Impacts and Mitigation Measures.139 

3.11 Land Use Classification.144 

3.11.1 Potential Impacts and Mitigation Measures.148 

3.12 Aesthetics 148 

3.12.1 Potential Impacts and Mitigation Measures.149 

3.13 Public Facilities, Utilities, and Services.150 

3.13.1 Potential Impacts and Mitigation Measures.151 

3.14 Public Health and Safety.153 

3.14.1 Potential Impacts and Mitigation Measures.153 

3.15 Irreversible Changes and Irreversible Commitment of Resources.155 

Other Required Analysis.156 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page ii 





























4.1 Cumulative Impacts.156 

4.2 Interrelated and Interdependent Activities.156 

5.0 Environmental Compliance.157 

6.0 Public and Agency Comments.163 

7.0 Determination and Statement of Findings.165 

8.0 Documents Incorporated by Reference.166 

9.0 List of Preparers and Contributors.167 

10.0 References.168 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page iii 












LIST OF TABLES 

Table 1. Non-native and Invasive Plants Proposed for Removal.18 

Table 2. Site 1 Proposed Gravel Augmentation and Channel Modification.23 

Table 3. Site 2 Proposed Gravel Augmentation and Channel Modification.28 

Table 4. Site3 Proposed Gravel Augmentation and Channel Modification.32 

Table 5. Instream Structures, Type, Location and Purpose.34 

Table 6. Berm Raising Locations, Lengths, and Elevation Data.36 

Table 7. Maintenance Access Road Limits.37 

Table 8. Proposed Channel Maintenance Access Ramps.39 

Table 9. Reach 12 Planting Zone Palette.44 

Table 10. Reach 12 In-Stream Planting Palette.45 

Table 11. Summary of Reach 12 Construction Activities.47 

Table 12. Potential Effects and Proposed Avoidance, Minimization, and 

Mitigation.52 

Table 13. Upper Guadalupe River Reach 12 Sediment Sampling and 

Analysis Results.66 

Table 14. Requirements for Reusing Soil with Mercury.69 

Table 15. Reach 12 Excavation, Fill and Aggregate Requirements.71 

Table 16. WDR Order No. R2-2003-0115 Water Quality Limitation 

Measurements.74 

Table 17. Water Quality Measurements taken during Construction of 

Reach 10B (2012].75 

Table 18. Water Quality Measurements taken during Construction of Reach 6.77 

Table 20. Existing Land Cover Habitat Types.86 

Table 21. Reach 10B Fish Removal and Relocation.92 

Table 22. Special Status Species with the Potential to be Present in the 

Action Area.93 

Table 23. Impacts to Land Cover (Habitats].99 

Table 24. Habitat and Vegetation Mitigation Requirements.105 

Table 25. Proposed Planting Zones and Palettes and Mitigation Equivalent.106 

Table 26. Proposed Vegetation Replanting Mitigation.113 

Table 27. Habitat Impact and Proposed Mitigation Calculations.114 

Table 28. Ambient Air Quality Attainment Status.119 

Table 29. BAAQMD Construction Emissions Thresholds.120 

Table 30. General Conformity Rule.120 

Table 31. Daily Construction Emissions Estimates.123 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page iv 


































Table 32. 
Table 33. 
Table 34. 

Table 35. 

Table 36. 


Annual Construction Emissions Estimates.124 

Annual GHG Emissions Estimates.125 

Typical Noise Levels for Common Construction 

Equipment (at 50 feet].134 

Number of Truck Hauls Required to Transport 

Equipment and Construction Material.140 

Real Estate Require for the Proposed Reach 12 Project.145 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page v 









TABLE OF FIGURES 

Figure 1. Upper Guadalupe River Flood Risk Management Project - Reach 12 Location.3 

Figure 2. Upper Guadalupe River Flood Risk Management Project - Reach 12 and 

Other Reaches.4 

Figure 3. Reach 12 Proposed Project Components - Upstream.11 

Figure 4. Reach 12 Proposed Project Components - Downstream.13 

Figure 6. Reach 12 Generalized Sites for Gravel Augmentation.22 

Figure 7. Site 1 Proposed Gravel Augmentation from Stations 

1018+50 to 1016+40.24 

Figure 8. Site 1 Proposed Gravel Augmentation from Stations 

1009+00 to 1004+30.25 

Figure 9. Site 1 Thalweg Profile and Cross Sections from Stations 

1018+50 to 1044+30.26 

Figure 10. Site 1 - Gravel Augmentation Site from Stations 

1018+00 to 1004+00.27 

Figure 11. Site 2 Proposed Gravel Augmentations and Stockpile Site from Stations 

996+50 to 991+50.29 

Figure 12. Site 2 Proposed Gravel Augmentation and Gravel Stockpile from Station 

986+00 to 982+00.30 

Figure 13. Site 2 Thalweg Profile and Cross Sections from Stations 

996+50 to 982+70.31 

Figure 14. Site 3 Proposed Gravel Augmentation and Thalweg Profile from 

Stations 963+00 to 961+00.33 

Figure 15. Typical Planting Zones.43 

Figure 16. Sediment Mercury Sampling Locations, Depths, and Results .68 

Figure 17. Requirements for Reusing Sediment Containing Mercury in the 

Project Area.70 

Figure 19. Existing Land Cover (Habitat] in Reach 12 

(upstream portion of the reach].87 

Figure 20. Existing Land Cover (Habitat] in Reach 12 

(downstream portion of the reach].89 

Figure 21. Proposed Vegetation Removal in the Upstream Portion of Reach 12.101 

Figure 22. Proposed Vegetation Removal in the Downstream Portion of Reach 12.103 

Figure 23. Proposed Planting Zones.108 

Figure 24. Proposed Replanting in the Upstream Portion of Reach 12.109 

Figure 25. Proposed Replanting in the Downstream Portion of Reach 12.Ill 

Figure 26. Potential Recreation Trail Detour Routes.137 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page vi 




























Figure 27. 


Major Roads and Construction Haul Routes 


141 


Upper Guadalupe Flood Control Project, Reach 12 
Environmental Assessment 

United States Army Corps of Engineers Page vii 





APPENDICIES 


Appendix A: 

Upper Guadalupe River Reach 12 Sediment Sampling and Analysis Report (June 

2013] 

Appendix B: 

Reach 6 [2011] and Reach 10B [2012] Water Quality Sampling and Analysis 

Appendix C: 

Upper Guadalupe Reach 12 Air Quality Assessment: CalEEMOD Notes (2014] 

Appendix D: 

CWA 404(b](l] Analysis 

Appendix E: 

Upper Guadalupe River Flood Control Project Supplemental Biological Opinion, File 
Number 151422SWR00SR589 (NMFS 2005] 

Appendix F: 

Waste Discharge Requirement and Water Quality Certification for the Santa Clara 
Valley Water District and United States Army Corps of Engineers Upper Guadalupe 
River Flood Control Project, City of San Jose, Santa Clara County. Order No. R2- 
2003-0115 (San Francisco RWQCB 2003], 


(Appendices provided digitally] 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page viii 




ACRONYMS AND ABBREVIATIONS 


ATM 

Adaptive Management Team 

BAAQMD 

Bay Area Air Quality Management District 

BO 

Biological Opinion 

°C 

Degrees Celsius 

CAA 

Federal Clean Air Act 

CAAQD 

California Ambient Air Quality Standards 

CAR 

Coordination Act Report 

CCAA 

California clean air act 

CDFW 

California Department of Fish and Wildlife 

CEQ 

Council on Environmental Quality 

CEQA 

California Environmental Quality Act 

CFR 

Code of Federal Regulations 

CH 

Critical habitat 

CIE 

Channel Improvement Easements 

CNEL 

Community Noise Equivalent Level 

CO 

Carbon monoxide 

CWA 

Clean Water Act 

dB 

Decibels 

dBA 

A-weighted decibels 

DWR 

Department of Water Resources 

EA 

Environmental Assessment 

EIR 

Environmental Impact Report 

EIS 

Environmental Impact Study 

ER 

Engineering Regulation 

ESA 

Endangered Species Act 

°F 

Degrees Fahrenheit 

FE 

Federal endangered 

FLPE 

Flood Levee Protection Easements 

FT 

Federal threatened 

FONSI 

Finding of No Significant Impact 

FWCA 

Fish and Wildlife Coordination Act 

GHG 

Greenhouse gases 

HEP 

Habitat Evaluation Procedure 

Hz 

Hertz 

Ldn 

Day Night Average Level 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page ix 




Leg 

Lmin 

Lmax 

lb/day 

LEDPA 

MBTA 

mg/kg 

mg/L 

MMP 

NAAQS 

NEPA 

NHPA 

NMFS 

N0 2 

NOx 

NTU 

Pb 

PM 

ppm 

PRE 

ROD 

ROG 

ROW 

RWQCB 

SCVWD 

SHPO 

SIP 

SJWC 

S0 2 

SR 

SRA 

ST 

TMDL 

U.S. 

USACE 

use 

USDA 


Equivalent continuous noise level 
Minimum sound levels 
Maximum sound levels 
Pounds per day 

Least Environmental Damaging Practicable Alternative 

Migratory Bird Treaty Act 

Milligrams per kilograms 

Milligrams per liter 

Mitigation Monitoring Plan 

National Ambient Air Quality Standards 

National Environmental Policy Act 

National Historic Preservation Act 

National Marine Fisheries Service 

Nitrogen dioxide 

Nitrogen oxides 

Nephelometric Turbidity Units 

Lead 

Particle matter 
Parts per million 
Permanent Road Easements 
Record of Decision 
Reactive organic gases 
Right of Way 

Regional Water Quality Control Board 
Santa Clara Valley Water District 
State Historic Preservation Officer 
State Implementation Plan 
San Jose Water Company 
Sulfur dioxide 
State Route 

Shaded riverine aquatic 
State threatened 
Total Maximum Daily Load 
United States 

United States Army Corps of Engineers. 

United States Code 

United States Department of Agriculture 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page x 




USEPA 

USFWS 

USGS 

VOC 

WDR 


United States Environmental Protection Agency 
United States Fish and Wildlife Service 
United States Geological Service 
Volatile organic compound 
Waste Discharge Requirement 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page xi 




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Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page xii 




1.0 


Introduction 


This supplemental Environmental Assessment (EA] is written in compliance with the National 
Environmental Policy Act (NEPA] of 1969 (42 USC § 4321 etseq), as amended, the Council on 
Environmental Quality (CEQ] Regulations for Implementing the Procedural Provisions of the NEPA 
(40 CFR §§1500-1508], and United States Army Corps of Engineers (USACE] Planning Regulations 
(Engineering Regulation (ER] 200-2-2], It presents an evaluation of the potential impacts 
associated with the changes to the project design of the Reach 12 portion of the Upper Guadalupe 
River Flood Risk Management Project. 

The USACE is the federal NEPA lead agency for the Upper Guadalupe River Flood Risk Management 
Project - Reach 12 (Reach 12 project] and the Santa Clara Valley Water District (SCVWD] is the 
state California Environmental Quality Act (CEQA] lead agency. The Reach 12 project is a portion of 
the greater Upper Guadalupe River Flood Risk Management Project, located in Santa Clara County, 
California. 

The proposed actions include excavation and re-grading of portions of the banks adjacent to the 
river channel to create bankfull benches; laying back over-steepened banks; installation of instream 
fish habitat structures, placement of gravel in the channel; raising existing berms to protect 
adjacent percolation ponds; construction of maintenance roads on top of the banks and berms; 
construction of three access ramps; removal of invasive and some other non-native vegetation; and 
planting of native vegetation. Overall, the proposed project is intended to create better and more 
habitat complexity and sustainable geomorphic conditions throughout the reach. 

1.1 NEPA Background 

The SCVWD and USACE analyzed potential environmental consequences of the overall Upper 
Guadalupe River Flood Risk Management Project in a joint Environmental Impact 
Report/Environmental Impact Statement (EIR/EIS] prepared in 1999. The 1999 EIR/EIS evaluated 
channel improvements to Reaches A and 6 through 13 of the Guadalupe River and portions of two 
tributary streams, Canoas and Ross Creeks. To date improvements were constructed on Reaches A, 
6, and 10B of the project; and fish passage improvements throughout the river were completed. 

The 1999 EIR/EIS generally analyzed proposed improvements to Reach 12 as well. Proposed 
Reach 12 improvements included channel widening, reconstruction of and raising levees, 
construction of wetland mitigation ponds, and construction of a Chynoweth Avenue Bridge. 
However, the currently proposed Reach 12 project has changed since the 1999 EIR/EIS was issued. 
It no longer includes many of the elements analyzed in the 1999 EIR/EIS and incorporates design 
modifications that were not examined in the 1999 EIR/EIS. 

In 2004, a supplemental EA was prepared for the overall Upper Guadalupe River Project. This EA 
supplemented the 1999 EIS/EIR. The purpose of this supplemental EA was to change the overall 
time to construct the project from 25 years to 9 years. This supplemental EA did not affect the 
original construction plans for Reach 12. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 1 




The CEQ and USACE have provisions for preparing supplemental NEPA documents when project 
conditions change. Section 1509.9 of the CEQ's regulations discusses draft, final, and supplemental 
statements. Section 1502.9(c] provides that agencies: 

(1) Shall prepare supplements to either draft or final environmental impact 
statements if: 

(i) The agency makes substantial changes in the proposed action that are 
relevant to environmental concerns; or 

(ii) There are significant new circumstances or information relevant to 
environmental concerns and bearing on the proposed action and its impacts. 

However, in this case, the changes are neither substantial nor significant, and thus do not require 
the preparation of a supplemental EIS. Nonetheless, the new information and developments of this 
project do require a supplemental EA to verify that the project changes do not rise to the level of 
significant. Engineering Regulation 200-2-2: Procedures for Implementing NEPA provides 
guidance on USACE responsibilities for meeting NEPA requirements. Section 7 of ER 200-2-2 lists 
actions that normally require an EA but not necessarily an EIS and includes "changes in 
environmental impacts which were not considered in the [original] project EIS or EA.” Because the 
design of this reach has changed since the 1999 EIR/EIS was issued, this EA supplements the 1999 
EIR/EIS by reevaluating the potential environmental consequences of the currently proposed 
Reach 12 improvements as well as proposed measures to avoid, minimize, and mitigate 
environmental effects. The 1999 EIR/EIS is incorporated by reference in this document. 

At various points, this document discusses both the overall Upper Guadalupe River Flood Risk 
Management Project for which the 1999 EIS/EIR was prepared and the proposed Reach 12 project. 
For clarification, this document refers to the overall Upper Guadalupe River Flood Risk 
Management Project as the ‘overall Upper Guadalupe River project' or ‘overall project’ and the 
propose Reach 12 project as the 'proposed project’ or 'proposed action'. 

1.2 Project Location 

The Guadalupe River is located the city of San Jose, Santa Clara County, California (Figure 1], The 
upper Guadalupe River is situated in an urban area of southwestern San Jose, in the highly- 
urbanized Santa Clara Valley. Reach 12 is the most upstream reach of the federal Upper Guadalupe 
River Flood Risk Management Project. The approximately 5,600-foot-long Reach 12 portion of the 
project extends from Branham Lane Bridge, passing under the State Highway 85 overpasses, and 
ending at Blossom Hill Road (from Station 960+00 to Station 1018+00] (Figure 2], This reach is 
relatively straight except for a bend halfway down its length. The SCVWD operates three (3] 
percolation ponds adjacent to, but separated from the reach by berms. The ponds are used for 
recharging groundwater through percolation. The Almaden Expressway, Sanchez Drive, 
commercial uses, and multi-family residential uses are located west of the west bank, and single¬ 


upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 2 




family and multi-family residential uses are located in the area east of the east bank along Blossom 
River Drive and Tonino Drive. 

1.3 Study Authority 

The feasibility study of flood control needs along the upper Guadalupe River was authorized by 
Section 3 of the Flood Control Act of 1917, Pub. L. No. 65-37, §3. 40 Stat. 250 (Aug. 8,1917] 


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Figure 1. Upper Guadalupe River Flood Risk Management Project Reach 12 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 3 










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Figure 2. Upper Guadalupe River Flood Risk Management Project - Reach 12 
and Other Reaches 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 4 

















1.4 


Purpose and Need for Proposed Action 


The Guadalupe River watershed has a highly urbanized landscape with a long history of agricultural 
practices. As a result of urbanization, the surrounding landscape surface has become increasingly 
impervious. Reservoirs in the upper watershed, as well as Lake Almaden upstream of the river, 
have also reduced coarse sediment supply to the channel. Reduced course sediment supply and the 
development of urban hydrology characteristics in the watershed have resulted in more erosive 
flows incising the channel. 

The upper Guadalupe River has flooded communities repeatedly, with the most recent flooding 
event occurring in 1998. In 1995 floodwaters submerged portions of downtown San Jose and more 
than 150 homes. The purpose of and need for the overall Upper Guadalupe Flood Risk Management 
Project is to reduce the risk of such flooding in the adjacent San Jose communities. However, 
construction of the overall Upper Guadalupe River Flood Risk Management Project would result in 
unavoidable significant impacts to riparian forest and shaded riverine aquatic cover which must be 
mitigated. 

Reach 12 is the most upstream reach of the federal Upper Guadalupe Flood Risk Management 
Project and does not generally pose a flood risk to the surrounding neighborhoods because the 
channel is sufficient to contain flows up to about the 1 percent annual occurrence level. However, 
the reach is almost entirely artificial in configuration, having been constructed in the 1970s and 
used for instream percolation ponds for many years. As a result of both local and watershed 
conditions, the geomorphology of the reach is not optimum for its stability and its floodplain 
functions and habitat conditions are suboptimal. 

The proposed project would improve the channel morphology and floodplain functions of the 
reach. Additionally, vegetation replanting would not only mitigate for habitat impacts from this 
construction work, but would also provide additional riparian forest and shaded riverine aquatic 
(SRA] cover mitigation for impacts in other reaches associated with the overall Upper Guadalupe 
Flood Risk Management Project. 

Project Need: The overall Upper Guadalupe River Flood Risk Management Project is needed to 
reduce the risk of the Upper Guadalupe River flooding adjacent urban areas; however, its 
construction would result in significant impacts to riparian forest, SRA cover, and urban forest 
(1999 EIS/EIR, SCVWD and USACE], The 1999 EIS/EIR discusses mitigation for these impacts. 
Those requirements include creation of 1.47 acres of freshwater wetlands, 20.89 acres of riparian 
forest, 4,886 linear feet of SRA cover and 1,720 linear feet of undercut bank (San Francisco Bay 
RWQCB, 2003], While the current project design for this reach would not provide as much 
mitigation as discussed in the 1999 EIR/EIS, it would provide some additional mitigation for other 
reaches of the overall Upper Guadalupe River Flood Risk Management Project. The proposed Reach 
12 project would result in approximately 2.22 acres of riparian forest mitigation, of which 0.55 acre 
would be available for mitigation for riparian forest mitigation in other reaches of the overall Upper 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 5 




Guadalupe River project. The proposed project would also provide 658 linear feet of SRA cover 
mitigation, of which 271 linear feet could be used to mitigate impacts in other reaches. 

Additionally, following construction, the reach would have a more geomorphically sound 
configuration and would provide improved fish habitat over existing conditions. 

The Guadalupe River has flooded communities repeatedly, with the most recent flooding event 
occurring in 1998. In 1995 floodwaters submerged downtown San Jose and more than 150 homes. 
The overall Upper Guadalupe River project is needed to reduce the risk of the upper reaches of the 
river flooding adjacent urban areas. Construction of the Upper Guadalupe River Flood Risk 
Management Project would result in unavoidable significant impacts to riparian forest and shaded 
riverine aquatic cover that must be mitigated. Reach 12 of the overall project would serve as a 
mitigation reach to compensate for some of these adverse impacts. Additional mitigation work 
would be done in other reaches. 

Project Purpose: The primary purpose of the proposed Reach 12 project is to enhance habitat 
conditions for fish and wildlife above current conditions and to create sufficient quantities of 
riparian forest and SRA cover in order to provide advance, on site mitigation for the overall Upper 
Guadalupe River Flood Risk Management Project. Secondary objectives include preventing 
floodwaters from affecting adjacent percolation ponds and improving access to the channel for 
maintenance purposes. 

1.4.1 Habitat Mitigation Goals for the Proposed Action 

The proposed Reach 12 project is intended to attain multiple beneficial environmental objectives 
while meeting the overall project's basic purpose of flood risk management. The purpose of the 
proposed project is to establish riparian forest and SRA cover of sufficient quality to compensate for 
a portion of the overall Upper Guadalupe River Flood Risk Management Project related impacts. 
Habitat goals for the proposed action include: 

• Develop and maintain an improved riparian forest plant community; 

• Develop and maintain bank stability and moderate flows; 

• Develop and maintain habitat interspersion and connectivity; 

• Develop and maintain nesting, foraging and escape cover; 

• Provide shade to aquatic habitats; 

• Provide instream refugia for salmonids and other aquatic organisms; and 

• Provide organic matter input. 

1.5 Scope of Analysis 

The scope of this analysis in terms of geographic extent and duration is defined by the potential 
direct, indirect, and cumulative impacts from the proposed changes to the Reach 12 portion of the 
overall Upper Guadalupe River Flood Risk Management Project. The Council on Environmental 
Quality (CEQ] regulations for implementing the National Environmental Policy Act (NEPAJ (40 CFR 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 6 





§§ 1500-1508] define direct effects as those that are caused by an action, and occur at the same 
time and place as the action (40 CFR § 1508.8a], Indirect effects are defined as reasonably 
foreseeable to be caused by an action, but may occur later in time or further removed in distance 
(40 CFR § 1508.8b], Cumulative effects "results from the incremental impact of the action when 
added to other past, present, and reasonably foreseeable future actions regardless of what agency 
or person undertakes those other actions" (40 CFR § 1508.7], 

The geographic scope of this analysis is limited to the footprint of the proposed project and 
downstream river water that may be affected, in terms of duration, the scope of analysis covers the 
proposed 2-3 years of construction and 4 years of maintenance, for a total of 6-7 years. There is a 
potential for a floodwall to be constructed in approximately 10 years; however, at this time it is not 
certain if this portion of the project would be constructed. Should the floodwall be constructed in 
the future, it would undergo additional environmental analysis. 

As previously mentioned, this document is a Supplemental EA intended to supplement the existing 
1999 EIR/EIS for the Upper Guadalupe River Flood Risk Management Project. A supplement to the 
1999 EIR/EIS is required because the current design proposal for Reach 12 is different from the 
design proposal selected in the Record of Decision (ROD] and because the affected environment has 
changed since preparation of those documents. The construction activities associated with the 
current design proposal would be considerably less than described in the 1999 document. In 
addition, riparian vegetation has grown since 1999 and the resulting impacts to riparian forest in 
this reach area expected to be greater than described in the 1999 EIR/EIS. Most of the impacts of 
the proposed would be due to habitat restoration actions, including: channel reconfiguration, 
installation of habitat structures, removal of exotic plant species, and slope stabilization. 

The purpose, need, and goals of the proposed Reach 12 project have not changed since the 1999 
EIR/EIS was published. Similar to the current proposal, in the 1999 EIS/EIR, Reach 12 served as a 
mitigation reach to mitigate impacts to riparian forest, SRA cover, and wetlands from construction 
of the overall Upper Guadalupe River Flood Risk Management Project. The 1999 document 
identified three project alternatives, including the No-Project Alternative, Minimize Vegetation 
Impacts Alternative, and the preferred project. The preferred project proposed to achieve flood 
protection in the Upper Guadalupe River area through channel widening, modifications of levees, 
and the construction of bypass channels. The minimize vegetation impacts alternative proposed a 
bypass channel in some reaches to provide flood protection and, therefore, minimize impacts to 
riparian vegetation. For Reach 12, the preferred project proposed levees and re-vegetation and the 
Minimize Vegetation Impacts Alternative proposed a bypass channel to reduce impacts to 
vegetation. 

The currently proposed Reach 12 design proposes to leave the channel in its current location; 
however, it would excavate existing steep slopes and high benches in some areas to create 
floodplain benches that would be inundated during bankfull flows. To the maximum extent 
practicable, native riparian vegetation would be preserved; however, in areas where excavation is 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 7 




proposed, riparian vegetation would be removed. Non-native woody vegetation with invasive 
characteristics would also be removed and generally replaced with native riparian vegetation. 
Riparian forest affected by construction would be mitigated for at the same ratio proposed in the 
1999 EIR/EIS. 

1.6 Scope of Alternatives 

As mentioned, the 1999 EIR/EIS provides alternatives to the proposed Upper Guadalupe River 
Flood Risk Management Project, including a no-action alternative. Impacts of these alternatives are 
detailed in that document. 

The design for Reach 12 in the 1999 EIR/EIS assumed continuation of the seasonal instream 
percolation ponds which had been used for many years by the SCVWD, and development of an off- 
stream facility west of the river which would include new percolation ponds as well as emergent 
aquatic and riparian forest mitigation areas. However, neither of these assumptions could be met. 
The spreader dams required for instream percolation ponds required permits from the California 
Department of Fish and Wildlife (CDFW] which were no longer granted after 1994. The offstream 
percolation and mitigation facility required a large area of land, which due to financial reasons 
could not be acquired by the SCVWD. 

Two other factors also came into play. Cessation of the seasonal instream percolation ponds 
resulted in substantial vegetation re-growth along the river, and created opportunity for planting of 
additional mitigation areas within the river's riparian corridor instead of offstream. In addition, 
increased interest in fluvial geomorphic consideration led to a geomorphic re-evaluation of the 
reach and a determination that its fluvial geomorphic conditions are suboptimal. 

Therefore, the design for Reach 12 was revised to reflect these changed conditions. The prior 
project elements were dropped and were replaced with revised creation of new floodplains, 
placement of coarse sediment, installation of woody structures in the channel for fish habitat, and 
planting of riparian forest where allowed by hydraulic constraints. 

Variations to the revised design of Reach 12 were considered during reevaluation of the proposed 
project (USACE 2014], Variations included two alternatives to the deferred floodwall were 
considered—the Widen Channel Alternative and Levee Alternative. The floodwall alternative was 
selected for the design because it provides the least environmental impact of the three alternatives 
considered. However, construction of a floodwall is uncertain at this time and any construction 
would be deferred to approximately 10 years from the preparation of this Supplemental EA and 
environmental effects of that action would be re-evaluated at that time. 

Because the 1999 EIR/EIS describes in detail the impacts of alternatives to the proposed action, 
including the no-action alternative, the scope of this Supplemental EA is limited to a discussion of 
the impacts of the proposed action. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 8 




1.7 


Unresolved Issues 


At the time of the publication of the final Supplemental EA, no unresolved issues remain. 


2.0 Proposed Action 

This section discusses the agency preferred alternative (proposed action or project]. The proposed 
action was developed to meet the objectives of providing mitigation for the overall Upper 
Guadalupe River Flood Risk Management Project and protect the adjacent percolation ponds. The 
proposed action consists of: 

• Channel modifications, including flood bench excavation, gravel augmentation, and 
installation of instream structures to improve river morphology and improve fish habitat, 

• Raising existing berms that separate the SCVWD percolation ponds from the river, 

• Constructing maintenance access roads, 

• Removal of non-native and invasive plant species, 

• Planting riparian vegetation to mitigate for loss of shaded riverine aquatic [SRA] cover in 
other river reaches, 

• Installing fencing along a portion of the SCVWD property line, 

• Maintaining plantings for a period of 4 years after construction to ensure establishment, 

• Create a connection to the recreation existing trail at the northern terminus of Blossom 
River Drive 

Hydraulic modeling of Reach 12 indicates that the downstream portion of the existing channel, as 
well as the modified channel resulting from the proposed action, would not meet the USACE risk 
and uncertainty standard for providing a 1 percent annual level of protection from floods. Meeting 
this standard would require additional flood risk reduction work beyond that included in the 
proposed action. 

Floodwall installation on the downstream part of the west bank in Reach 12 was investigated to 
address this issue. However, construction of flood risk reduction measures in upstream parts of the 
project (such as Reach 12] prior to completion of all downstream flood risk management work 
would shift flood risks from current patterns to new patterns. This could result in increased flood 
risk for certain areas (induced flooding] which is contrary to USACE policy. 

Therefore, construction of this floodwall or some alternate flood risk management measure is not 
included in the proposed action. This issue will be reconsidered as completion of the project 
approaches (expected in approximately 9-10 years], and would be addressed in appropriate 
environmental documentation at that time. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 9 




The proposed action would not require construction of this floodwall and is not dependent upon it. 
Upon implementation of the proposed action, the floodwall would remain a discretionary action for 
future consideration should all downstream flood risk management work be funded and completed. 

The Proposed Action includes berms to protect the percolation ponds from floodwaters. These 
berms would not be considered flood control levees under Corps policy. The berms would not have 
a significant effect on downstream flood risk, due to the relatively small storage space currently 
available above the water level in these ponds that would be foregone through the construction of 
these berms. Therefore, construction of these berms would not be inconsistent with deferral of 
floodwall downstream in the same reach. 

An overview of the project features are shown in Figure 3 and Error! Reference source not 
found.. Site preparation and construction activities associated with the above-mentioned project 
features are detailed in the following subsections. Vegetation removal is expected to begin in 2014. 
Other construction activities are expected to being in 2015 and are expected to be completed within 
1 year. Maintenance activities for establishment of habitat mitigation areas would persist for 4 
years post-construction. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 10 




Match Line 



Ramp 

_Temporary Ramp 

Potential Floodwall (Not Part of the Proposed Project) 
| Debris Jam 
Rootwad 
Stream Barb 

Low Flow Water Elevation Surface Level 


15-foot Buffer around Low Flow Water Level 


0 0.025 0.05 0.1 Miles 

l_i_i_i_I_i_i_i_l 


Legend 

Floodplain Cut 
Floodplain Fill 
Berm 

Gravel Augmentation 
Maintenance Road 




Figure 3. Reach 12 Proposed Project Components - Upstream 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 11 




















































Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


This page is intentionally left blank. 


Page 12 







mw 


Legend 

Project Features 

Floodplain Cut 
Floodplain Fill 
Berm 

Gravel Augmentation 
, Maintenance Road 
Ramp 

Potential Floodwall (Not Part of the Proposed Project) 
| Debris Jam 
Rootwad 
Stream Barb 




N 








Low Flow Water Elevation Surface Level 


15-foot Buffer around Low Flow Water Level 


Road alignment shown here is 
approximate. Road will be 
alighed to minimze impacts to 
existing trees 


A ; » 






K-W ' * 










Match Line 




0.1 Miles 


R a ■ 


Figure 4. Reach 12 Proposed Project Components - Downstream 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Page 14 




2.1 


Site Constraints 


The design of the proposed project was constrained by several physical, biological, and 
environmental factors. These factors were considered during the revision of the 1999 design plan. 
Constraints include: 

• Percolation ponds adjacent to the river that should be protected; 

• Existing soil characteristics which limit engineering design and future mitigation plantings; 

• Limited deep water availability for riparian plantings in the downstream portion of the 
reach 

• Very limited coarse sediment supply due to existing upstream reservoirs and urbanization; 

• Limited right of ways in some locations; 

• Existing non-native invasive species that should be removed to protect habitat functions of 
the reach; 

• Existing native vegetation to remain to the maximum extent practicable; and 

• Mercury levels of the existing on-site soil; and 

• Frequent use of the area by transients and associated risk of theft and vandalism to fixed 
irrigation equipment. 

2.2 Site Preparation 

Site preparation consists of clearing and grubbing vegetation and other debris, and diverting 
(dewatering] the reach. These activities, and subsequent construction, would be constrained by the 
need to protect existing utilities, storm drains and outfalls, and San Jose Water Company 
groundwater wells that are present in the project area, but are not to be altered during the project. 

Existing Utilities: An existing 42-inch diameter storm drain outfall on the east side (near the 
intersection of Blossom River Drive and Blossom River Way] has rock riprap protection. The riprap 
would be removed to re-grade the channel (creating a low bench for floodplain functions and 
riparian vegetation]. The rock material would be saved and re-installed in the same location 
following the required grading. The grading was designed to ensure that the existing outfalls would 
continue to function. 

An existing 36-inch storm drain outfall on the east side under Branham Lane Bridge would remain. 
The existing gabion-lined slope under the bridge would be modified to accommodate the 
maintenance road passing under the bridge and keep the exiting storm drain outfall unaltered. All 
other existing storm drain and outfall structures would remain and be protected from construction 
impacts. 

Installing Erosion Control: Erosion control materials would be installed in certain project areas to 
prevent runoff and other pollution from entering storm drains and the channel water prior to 
construction. Erosion control that would be installed during site preparation includes installation 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 15 





of silt fencing and bales around storm drains and in areas adjacent to the river. Instream 
structures, and willow and cottonwood cuttings, would provide long-term erosion control benefits. 

Clearing and Grubbing: Clearing and grubbing would occur in approximately 5 acres of the 30- 
acre project area. This process would involve removing unwanted trees, shrubs, stumps and roots 
in areas where earthwork would occur. Herbaceous plants would be removed by grading. Holes 
resulting from removal of stumps and roots would be backfilled. Areas where clearing and 
grubbing occur would be left at a grade creating flood benches at bankfull elevation. Clearing and 
grubbing would result in up to 12,300 cubic yards of grub material and 4,100 cubic yards of soil 
that would require removal from the site. This debris and rubbish would be removed from the 
entire project site and transported to a suitable site for disposal or recycling. Transport of debris 
and rubbish would be conducted in a manner that prevents spillage on streets or adjacent areas. 
Equipment required for clearing and grubbing activities include loaders, excavators, dozers, 
chippers, and transport trucks. 

Soils in portions of the reach have relatively high concentrations of mercury due to historic mining 
upstream. The San Francisco District Regional Water Quality Control Board (RWQCB) has provided 
guidance on reusing mercury-laden sediment in the project area. These requirements are 
discussed in detail later in this document (see Sections 3.3 and 3.4} and summarized here. 

Sediment with concentrations of mercury from 2.3 ppm up to 5.0 ppm [inclusive] can be reused 
within the Project boundaries at a depth equal to or greater than 2.0 feet below ground surface 
(bgs] within 20.0 feet of the low flow channel or at any depth more than 20.0 feet away from the 
low flow channel. Sediment with concentrations equal to or less than 2.3 ppm may be used at any 
location within the Project boundaries. All sediment with mercury concentration of 5.0 - 20.0 ppm 
would be used only above the 50-year flood elevation. All graded areas would be hydroseeded, and 
if within the channel would be covered with erosion control blanket. All excess material from this 
reach would be transported to a properly permitted disposal site 

Dewatering: Prior to in-channel activities (i.e., gravel augmentation and installation of instream 
structures) the surface water would be diverted around construction activities and these locations 
would be dewatered. The footprint of dewatering would be approximately 1.5 acres which would 
encompass only portions of the length of the low-flow channel. Dewatering would involve 
installation of a cofferdam upstream of construction activities, rerouting the flow downstream of in¬ 
channel activities, and pumping water out of the dewatering area as needed. Once the segment of 
the river is dewatered, trash would be removed from the river bed and transported to a suitable 
site for disposal or recycling. Dewatering would be conducted during the work windows already 
established for the Upper Guadalupe River Flood Risk Management Project—June 1 through 
October 15. Prior to construction, a dewatering plan would be prepared and submitted to the 
RWQCB and National Marine Fisheries Service (NMFS) for review and approval. The RWQCB Order 
R2-2003-0115 and the NMFS Biological Opinion allow dewatering as early as May 1 if two 
conditions are met: average water temperature exceeds 64 degrees F., and fish surveys find no 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 16 




steelhead. This provision may be utilized to start construction early if the stated conditions are 
met. 

As part of the dewatering process, a qualified fish biologist would remove all native vertebrate 
organisms in the section of river being dewatered. These would be safely transported to river 
sections upstream or downstream of the dewatered section for release. 

2.3 Removal of Non-native and Invasive Plant Species 

Some non-native and native vegetation would be removed in certain areas within the project area. 
In areas where earthwork is proposed to create flood benches, existing vegetation would be 
removed during clearing and grubbing. In other areas, non-native and invasive woody plants 
would be removed to allow for planting native species. In several areas where native vegetation 
would be preserved, removal of non-native vegetation could occur by hand to ensure the native 
vegetation is preserved. Some non-native trees would be retained where they are not invasive or 
provide important visual resources as well as some habitat value. Vegetation eradication methods 
would include: 

• Woody plants (i.e., trees, shrubs] would be cut down and stumps painted with herbicide. 

• Invasive herbaceous weeds would be sprayed with herbicides; after they are dead, the 
vegetation would be cleared and removed. Herbicide application would only be allowed 
within 20 feet of the river from June 1 through October 15, and in the overall channel until 
October 30. 

• If noxious weeds are observed during times when herbicide applications are not allowed 
per the Upper Guadalupe Project's WDR (San Francisco Bay RWQCB WDR, 2003], they 
would be removed manually or mechanically. 

Prior to construction, the vegetation proposed for preservation would be clearly marked, thereby 
ensuring that the vegetation removed around it does not cause harm. Table 1 shows the existing or 
potential non-native and invasive plants proposed for removal or control. The decision as to 
whether eradication or control would be the goal would depend on the invasiveness and 
practicality of eradication for each species. 

2.4 Channel Modification 

The purpose of the channel modifications (i.e., flood bench creation, laying back steep banks, gravel 
augmentation, and installation of instream structures] is to improve river morphology and provide 
more and better riparian habitat. These activities were designed to stabilized over-steeped slopes, 
attain better floodplain elevations, and improve the geomorphology and physical and biological 
functioning of the river. The changes would not affect the overall gradient of this reach. However, 
locally the channel profile would be adjusted via gravel placement to convert short steep riffles into 
longer, low gradient riffles and/or pool-riffle sequences. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 17 




Table 1 Non-native and Invasive Plants Proposed for 

Eradication or Control 

Common Name 

Scientific Name 

Acacia 

Acacia spp. 

Tree of heaven 

Ailanthus altissima 

Italian alder 

Alnuscordata 

Giant reed 

Arundo donax 

Yellow mustard 

Brassica campestris 

Black mustard 

Brassica nigra 

Yellow-star thistle 

Centaurea solstitialis 

Poison hemlock 

Conium maculatum 

Field bindweed 

Convolvulus arvensis 

Jubata grass 

Cortaderia jubata 

Pampas grass 

Cortaderia selloana 

Bermuda grass 

Cynodon dactylon 

Cape ivy 

Delairea odorata 

Stinkwort 

Dittrichia graveolens 

Veldt grass 

Ehrharta erecta 

Blue gum 

Eucalyptus globulus 

Ash (nonnative species] 

Fraxinus spp. 

Black walnut 

Juglans hindsii 

Rice cutgrass 

Leersia oryzoides 

Sweetgum 

Liquidamber styraciflua 

Perennial pepperweed 

Lepidium latifolium 

Japanese privet 

Ligustrum lucidum 

Olive 

Olea europaea 

Harding grass 

Phalaris aquatica 

Common reed 

Phragmites australis 

Bristly ox-tongue 

Picris echioides 

Smilo grass 

Piptatherum miliaceum 

London plane tree 

(including hybrids with native sycamore) 

Plantanus x acerifolia 

Holly oak 

Quercus ilex 

Wild radish 

Raphanus sativus 

Italian buckthorn 

Rhamnus alternus 

Castor bean 

Ricinus communis 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 18 







































Table 1 Non-native and Invasive Plants Proposed for 

Eradication or Control 

Common Name 

Scientific Name 

Black locust 

Robinia pseudoacacia 

Himalayan blackberry 

Rubus armeniacus 

Weeping willow 

Salix babylonica 

Corkscrew willow 

Salix matsudana 

Red sesbania 

Sesbania punicea 

Tamarisk 

Tamarix spp. 

Elm 

Ulmusspp. 

Greater periwinkle 

Vinca major 


Grading adjacent banks to create flood benches would not require dewatering the channel; 
however, dewatering would be required during gravel augmentation and installation of instream 
structures. It is anticipated that dewatering would only occur during one construction year (2015]; 
however, should instream activities not be completed, additional dewatering may be required the 
next construction year [2016], 

2.4.1 Flood Bench Creation 

Approximately 1.2 acres of flood benches would be created along the banks of portions of the river 
by excavating steep banks adjacent to the channel to bankfull elevation (Error! Reference source 
not found.]. The flood benches were designed to be inundated only during bankfull or higher flood 
events; during lower-flow events, waters would be contained within the river's bankfull channel. 
Prior to excavation, the channel would be protected from sedimentation and other construction 
activities by silt fence, coir log, and hay bales. 

Areas within 20 feet of the low-flow channel that contain sediments with mercury concentrations 
greater than 2.3 ppm would be over-excavated by 2 feet. It is anticipated that approximately 1,500 
cubic yards of soil would be excavated to accommodate the 2-foot cover requirement. Clean soil 
(approximately 1,500 cubic yards] would be imported to the site to backfill over-excavated areas. 
Approximately 150 trucks would be required to import clean sediment to the site. Over excavation 
would only occur when the river is dewatered. 

The total estimated volume of clearing and grubbing excavation for the reach is approximately 
15,600 cubic yards of material. This includes 1,500 cubic yards of over-excavation in selected 
areas. The estimated volume of fill is approximately 12,361 cubic yards. All sediment proposed for 
excavation is suitable for use within various portions of the project. Therefore, approximately 
12,361 cubic yards of sediment excavated would be reused somewhere on the project site in 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 19 















accordance with the RWQCBs reuse requirements for sediment containing mercury (see Table 14 in 
Section 4.3], Sediment suitable for construction would be immediately transported to fill areas 
(e.g., areas where berms would be raised] or stockpiled for future use. The remaining 6,322 cubic 
yards of sediment would be transported to an approved disposal site (currently identified as Kirby 
Canyon Landfill or Guadalupe Landfill], Approximately 632 truck loads would be required to 
transport this sediment to disposal sites. 

When excavation is complete, coconut fiber erosion control blanks would be installed and disturbed 
areas would be replanted with native riparian vegetation or hydroseeded. Section 2.8 provides a 
discussion on replanting. 

2.4.2 Gravel Augmentation 

Reach 12 was historically a braided channel with a high volume of gravel in the stream bed. The 
upstream half of the reach was used as a gravel quarry starting in the 1930s and the river was 
realigned in the 1970s. This portion of the reach has very little aquatic habitat variability and the 
channel is degraded. At the approximate halfway point of the reach, the channel bends. 
Downstream from this point, the low-flow channel morphology provides better habitat than the 
upstream portion. Approximately 1,300 feet upstream of this reach is the Alamitos Drop Structure, 
which helps create Lake Almaden a short distance upstream of the drop structure. The backwater 
upstream of the drop structure and the deep lake traps most of the gravel transported by 
Guadalupe Creek and Alamitos Creek, respectively. Therefore, reaches immediately downstream of 
the drop structure are starved of coarse sediment, and Reach 12 is a priority reach to add large 
volumes of gravel that can slowly migrate to the downstream reaches. 

The overall approach for gravel augmentation in this reach is to 1] establish long-term gravel 
augmentation locations at the upstream end of the reach in a location where hydraulic conditions 
are favorable for downstream distribution during high flow events, 2] redistribute elevation drop in 
two long flat pools by creating a more natural pool-riffle sequence in pools, and 3] supplement 
gravel in the proposed realignment location. 

The gravel augmentation is intended to be hydraulically subtle and would not change the flood 
conveyance, require over-excavation, or result in short-term alterations of riparian vegetation or 
low flow water surface elevation. This augmentation would be integrated with the proposed 
installation of large instream structures discussed in Section 2.4.3. However, as gravel is routed 
downstream, local deposition may result in establishment of gravel bars and may cause local 
changes in downstream reaches. Changes may include gravel deposition along the channel margins 
(bars] in existing riparian vegetation and small changes in riffle elevations. 

Gravel used for augmentation would be free of fine sediment. Fine bed load sand supply is likely to 
be lower in Reach 12 due to partial trapping behind Alamitos Drop Structure. As a result, bars that 
develop would likely be less prone to riparian encroachment for the first few years following 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 20 




construction. Over time, riparian encroachment on the bars may occur if high flows do not scour 
and redeposit gravel bars and if fine sediment from upstream sources infiltrates the bars. 

Three sites are identified for gravel augmentation in Reach 12 (Figure 5). Note that these sites are 
generally located on this figure; actual placement would only be within the low-flow channel. Site 1 
is located from station 1019+00 to 1001+00, site 2 is from 997+00 to 981+50, and site 3 is located 
immediate upstream of Branham Land Bridge at station 962+30 to 961+50. Site 1, particularly 
upstream, is the highest priority of all sites because it is the furthest upstream augmentation site 
and the most gravel starved. This site has convenient access and can accommodate large volumes 
of gravel. The downstream portion of site 1 and all of site 2 are considered medium priority; they 
have smaller volume capacities and would require access development to access them. Currently, 
site 3 is the lowest priority; however, once the floodway widths in downstream reaches 
(particularly 11C] are increased and resulting residence times increased, gravel augmentation 
priority would increase. There is an eroding gravel/sand bank at the near station 963+00 
(upstream end of gravel augmentation site 3], which provides small gravels to the channel for 
downstream transport and deposition. This area may naturally supplement augmented gravel as 
the bank continues to erode. 

The total footprint of gravel augmentation activities is approximately 1 acre. It is anticipated that 
approximately 6,080 cubic yards of gravel would be required to facilitate gravel augmentation. 
Gravel would be trucked to the site and stored at staging areas until ready for use. Transport of the 
gravel to the site would require approximately 608 truck loads. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 21 





Figure 5. Reach 12 Generalized Sites for Gravel Augmentation 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 22 









Site 1: Gravel augmentation in site 1 has two components. Component 1 involves redistributing 
the slope by filling the long pool, augmenting the pool tail at Station 1016+00, and creating a new 
riffle crest located at station 1018+00 (downstream side of Blossom Hill Road Bridge] (Figure 6, 
Figure 7, and Figure 8], The elevation of the new riffle crest at station 1018+00 would be slightly 
lower than the elevation of the riffle crest at station 1020+00, causing a low flow backwater up to 
station 1020+00. This area would gently slope down in elevation over the next 200 feet to station 
1016+00 (Figure 7 and Figure 8], The gravel would be placed entirely within the low flow channel 
with no exposed bars. 

Component 2 involves gravel augmentation to create a more natural channel morphology in the 
long flat pool between stations 1009+25 and 1040+50 (Figure 8 and Figure 9], An alternative bar 
sequence and new riffle is proposed in the existing long flat pool. The new riffle would increase the 
low flow water surface elevation by approximately 0.5 to 1 foot, backing water into the upstream 
riffle and thereby redistributing this elevation drop through the long flat pool. This minor increase 
in low flow water surface elevation is not expected to impact flood conveyance or existing riparian 
vegetation along the channel margin. Table 2 provides details of the implementation features, 
stations where they would be located, area of impact, depth, and volume of gravel proposed. 


Table 2 Site 1 Proposed Gravel Augmentation and Channel 

Modification 

Implementation 

Feature 

Upstream 

Station 

Downstream 

Station 

Area 

(square feet) 

Depth 

(feet) 

Volume 
(cubic yard) 

Pool tail 
augmentation 

1018+00 

1016+30 

10,680 

3 

1,190 

East bank bar 
augmentation 

1009+25 

1006+30 

4,220 

4.5 

700 

Riffle augmentation 

1007+50 

1006+00 

2,800 

3 

410 

West bank bar 
augmentation 

1007+00 

1004+50 

5,640 

4.5 

940 

Total Gravel Volume 

3,240 

Source: USACE 2014. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 23 


















Figure 6. Site 1 Proposed Gravel Augmentation from Stations 1018+50 to 
1016+40 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Figure 7. Site 1 Proposed Gravel Augmentation from Stations 1009+00 to 
1004+30 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 25 






















Cross Section 1016+75 



»*4 

»n 

190 

1 M 


1*4 

’*3 

tao 

179 

179 

17* 

in 

m 

IU 

<N 

s« 

Ml 


8 

9 


Longitudinal Profile 



100l>«90 <004+00 *004+90 1000+00 *000+90 *000+00 1000+90 1007+00 (007+90 1000+00 1000+90 1000+00 (000+90 1010+00 1010+90 1011-400 


Longitudinal Profile 



LEGEND 

Profile and/or Cross Section View 


- Existing Ground ' /// Recommended Grovel Fill — Bor 

_ Design Ground - HEC—RAS Q“1.5 yr Approx. Water Surface 

lL7~LT~Ll Recommended Gravel Fill — Riffle 


Figure 8. Site 1 Thalweg Profile and Cross Sections from Stations 1018+50 to 1044+30 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 26 







































Figure 9. Site 1 - Gravel Augmentation Site from Stations 1018+00 to 1004+00 

(Looking downstream at backwater pool. Proposed conversion to a low gradient riffle) 


Site 2: Site 2 has two construction components. Component one is to redistribute the slope by 
filling in another long flat pool, thereby creating a more natural pool-riffle sequence with alternate 
bars (Figure 10, Figure 11, and Figure 12). The first pool is located immediately off Highway 85 
Bridge and extends from stations 996+40 to 991+70 (Figure 11). Similar to site 1, the elevation 
drop at the upstream riffle would be redistributed into a new pool-riffle sequence downstream, 
lowering the gradient of upstream riffle and creating new low gradient riffles and bars. The 
elevation of the upstream riffle crest (station 996+40) would not be altered and gravel 
augmentation would begin at the riffle crest and extend downstream (Figure 10). 

The second component is to construct the low flow channel from station 985+90 to 983+60 using 
gravel augmentation (Figure 10 and Figure 12). The channel in this area is in good geomorphic 
condition, the existing west bank point bar consists of stable gravels and small cobbles and the 
gradient through this reach is well distributed as natural pools and riffles. Because there is a 
naturally formed bar here, and gravel from upstream augmentation would likely deposit here. 

Table 3 shows the gravel augmentation proposed for site 2, including the feature the gravel 
augmentation is intended to create, as well as the up- and downstream station locations of each 
feature, the footprint (area), gravel depth, and volume of gravel fill required to create each feature. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 27 










Table 3 Site 2 Proposed Gravel Augmentation and Channel 

Modification 

Implementation 

Feature 

Upstream 

Station 

Downstream 

Station 

Area 

(square feet) 

Depth 

(feet) 

Volume 
(cubic yard) 

Riffle augmentation 

996+40 

995+50 

3,080 

4 

456 

West bank bar 
augmentation 

996+40 

993+00 

5,250 

6 

1,167 

Riffle augmentation 

994+00 

993+00 

2,530 

2.5 

234 

East bank bar 
augmentation 

994+00 

991+90 

4,340 

4 

643 

Riffle augmentation 

985+90 

985+50 

360 

1 

12 

West bank bar 
augmentation 

985+90 

984+60 

810 

2 

60 

Riffle augmentation 

985+00 

974+60 

330 

1 

12 

East bank bar 
augmentation 

985+00 

983+60 

1,240 

2 

92 

Riffle augmentation 

983+90 

983+60 

270 

1 

10 

West bank bar 
augmentation 

983+90 

982+90 

640 

2 

47 

Riffle augmentation 

983+25 

982+90 

420 

2 

23 

East bank bar 
augmentation 

983+00 

982+00 

690 

2 

51 

Total Gravel Volume 

2,807 

Source: USACE 2014. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 28 


























Figure 10. Site 2 Proposed Gravel Augmentations and Stockpile Site from Stations 
996+50 to 991+50 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 29 
























Figure 11. Site 2 Proposed Gravel Augmentation and Gravel Stockpile from 
Station 986+00 to 982+00 


Upper Guadalupe Flood Control Project, Reach 12 

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United States Army Corps of Engineers 


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Upper Guadalupe Flood Control Project, Reach 12 

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United States Army Corps of Engineers 


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Site 3: Gravel augmentation in site 3 involves supplementing the pool tail at station 962+00 with 
gravel up to the riffle crest on the upstream side of Branham Lane Bridge, adding an average depth 
of 2.5 feet of gravel (Figure 13]. This gravel also prevents erosion and undercutting of the Branham 
Lane box culvert. Table 4 provides the details of gravel augmentation for site 3. 


Table 4 Site 3 Proposed Gravel Augmentation and Channel 

Modification 

Implementation 

Feature 

Upstream 

Station 

Downstream 

Station 

Area 

(square feet) 

Depth 

(feet) 

Volume 

(cubic yard) 

Pool tail 
augmentation 

963+00 

961+00 

1,540 

2.5 

140 

Total Gravel Volume 

140 

Source: USACE 2014. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 32 















142 

>40 g 
8 

1S4 < 

? 

i»4 i 

a 

in 

190 


Plonform View_ 

Contour (5ft) — Existing Ground 
Contour (1ft) - Existing Ground 
BBS] Recommended Gravel Fill - Riffle 
Recommended Gravel Fill — Bar 
8,2 Profile ond/or Cross Section 

Low Flow Woter Edge _ 


Station (Ft) 

LEGEND 

Alignment or Cross Section View_ 

- - Existing Ground 

P~U-W-1 Recommended Gravel Fill -Riffle 

- HEC—RAS Q=1.5 yr Approx. Woter 

Surface 


Figure 13. Site 3 Proposed Gravel Augmentation and Thalweg Profile from 
Stations 963+00 to 961+00 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 33 























2.4.3 


Installation of Instream Structures 


Instream woody structures would be installed in the channel to provide increased low-flow channel 
sinuosity and stability, SRA cover, and enhanced fish habitat. In addition to gravel augmentation, 
there are four types of instream structures: debris jams, log toe structures, rootwad bank 
structures, and undercut bank structures. 

Installation of the instream structures would require localized excavation. The undercut bank 
structures would require approximately 77 cubic yards of excavation and the rootwads would 
require approximately 120 cubic yards (8 cubic yards each]. The structures would be anchored 
with cables to the river bank at the low-flow level. Excavation for and installation of instream 
structures would only occur when the reach is dewatered. 

The locations of instream structures were determined based on the desired function of individual 
structures. The entire reach was surveyed for adequacy of instream structure placement. Table 5 
summarizes where these structures would be placed and the desired hydraulic, geomorphic and 
ecological benefits of the structures. 


Table 5 Instream Structures, Type, Location and Purpose 

Instream 

Structure 

Number 

Type 

Location 

Purpose 

Debris jam 

9 

Instream flow 

redirection 

technique 

Along edges of 
low-flow channel 

in the widest sub¬ 
reaches 

Increase hydraulic complexity by 
inducing deposition on upstream 
end of structure and locally 
inducing scour to establish pools 
on downstream end. 

Provide suitable material for the 

establishment of new riffles 

downstream of the structure. 
Provide refugia near bank. 

Provide instream cover. 

Provide bank stabilization. 

Decrease low-flow width. 

Stream 

barb 

structure 

9 

Instream flow 

redirection 

technique 

Toe of steep banks 

Redirects flow from the toe of the 

stream bank to reduce the 
potential for scour and bank 
failure upstream of the structure. 
Increases scour downstream to 
create a deep pool. 

Rootwad 

15 

Structural bank 

Upstream and 

Encourages undercut banks and 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 5 Instream Structures, Type, Location and Purpose 

Instream 

Structure 

Number 

Type 

Location 

Purpose 

bank 

structure 


protection 
techniques and 
instream flow 

redirection 

technique 

downstream of 
gravel 

augmentation 

cover for fish habitat. 

Ties into shoaling effect of 
upstream logs and gravel bar. 

Undercut 

bank 

structure 

7 

Habitat 

structure 

Left bank between 

Stations 976+00 

and 977+00 

Provides instream cover with 

discontinuous undercut bank. 
Provides refugia near bank. 

Source: USACE 2014. 


2.5 Raising Existing Berms 

Existing berms would be raised to protect the SCVWD's percolation ponds from sediment and 
pollution in river water during large flood events. Some portions of the existing berm that 
separates the river from three adjacent percolation ponds are not high enough to contain the 100- 
year flood flow within the river and these areas would be overtopped during flood events of this 
size and somewhat small. These berms would be raised between the river and the existing 
percolation pond No. 2 on the west side and No. 3 on the east side. The purpose of the raised berm 
is to meet the USACE criteria for containing the 100-year flood flow within the channel and not 
allow the water to overtop the raised berms and flow to the ponds. It is intended to protect the 
percolation ponds from suspended solids and hazardous materials conveyed by the river during 
large storm events. The existing overbank areas around the percolation ponds already provide the 
100-year level of protection to surrounding urban development with an adequate margin of safety. 

Approximately 1,220 linear feet of berms would be raised on the west bank and 1,560 linear feet 
would be raised along the east bank, for a total of 2,780 linear feet. The top of berm elevation 
would range between 180 and 190 feet on the west side and 178 and 181 on the east side with an 
approximately 1 foot of freeboard. Raising the berms would require excavation of approximately 
250 cubic yards of sediment and 8,805 cubic yards of fill. Fill material would come from suitable 
(less than 20 ppm of mercury) onsite material excavated in the project area. The approximate 
limits of where the berms would be raised (up- and downstream stations and elevations) and 
excavation and fill requirements and other construction aspects are shown in Table 6. 


Upper Guadalupe Flood Control Project, Reach 12 

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Table 6 

Berm Raising Locations, Lengths, and Elevation Data 


Berm 

Location 

Upstream - 
Downstream 

Stations 

Linear 

Feet 

Excavation 

(cubic yards) 

Fill 

(cubic 

yards ) 1 

Top of 
Berm 

Elevation 

(feet) 

(downstream 
- upstream) 

Water 

Surface 

(feet) 

(downstream 
- upstream) 

Freeboard 

(feet) 

(downstream 
- upstream) 

West 

bank 

1001+50 - 

996+00 

1,220 

186 

2,689 

180.00 - 

180.80 

178.78- 

17960 

1.10 - 1.21 

East 

bank 

1002+40 - 

987+00 

1,560 

64 

6,116 

178.70 - 

180.70 

177.69 - 

179.60 

1.01 - 1.10 

TOTAL 

2,780 

250 

8,805 

- 

Source: USACE DDR, 2012 


The raised berms would have an 18-foot-wide crest to accommodate maintenance access roads on 
top, except in areas where existing site conditions require a narrower crest. In these areas, the 
minimum crest width would be 12 feet (see Section 2.6 for information on maintenance access 
roads]. The top of the berm would have a cross slope of 2 percent towards each side. Fill slopes 
would be 2 horizontal to 1 vertical [2H:1V] for the percolation pond side and 2.5H:1V for the river 
side. 

The raised berm crest would provide a 1-foot freeboard plus the required camber [overbuild]. 
Geotechnical studies have recommended overbuild to accommodate the anticipated settlement of 
the raised berm fill. The required overbuild is 2-3 inches on the east side and 1-5 inches on the 
west side; both sides would require up to 5 feet of fill. Material to raise berms would come from 
clean sediment excavated from the banks (sediment with mercury concentrations less than 20 
PPm]. 

The raised berm alignment would generally follow the alignment of the existing trail and 
maintenance road. The alignment would be defined by work point, bearing, distance, stations and 
curvature properties in the same manner as the maintenance access road. The alignment would be 
located such that the minimum road width can be accommodated without encroaching into the 
existing percolation ponds. In the vicinity of the Highway 85 overcrossings, the alignment would be 
designed so that there would be no filling adjacent to the existing concrete columns supporting the 
overcrossings. 

Prior to construction of each raised berm, an inspection trench would be excavated along the length 
of the berm to locate any shallow buried pipes or roots, and also serve to improve the bond 
between the existing material and the fill material for the raised berm. The total length for the 


Upper Guadalupe Flood Control Project, Reach 12 

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inspection trenches would be 1,740 feet, and they would be 2.5 feet deep and 8 feet wide. Each 
trench would start and end where the raised berm is more than 2 feet in height. Approximately 
1,300 cubic yards of sediment would be excavated to construct the trenches. After inspection of the 
trench determines that there are no buried pipes or roots under the proposed berm, the trench 
would be filled with compacted soil as part of construction of the berm. If buried pipes or roots are 
found, they would be removed or relocated prior to construction of the berm. This excavated 
material would either be reused to backfill the trench. 

To monitor the elevation of the raised berms, settlement monuments would be installed. The 
location of the monuments would be at approximately 500-foot intervals or as recommended by a 
geotechnical engineer. 

2.6 Maintenance Road and Ramp Construction 

Maintenance access roads are proposed along each side of the river along the top of the banks. 
Approximately 8,500 linear feet of road would be located on top of the existing berms, once they 
are raised, and 600 feet of new maintenance road would be constructed, for a total of 9,100 linear 
feet of road. The maintenance road would provide access for personnel and equipment to the 
stream channel for inspection and maintenance of this reach. The approximate limits of the roads 
are shown in Table 7. 


Table 7 

Maintenance Access Road Limits 

Access Road 

Location 

Upstream Station 

Downstream Station 

West Bank 

1008+50 

962+50 

East Bank 1 

1002+50 

984+00 

East Bank 2 

979+50 

961+50 


The west side maintenance roads would be located on the top of the raised berm along most of its 
length. At the upstream end, it would connect to an existing gravel-surfaced trail. This trail is 
located on top of the existing berm that separates the river from percolation pond No. 1 and No. 2. 
The downstream end would be at the paved parking lot near Branham Lane on the west bank slope. 

The east side maintenance roads would not be continuous and the road would be constructed in 
two portions due to the very narrow width of part of the top of bank which prohibits construction 
of an access road. The upstream portion (east bank 1] would start at a connection to the existing 
asphalt trail along the east side of the river adjacent to Blossom River Drive. It would continue 
downstream to the bend in the river where it would stop approximate 200 feet after the bend. The 
downstream portion (east bank 2] would start approximately 700 feet downstream of the bend in 


Upper Guadalupe Flood Control Project, Reach 12 

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the river and continue downstream where it would split in two. At the split, one road would ramp 
up towards the existing access gate at Branham Land and the other would ramp down towards the 
river and lead to an underpass beneath Branham Lane Bridge. A portion of the road approximately 
600 feet in length and located 300 feet upstream of Branham Lane Bridge is within San Jose Water 
Company property; the San Jose Water Company has already provided permission for construction 
of this portion of the project. The SCVWD has acquired two additional easements to construct 
portions of the maintenance road on the west bank. 

The roads would be 18 feet wide, except where the existing site conditions require a narrower road 
width. The locations where an 18-foot-wide road cannot be accommodated would be a minimum of 
12 feet wide. On the existing berm between the river and the percolation pond, the crest width is 
narrow and therefore a 12-foot width would be used for the access road and this would also be the 
crest width for the raised berm. At the downstream portion of the east access road, where it would 
be within the San Jose Water Company property, the road would only be 12 feet wide as this is what 
San Jose Water Company will allow on their property. 

The horizontal and vertical alignments would generally follow the alignment and grade of the 
existing trail and maintenance road. The vertical alignment would have a maximum 5 percent 
grade. The alignment would be located such that the minimum road width as discussed below can 
be accommodated without encroaching into the existing percolation pounds and also minimize 
impact on the existing channel. 

The road would have cross slope of 2 percent towards each side where the road is located between 
the river and the percolation pond. Where the road is located along the river's natural top of bank, 
the 2 percent cross-slope would be sloping down towards the river. 

There would be a ramp on the east side to provide continuous access underneath the existing 
Branham Lane Bridge. Site constraints at this location involves an existing 36-inch diameter storm 
drain outfall, limited vertical clearance as imposed by the bridge deck soffit elevation, and existing 
gabion slope protection for the bridge abutment. The vertical clearance for this ramp would be 
10.75 feet and the width of the ramp would be 12 feet. 

The access roads would have a minimum 6 inches of aggregate surfacing over compacted fill (raised 
berm fill] or they would be scarified and compacted sub-grade. Approximately 1,530 cubic yards of 
aggregate fill would be required for the maintenance roads (1,400 for the west road and 1,130 for 
the east]. Approximately 230 trucks loads would be required to transport gravel to the project site. 
If necessary, gravel would be stockpiled at an existing staging area on the west bank just south of 
the bend (station 990+00], 

Three access ramps would be constructed to provide inspection and maintenance access to the 
river's low-flow channel, and for future gravel augmentation, if necessary. The purpose of each 
access ramp is discussed below. 


Upper Guadalupe Flood Control Project, Reach 12 

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Access Ramp E4: This ramp would be on the east side and would provide access to the upstream 
end of the gravel augmentation area at this location. It would serve as access for future placement 
of material as needed for gravel augmentation. It would also serves as access for SCVWD 
maintenance staff for removal of any debris on the river and for vegetation maintenance work. 

Access Ramp W3: This ramp is on the west side and is an existing ramp that would be resurfaced. 
This ramp is located immediately downstream of the existing Caltrans storm drain outfall. The 
existing outfall is a concrete structure. The ramp currently provides access to the outfall for 
maintenance operations by Caltrans. It would also serve as access for SCVWD maintenance staff for 
removal of debris in the river that comes with the flow from the outfall and also to facilitate 
maintenance of vegetation. 

Access Ramp E2: This ramp would be on the east side and would provide access for SCVWD 
maintenance staff to remove debris and facilitate vegetation maintenance work. It is the only 
access ramp connecting the east maintenance road from Branham Lane to the thalweg of the river. 
The east maintenance road is discontinuous and it ends near this ramp. Without this ramp, there 
would be no access to the thalweg for removal of debris. 

In total, approximately 530 linear feet of ramp would be constructed. These ramps would be 12 
feet wide with a 4-inch thick gravel surfacing and have a 10-15 percent grade. They would have a 
2-percent cross slope in one direction (sloping down towards the river side] and would be located 
strategically to avoid existing vegetation. Approximately 74 cubic yards of aggregate surface would 
be imported to the site in 7 truck loads. Table 8 and Figure 3 and Figure 4 show the location of the 
proposed ramps and the volume of aggregate surface material required. 


Table 8 Proposed Channel Maintenance Access Ramps 

Access Road 

Location 

Upstream Station 

Downstream Station 

Aggregate Surface 
(cubic yards) 

East Bank [E4] 

1010+00 

1008+00 

29 

West Bank (W3) 1 

992+50 

990+60 

27 

East Bank [E2] 

976+40 

975+00 

18 

1 The east bank ramp between 992+50 and 990+60 already exists, but would be reconstructed as part of the proposed 
project. 


Upper Guadalupe Flood Control Project, Reach 12 

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2.8 


Planting Vegetation 


The primary objective of Reach 12 is to maximize the area of riparian forest and length of SRA 
cover. These increased habitats would be mitigation for the impacts of the proposed Reach 12 
project and for other reaches of the overall Upper Guadalupe River Flood Risk Management Project. 

The vast majority of existing woody vegetation would be preserved. In areas where woody 
vegetation would be removed, it would generally be replaced with native woody vegetation. New 
woody vegetation would be planted in areas which are not constrained by hydraulic and other 
limitations. The combination of existing vegetation, newly planted vegetation, and flood bench 
construction would increase riparian forest habitat areas and complexity. Based on the USFWS 
habitat evaluation, the habitat value of the reach would increase above current values. In addition, 
to achieve the habitat goals of this project, some existing stream banks would be graded to create 
elevations suitable for establishment and long-term viability of riparian plantings. The plant 
palette for each planting zone was developed using the constraints of the post-project hydraulic 
capacity limitations and soil moisture conditions (USACE 2014}. It is anticipated that plant 
installation would occur starting in late fall 2015 and continuing to early winter in 2016. Figures 
22 and 23 (Section 3.5} show the locations of proposed vegetation plantings. 

The Reach 12 planting design was based on the results of the hydraulic and geomorphic analyses 
conducted to support the design process (USACE 2014}. Several factors were considered when 
determining the locations and types of plantings, including the river morphology of the reach— 
both before and after implementation of flood risk management improvements—soil conditions, 
depth to groundwater, slope, hydraulic capacity, planting zone location relative to floodplain 
surfaces and bank location, and characteristics of reference sites (in Reach 12} with similar 
hydrogeomorphic and soil conditions. Based on these factors, as well as the density of the existing 
riparian forest in Reach 12, it was determined that riparian forest would be restored where feasible 
on the following landforms: 

• Natural bank and terrace surfaces capable of supporting riparian vegetation but currently 
lacking woody plant cover, 

• Graded bench-cuts, 

• A portion of the areas where non-native woody vegetation would be removed, and 

• Other surfaces created for flood conveyance or mitigation purposes. 

Shaded riverine aquatic (SRA} cover plantings are a subset of the riparian forest plant palette and 
would be primarily located in the streamside and lower floodplain planting zones. Shaded riverine 
aquatic cover mitigation plantings are those that are located within 15 feet of a stream bank. This 
habitat would be planted on both the east and west stream banks where space is available. Plant 
material installed would be provided from container stock, cuttings, acorns, and seeds (Table 9 and 
Table 10}. All plant material would be obtained from parent material in Reach 12, other reaches of 
the Upper Guadalupe River, the nearby Guadalupe Creek mitigation site, and other locations within 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 40 




Guadalupe River watershed. The one exception would be limited California native plantings in the 
special upland planting zone. 

The planting design developed for the proposed action includes seven planting zones. A brief 
description of these zones is provided below. Figure 14 depicts the general structure of the 
streamside, upper floodplain, and lower floodplain planting zones; instream structure and upland 
planting zones are not shown. Table 9 and Table 10 present the plant palettes for each of the 
planting zones. 

• Streamside Planting Zone. This zone would be planted along selected areas of the stream 
bank to provide SRA cover. The streamside planting zone would be located on lower 
floodplain surfaces adjacent to or in the vicinity of the channel margin. Vegetation would be 
supported by seasonal precipitation, seasonal floodplain inundation, surface water and 
groundwater. Shaded riverine aquatic cover would contribute to moderating water 
temperatures, providing instream cover (e.g., exposed roots, low-hanging branches, and 
scour holes] and increased organic matter input. The plant palette for this zone includes 
native riparian trees, shrubs, and vines (Table 9], 

• Instream Structure Planting Zone. This zone consists of the large woody debris structures 
that would be placed in specific locations to enhance aquatic habitat. The structures would 
be located on the channel margin and would extend into the channel. Vegetation would 
primarily be supported by seasonal precipitation, seasonal floodplain inundation and 
surface water. The plant palette for this zone is primarily composed of native willows 
(Table 10). 

• Lower Floodplain Seeding and Planting Zone. This zone would be planted on lower 
floodplain surface that would be seasonally inundated. The distance of this zone from the 
channel varies by location. The floodplain elevations would also be variable based on 
existing or graded conditions; therefore, the extent and depth of inundation would vary 
based on water surface elevations associated with each rainfall event. Vegetation would be 
supported by seasonal precipitation, seasonal floodplain inundation, surface water and 
groundwater. The species selected for this zone would have growth forms and planting 
densities that are more open and less restrictive to conveyance of high water events but 
would still provide multistory habitat zones to benefit terrestrial species. Because of post¬ 
project hydraulic capacity limitations and soil moisture conditions, the plant palette for this 
zone is primarily composed plants that are more drought tolerant (Table 9). 

• Upper Floodplain Seeding and Planting Zone. This zone would be planted on upper 
floodplain surfaces and low channel bank elevations. This zone would only be inundated 
during high flow events. The distance of this zone from the channel varies by location. The 
floodplain elevations would also be variable based on existing or graded conditions; 
therefore, the extent and depth of inundation would vary based on water surface elevations 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 41 




associated with each rainfall event. Vegetation would be supported by seasonal 
precipitation, occasional floodplain inundation and groundwater, if available. The species 
selected for this zone would have a growth form that is less restrictive to high water events 
but would still provide multistory habitat zones to benefit terrestrial species. Because of 
post-project hydraulic capacity limitations and soil moisture conditions, the plant palette 
for this zone is primarily composed of native trees, shrubs, vines, and herbs that are 
drought tolerant (Table 9], 

• Upland Planting Zone. This zone would be planted on upper banks and on the high terrace, 
beyond the top of channel bank. This zone would not be inundated, with the possible 
exception of the flood protect design surface elevation. The distance of this zone from the 
channel varies by location. Vegetation would be supported by seasonal precipitation and 
groundwater, if available. The plant palette for this zone is primarily composed of native 
trees, shrubs, and herbs found in relatively xeric riparian areas, such as valley oak (Table 9). 
Because these areas are not intended to convey water efficiently, planting density would 
only be limited by natural water availability. 

• Special Upland Planting Zone. This zone would be confined to limited areas behind the 
houses along Tonino Drive. Tree species would be similar to the upland planting zone, but 
understory plants would be selected for greater fire resistance and shrub density would be 
relatively low to reduce fire risk. Perennial grasses would not be planted, but temporary 
hydroseed would be used as elsewhere. Understory species would be native to lowland 
portions of California but not necessarily to the local area. Species planted which are native 
to the Guadalupe River watershed would only be from local genotypes. This area can be 
thought of as a transition zone between the native riparian corridor and the exotic 
vegetation around the houses, and would mitigate loss of exotic vegetation in the project. 

• Hydroseed Zone. This zone would be limited to hydroseeding newly constructed berm 
slopes and other disturbed sites for erosion control. Because of post-project hydraulic 
capacity limitations or engineering concerns, this zone can only be seeded with grasses. No 
woody plants or vines would be planted in this zone. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Upper Guadalupe Flood Control Project, Reach 12 

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Table 9 

Reach 12 Planting Zone Palette 


Growth Form 

Species 

Propagule 

Scientific Name 

Common Name 

Type 

Streamside Planting Palette 

Tree 

Alnus rhombifolia 

Populus fremontii 

Quercus lobata 

Salix laevigata 

Salix lasiolepis 

White alder 

Fremont cottonwood 

Valley oak 

Red willow 

Arroyo willow 

Container 

Cutting 

Acorn 

Cutting 

Cutting 

Shrub 

Baccharis salicifolia 

Rosa californica 

Rubus ursinus 

Salix exigua 

Mule fat 

California wild rose 

California blackberry 

Narrow-leaved willow 

Container 

Container 

Container 

Cutting 

Vine 

Clematis ligusticifolia 

Virgin's bower 

Container 

Lower Floodplain Seeding and Planting Zone Palette 

Tree 

Populus fremontii 

Quercus lobata 

Salix laevigata 

Salix lasiolepis 

Fremont cottonwood 

Valley oak 

Red willow 

Arroyo willow 

Cutting 

Acorn 

Cutting 

Cutting 

Shrub 

Salix exigua 

Narrow-leaved willow 

Cutting 

Herbaceous 

Artemisia douglasiana 
Heterotheca oregona var. 
scaberrima 

Mugwort 

Oregon false goldenaster 

Container 

Container 


Leymus triticoides 

Marah fabaceus 

Creeping wildrye 

California man-root 

Container 

Container 

Upper Floodplain Seeding and Planting Zone Palette 

Tree 

Aescuius californica 

Quercus agrifolia 

Quercus lobata 

California buckeye 

Coast live oak 

Valley oak 

Large seed 

Acorn 

Acorn 

Herbaceous 

Artemisia douglasiana 
Heterotheca oregona var. 
scaberrima 

Mugwort 

Oregon false goldenaster 

Container 

Container 


Leymus triticoides 

Creeping wildrye 

Container 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 9 

Reach 12 Planting Zone Palette 


Growth Form 

Species 

Propagule 

Scientific Name 

Common Name 

Type 


Mar ah fabaceus 

California man-root 

Container 

Upland Planting Zone Palette 


Aesculus californica 

California buckeye 

Large seed 

Tree 

Quercus agrifolia 

Coast live oak 

Acorn 


Quercus lobata 

Valley oak 

Acorn 

Shrub 

Artemisia californica 

California sagebrush 

Container 

Herbaceous 

Bromus carinatus 

California brome 

Container 

Stipa pulchra 

Purple needlegrass 

Container 

Special Upland Planting Zone 

Tree 

Quercus agrifolia 

Coast live oak 

Acorn 


Quercuslobata 

Valley oak 

Acorn 


Sambucus caerulea 

Blue elderberry 

Container 


Mimulus aurantiacus 

Bush monkeyflower 

Container 

Shrub 

Rhamnus californica 

California coffeeberry 

Container 


Ribes viburnifolium 

Catalina currant 

Container 


Trichostema lanatum 

Wooly blue curls 

Container 

Herbaceous 

Achillea millefolium 

Epilobium canum 

Yarrow 

California fuschia 

Container 

Container 

Source: USACE 2014. 


Table 10 

Reach 12 In-Stream Planting Palette 


Structure 

Growth 

Species 

Propagule 

Type 

Form 

Scientific Name 

Common Name 

Type 


Tree 

Salix lasiolepis 

Arroyo willow 

Cutting 

Debris jam 

Shrub 

Baccharis salicifolia 
Salix exigua 

Mule fat 

Narrow-leaved willow 

Container 

Cutting 

Rootwad bank 

Tree 

Salix laevigata 

Red willow 

Cutting 


Upper Guadalupe Flood Control Project, Reach 12 
Environmental Assessment 

United States Army Corps of Engineers Page 45 




































Table 10 Reach 12 In-Stream Planting Palette 


Structure 

Type 

Growth 

Form 

Species 

Propagule 

Type 

Scientific Name 

Common Name 

Shrub 

Baccharis salicifolia 
Salix exigua 

Mule fat 

Narrow-leaved willow 

Container 

Cutting 

Stream barb 

Tree 

Salix lasiolepis 

Arroyo willow 

Cutting 

Shrub 

Salix exigua 

Narrow-leaved willow 

Cutting 

Undercut 

bank 

Tree 

Salix laevigata 

Red willow 

Cutting 

Shrub 

Baccharis salicifolia 
Salix exigua 

Mule fat 

Narrow-leaved willow 

Container 

Cutting 


Source: USACE 2014. 


2.9 Installation of Fencing 

Approximately 3,000 linear feet of permanent chain link fence would be installed in portions of the 
reach. An additional but unknown amount of temporary fencing would be installed around the 
construction trailer and storage areas. This may amount to 500-1,000 feet of additional fencing. 

Temporary Fence: Temporary protective fencing would be installed between construction 
activities and riparian vegetation proposed for preservation where needed to protect the 
vegetation. 

Permanent Chain Link Fence: Permanent chain link fence would be installed along the SCVWD 
property line on or near the top of the west bank. The fence would begin at approximately station 
966+25 and run south along the top of bank to station 995+50. At approximately 987+75, the fence 
would turn southeast for approximately 300 feet before turning south again. The fence would be 
approximately 6 feet high with posts installed every 10 feet or less. 

2.10 Plant and Reach Maintenance 

Plant and reach maintenance would occur for a period of 4 years following planting. Maintenance 
would include: 


• Weed control, 

• Corrective pruning, 

• Hand watering, 

• Replacement planting, 

• Maintaining mulch and plant protection cages, 


Upper Guadalupe Flood Control Project, Reach 12 

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• Maintaining all project signs, 

• Maintaining erosion control blankets, and 

• Policing the project area. 

Plant watering would generally occur between March and October of each year, but may be 
modified based on seasonal conditions. All mitigation plants would be hand-watered using a low- 
pressure standard garden hose connected to a watering truck. The watering truck would use the 
constructed maintenance roads to access the plantings. Watering would be phased out over time 
to enable the plants to become self-sufficient. 

Performance standards and success criteria of all plantings would conform to the 1999 Mitigation 
Monitoring Plan (MMP; SCVWD and USACE 1999], RWQCB Order R2-2003-0115, and the 2005 
Supplemental Biological Opinion unless approved changes are agreed upon. In general, these 
documents provide that riparian forest mitigation acres would need to be at a 2:1 ratio to riparian 
forest losses, and emergent aquatic wetland habitat would need to be mitigated at a 1:1 ratio to 
losses. This supplemental EA also includes the riparian forest compensation ratio of 1:1.85 from 
the 2007 congressionally-authorized Upper Guadalupe River Flood Risk Management Project Local 
Preferred Plan (LLP], 

Since development of the 1999 MMP flood control improvements and habitat mitigation have been 
implemented on other reaches of the Upper Guadalupe River. Each of these projects has been 
monitored following implementation. Monitoring required includes measuring the survival and 
health and vigor, natural recruitment, cover, non-native species, and wildlife use of riparian forest 
and SRA cover. Additionally, undercut bank is monitored to determine the amount of undercut (at 
least 10 centimeters] and fish passage improvements are inspected to determine if they are 
impeding fish passage. 

The Adaptive Management Team (ATM] for the Guadalupe River composed of representatives of 
the USACE, SCVWD, federal and state agencies and others may be reevaluating and revising the 
Upper Guadalupe MMP in spring 2014. The AMT's decisions would apply to Reach 12 as well. As a 
result, specification information on the monitoring program is not available at this time. Following 
completion of the Reach 12 project, the USACE and SCVWD would develop an operations and 
maintenance manual that would identify the maintenance requirements for the reach. This manual 
would identify specific requirements developed by the AMT. 

2.11 Summary of Construction Activities 

This section provides a summary of the major construction activities, construction equipment, and 
timing necessary to construct the proposed project. Table 11 provides a summary of the details. 


Upper Guadalupe Flood Control Project, Reach 12 

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Table 11 Summary of Reach 12 Construction Activities a 


Construc¬ 
tion Activity 

Footprint 

(acre, linear 
feet, etc.) 

Excava¬ 
tion and 
Clearing 
(cubic 
yards) 

Total 

Fill 

(cubic 

yards) 

Reuse of 

Excavated 

Material 

for Fill 

Gravel or 
Aggregate 
Fill 

(cubic 

yards) 

Truck 

Loads 

Required to 
Import 
Material 

Truck 

Loads 
Required 
to Dispose 
of Material 

Construction 

Equipment 

Construction 

Duration 

(months) 

Construc¬ 
tion Years 

Clearing and 
grubbing 

5 acres 

12,300 b 

(grub 

material) 

4,100 

(soil) 

- 

- 

- 

- 

1,640 

Loader, 

excavator, 

dozer, 

chippers 

2 

2015 

Dewatering 
segments of 
the river 

1.5 acres 

cumulative for 

reach 

- 

- 

- 


- 

- 

Pump, 

pipes/hoses, 

sandbags, 

plastic 

sheeting 

2-4 weeks 
dewatered per 
location. 2 days 
to dewater, 1 day 
to re-water per 

location. 

2015 

Gravel 

augmentation 

1 acre 

- 

- 

- 

6,080 

608 

- 

Dozer, grader, 
water truck 

3 

2015 

Flood bench 

1.2 acres 

7,900 

52 

Yes 

- 

5 

632 d 

Excavator, 
dozer, crane, 
grader, roller, 
soil stabilizer, 

water truck 

7 

2015 

Flood bench 

backfill 

within 20 feet 

of low flow 

channel 

0.45 acre 

1,500 

l,500 c 

No 

- 

150 

Installation of 

instream 

structures 

15 rootwads 

9 debris jams 

9 stream barbs 

7 undercut banks 

198 

198 c 

Yes 

- 

20 

Excavator, 

crane 

4 

2015 

Raising berms 

2,780 

linear feet 

250 

8,805 

Yes 

- 

- 

Excavator, 
dozer, grader, 
roller, soil 

1.5 

2015 

Inspection 

1,740 linear feet 

1,288 

1,288 

Yes 

- 

- 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 48 


























Table 11 Summary of Reach 12 Construction Activities a 

Construc¬ 
tion Activity 

Footprint 

(acre, linear 
feet, etc.) 

Excava¬ 
tion and 
Clearing 
(cubic 
yards) 

Total 

Fill 

(cubic 

yards) 

Reuse of 

Excavated 

Material 

for Fill 

Gravel or 
Aggregate 
Fill 

(cubic 

yards) 

Truck 

Loads 

Required to 
Import 
Material 

Truck 

Loads 
Required 
to Dispose 
of Material 

Construction 

Equipment 

Construction 

Duration 

(months) 

Construc¬ 
tion Years 

trenches 
(trenches will be 
backfilled) 








stabilizer, 

water truck 



Maintenance 

roads 

9,100 linear feet 
(8,500 on existing 
berms; 600 new) 

280 

- 

Yes 

2,530 

253 

Ramps 

530 

linear feet 

15 

516 

Yes 

74 

7 

Riparian 

forest 

removal 

0.48 acres 

- 

- 

- 

- 

- 

- 

- 

- 

- 

Riparian 
habitat re¬ 
vegetation 

2.22 acres 

- 

- 

- 

- 

- 

- 

Loader 

2.5 

2015 

SRA cover 

removal 

387 linear feet 

- 

- 

- 

- 

- 

- 

- 

- 

- 

SRA cover 
replacement 

658 linear feet 

- 

- 

- 

- 

- 

- 

- 

- 

- 

Fencing 

3,000 

Linear feet 

- 

- 

- 

- 

- 

- 

Loader 

1 

2014 

TOTAL 

29,283 

12,361 

10,661 

8,684 

1,043 

2,272 

- 

21 

2014- 

2015 

Total truck loads = 3,315 

Notes: 

a Plant and site maintenance is not included in this table. Maintenance would continue for approximately 8 months each year for 4 years. 
b It is anticipated that approximately 12,300 cubic yards of debris would be removed from clearing and grubbing the project site. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 49 



























Table 11 Summary of Reach 12 Construction Activities a 


Construc¬ 
tion Activity 

Footprint 

(acre, linear 
feet, etc.) 

Excava¬ 
tion and 
Clearing 
(cubic 
yards) 

Total 

Fill 

(cubic 

yards) 

Reuse of 

Excavated 

Material 

for Fill 

Gravel or 
Aggregate 
Fill 

(cubic 

yards) 

Truck 

Loads 

Required to 
Import 
Material 

Truck 

Loads 
Required 
to Dispose 
of Material 

Construction 

Equipment 

Construction 

Duration 

(months) 

Construc¬ 
tion Years 


c Clean sediment would be imported to backfill over excavated areas within 20 feet of the low flow channel. 

d Sediment sampling and analysis shows that all excavated sediment has mercury concentrations less than 20 ppm and could be used somewhere within the project area. Approximately 16,983 cubic yards of 
sediment is proposed for excavation and the fill requirement is 10,661 cubic yards; therefore, 6,322 cubic yards are in excess and would be disposed of at an approved facility, 
e Includes cleared and grubbed vegetation and other debris. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 50 


















3.0 Existing Conditions and Consequences of the Proposed Action 

This section discusses the existing conditions of the Reach 12 project area and effects of the 
proposed action. The 1999 EIR/EIS detail impacts of the overall Upper Guadalupe River Flood Risk 
Management Project alternatives, including the no-action alternative. Impacts resulting from the 
no-action alternative have not changed since the publication of the 1999 EIR/EIS. The impacts 
resulting from implementation of the alternatives to the proposed action, including the no action 
alternative, are provided in the original 1999 EIR/EIS and this document only discloses the impacts 
of the proposed design changes that are not disclosed in the 1999 document. Resources that were 
adequately addressed in the EIS/EIR include: geology, soils, and seismicity (soil quality is 
addressed in this EA, however]; mineral resources; energy consumption or generation, 
environmental justice, growth inducing impacts, and hazardous and toxic materials. The reader is 
referred to the 1999 EIS/EIR for details about potential impacts to these resources. 

Table 12 provides an overview of the environmental resources analyzed in this supplemental EA, 
the potential impacts of the propose project on the respective resource, and avoidance, 
minimization and mitigation measures to ensure impacts are reduced to less than significant. 


Upper Guadalupe Flood Control Project, Reach 12 

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United States Army Corps of Engineers 


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Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 

Flood Risk 
Management 

Impact H&H-l: Result in significant flooding 
downstream of the project area. 

Less than significant 

None 

Flows, Currents, 

and Circulation 

Impact H&H-2: Result in significant adverse 
effects on flows, currents, and circulation. It 

Less than significant 

during construction 

Beneficial following 
construction 

None 

Ground Water 

(Aquifer 

recharge) 

Impact H&H-3: Result in substantial depletion 
of groundwater or interfere with groundwater 
recharge. 

Less than significant 

during construction. 

None 

Soil 

Quality 

Impact SQ-1: Degrade sediment quality during 
construction or after construction. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure SQ-1: 

Comply with the San Francisco Bay RWQCB’s 
requirements for reuse of mercury-laden sediment 
(see Table 14). 

Avoidance and Minimization Measure SQ-2: 

Utilize erosion control measures to ensure that 
mercury-laden sediment does not erode into the 
adjacent river. 

Avoidance and Minimization Measure SQ-3: 

Utilize best management practices to ensure that 
mercury-laden sediment does not erode into the 

Impact SQ-2: Expose water or biological 
receptors to concentrations of mercury that 
would violate standards 

Less than significant 

with Avoidance and 

Minimization Measures 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 




adjacent river. 

Avoidance and Minimization Measure SQ-4: 

All stockpiling of sediment shall be conducted in 
such a manner that prevents sediment from 
eroding into adjacent areas or streams. 

Avoidance and Minimization Measure SQ-5: 

Dispose of mercury-laden sediment at approved 
upland facilities. 

Water Quality 

Impact WQ-1: Violate any water quality 
standard or waste discharge standard set by the 
RWQCB or substantially degrade water quality. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure WQ-1: 

Comply with erosion control measures identified in 
the Construction General National Pollution 
Discharge Elimination System (NPDES) permit. 

Avoidance and Minimization Measure WQ-3: 

Comply with the mercury and diazinon TMDLs for 
Guadalupe River and ensure that concentrations of 
CWA 303(d) constituents listed for Guadalupe River 
(mercury, diazinon, and trash) are not increased. 

Avoidance and Minimization Measure WQ-1: 

Comply with erosion control measures identified in 

Impact WQ-2: Increase the concentration of 
any CWA 303(d) substance identified for 
Guadalupe River (mercury, diazinon, or trash) or 
violate the river’s TMDLs (mercury and 
diazinon). 

Less than significant 

with Avoidance and 

Minimization Measures 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Impact WQ-3: Substantially contribute to 
runoff water which would exceed the capacity of 
existing or planned stormwater drainage 
systems. 

Less than significant 

with Avoidance and 

Minimization Measures 

the Construction General National Pollution 
Discharge Elimination System (NPDES) permit. 

Biological 

Environment 

Impact BIO-1: Result in a substantial loss of 
riparian forest or SRA cover that would not 
reestablish within 10 years following 
construction. 

Less than significant 

with Avoidance, 
Minimization, and 
Mitigation Measures 

Avoidance and Minimization Measure BIO-1: 

Vegetation not proposed for removal would be 
protected during construction. 

Mitigation Measure BIO-2: Replant vegetation 
according to the planting designs for the project. 

Avoidance and Minimization Measure BIO-3: 

Update and revise the 1999 MMP. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 54 











Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Impact BIO-2: Result in permanent loss of 
wetlands or other waters of the United States. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BIO-3: 

Update and revise the 1999 MMP 

Impact BIO-3: Result in fish and wildlife 
avoiding the project area following 
establishment of riparian forest and SRA cover. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BIO-3: 

Update and revise the 1999 MMP 3 

Impact BIO-4: Result in take of listed species 
that could not be mitigated. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BI0-4: 

Monitor and relocate native fish during dewatering 

activities. 

Impact BIO-5: Result in take of protected birds 
or their nests. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure BIO-5: 

Conduct bird surveys prior to and during 

construction. 

Air Quality 

Impact AQ-1: Estimated emissions exceed 
General Conformity de minimis thresholds. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure AQ-1: 

Utilize Tier-4 off-road equipment. 

Impact AQ-2: Estimated emissions exceed 
applicable BAAQMD construction emissions 
thresholds. 

Less than significant 

with Avoidance and 

Minimization Measures 

Historic and 

Cultural 

Resources 

Impact HIST-1: Adversely affect a resource that 
is listed or has the potential to be listed on the 
National Register. 

None 

None 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 55 
















Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 

Noise 

Impact NOISE-1: Expose sensitive receptors to 
nuisance noise (i.e., nuisance noise within 500 
feet of residential uses or 200feet of commercial 
or office uses). 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure NOISE- 

1: Limit construction hours 

Avoidance and Minimization Measure NOISE- 

21 Implement best management practices 

Recreation 

Impact REC-1: Temporary closure of a portion 
of the Guadalupe River Recreational Trail 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure REC-1: 

Implement detour around the closed section of trail 

Impact REC-2: Degrade the condition of the 
existing paved recreation trail 

Less than significant 

with Avoidance and 

Minimization Measures 

Mitigation Measure REC-2: Repair and/or re¬ 
pave trail to existing condition after construction 

Transportation 
and Traffic 

Impact TT-1: Substantially interfere with 
surrounding traffic which would result in major 
delays. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure TT-1: 

Prepare and implement a traffic control plan. 

Avoidance and Minimization Measure TT-3: 

Minimize interference with existing traffic. 

Impact TT-2: Damage roads or highways. 

Less than significant 

with Mitigation Measures 

Mitigation Measure TT-4: Repair and 
rehabilitate roads damaged by construction 
vehicles 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Impact TT-3: Result in injury or harm to other 
drivers, pedestrians, bikers, or others using any 
form of transportation in the project area. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure TT-1: 

Prepare and implement a traffic control plan. 

Avoidance and Minimization Measure TT-2: 

Utilize traffic control safety measures. 

Land Use 

Classification 

Impact LU-1: Conflict with the adopted General 
Plan designations, land uses, or physical 
arrangement of the community. 

Less than significant 

None 

Aesthetics 

Impact VR-1: Losses of vegetative cover in 
limited portions of the river channel and the west 
bank due to construction activity and selective 
removal of non-native trees and shrubs. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure VIS-1: 

Retain native vegetation to the maximum extent 
practicable. 

Mitigation Measure BIO-2: Replant vegetation 
according to the planting designs for the project. 

Impact VR-2: Temporary views of construction 
activities and materials. 

Less than significant 

None 

Impact VR-3: New berms along the percolation 
ponds. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure VIS-1: 

Retain native vegetation to the maximum extent 
practicable. 

Mitigation Measure VIS-3: Hydroseed areas 
where vegetation would be removed. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 12 Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 


Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Impact VR-4: Loss of trees behind houses on the 
east bank, downstream portion of the reach. 

Less than significant 

Avoidance and Minimization Measure VIS-2: 

Retain non-invasive non-native native trees in this 
area to the extent practicable. 

Public Utilities, 
Facilities, and 

Services. 

Impact PUS-1: Potential interference with 

Police and Fire protection services. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Minimization Measure PUS-1: 

Notify police and fire protection services regarding 
construction and implement site security patrol. 

Impact PUS-2: Potential interference with 
utility service. 

Less than significant 

with Avoidance and 

Minimization Measures 

Mitigation Measure PUS-2: Identify and 
coordinate relocation or protection of utilities. 

Avoidance and Minimization Measure PUS-3: 

Avoid placement of trees in locations that could 
interfere with utilities. 

Public Health 
and Safety 

Impact PHS-1: Potential public safety impacts 
due to unauthorized entry to the construction 
area or the reach after construction is complete. 

Less than significant 

with Avoidance and 

Minimization Measures 

Avoidance and Mitigation Measure PHS-1: 

Provide warning signs, install fencing and 
barricades, and implement site security patrol at 
construction site. 

Avoidance and Mitigation Measure PHS-2: 

Install permanent access control measures post¬ 
construction. 

Impact PHS-2: Construction Hazards to 

Less than significant 

with Avoidance and 

Avoidance and Mitigation Measure PHS-3: 

Identify truck routes and construction zones prior 


Upper Guadalupe Flood Control Project, Reach 12 
Environmental Assessment 

United States Army Corps of Engineers Page 58 














Table 12 

Potential Effects and Proposed Avoidance, Minimization, and Mitigation Measures 

Environmental 

Resource 

Summary of Potential Impact(s) 

Impact Analysis 

Mitigation 


Vehicles and Pedestrians. 

Minimization Measures 

to project commencement. 




Avoidance and Mitigation Measure PHS-4: 

Notify residents of construction schedule and 
proposed traffic detours. 


Impact PHS-3: Displacement of Homeless 

Persons Occupying the Reach. 

Less than significant 

None 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 59 











3.1 


Hydrology and Hydraulics 


The Guadalupe River watershed drains approximately 171 square miles. The headwaters drain the 
eastern Santa Cruz Mountains near the summit of Loma Prieta in heavily forested unincorporated 
county land with pockets of low-density residential developments. The Guadalupe River begins at 
the confluence of Alamitos and Guadalupe creeks. From here it flows north approximately 14 miles 
until it discharges to the South San Francisco Bay. The approximate 19-mile-long river flows 
through the cities of San Jose and Santa Clara. Its three main tributaries Ross, Canoas, and Los 
Gatos Creek all join the mainstem of the Guadalupe River. 

Flow and sediment supply to the Upper Guadalupe River are affected by the operation of several 
reservoirs in the upper watershed, including Almaden Reservoir on Alamitos Creek, Calero 
Reservoir Arroyo on Calero Creek, and Guadalupe Reservoir on Guadalupe Creek. Constructed in 
the 1930s and 1950s, these dams and reservoirs have a combined storage capacity of 15,360 
acre-feet and regulate runoff from 24.8 square miles of the upper watershed, or 47 percent of the 
drainage area to Reach 12. In 1997, new reservoir operating strategies were implemented to 
reduce flood damage while minimizing impact to water supply. These three reservoirs are kept 
below their maximum capacity due to seismic stability concerns and this limits their flood-control 
capacity. 

In addition, Lake Almaden, a former gravel pit through which Alamitos Creek flows, removes all 
coarse sediment from that creek, further diminishing the downstream supply of this sediment. 
During the dry season, dashboards on top of the Alamitos Drop Structure back water up through 
this lake and provide a small amount of storage and increased groundwater recharge. During the 
wet season, the dashboards are removed and the drop structure no longer backs water up to the 
lake. 

The presence of these dams in the watershed affects channel-forming dow magnitude and channel 
function by: (1] reducing dood peaks, especially for smaller, more frequent doods and thus 
reducing the magnitude of the channel-forming discharge, and (2] eliminating coarse sediment 
supply from the upper watershed to the project reaches. In addition to the dams and reservoirs, the 
Alamitos Drop Structure may also reduce sediment supply to the river. This structure, located 
1,300 feet upstream of Reach 12, serves primarily as a point of dow diversion to nearby percolation 
ponds. The drop structure and the backwater it creates upstream (including Lake Almaden] have 
minimal storage capacity and are too small to affect dood magnitude, but they likely trap nearly all 
coarse sediment and a portion of dne sediment in transport from upstream reaches, and likely 
prevents coarse sediment routing to the downstream reaches. Sediment from upstream of the drop 
structure is removed annually and is not returned to the river due to its mercury content. 

Urbanization also affects both dow and sediment supply to the river. Urbanization increases the 
area of impervious surface area in the watershed and, thus, decreases infiltration and increases 
runoff volume and magnitude (Dunne and Leopold 1978], As the impervious area in the watershed 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 60 




increases to 10-20 percent, runoff volume doubles, at 35-50 percent impervious area runoff 
increases threefold, and at 75-100 percent impervious area runoff increases fivefold 
(Paul and Meyer 2001], In the Guadalupe River watershed, the magnitude of urban development 
and relative area of the watershed covered by impermeable surfaces increases in a downstream 
direction. In the upper elevations (i.e., upstream of reservoirs], the watershed is free of urban 
development with virtually no impervious surface. Moving downstream into Santa Clara Valley, 
impervious surface area increases to 5-24 percent in the middle watershed (i.e., from the dams 
downstream to the Alamitos Creek/Guadalupe Creek confluence] and to 48-60 percent from the 
Alamitos Creek/Guadalupe Creek confluence to the downstream end of the river. Urbanization also 
reduces sediment supply in the long-term (after the land-clearing and construction phases are 
complete]. In response to increased flow and reduced sediment supply, urban low flow channels 
typically incise and widen. In such incised or widening channels, bankfull depth often does not 
correspond to the tops of banks or other indicators that are likely artifacts of past hydrologic and 
sediment supply conditions. 

3.1.1 Flood Risk Management 

The overall purpose of the Upper Guadalupe River Flood Control Project is to reduce the flood risk 
along the river from the one-percent flood and lesser floods. The Reach 12 channel generally has 
enough capacity to contain these floods within its channel and the percolation pond area adjacent 
to the creek; therefore, construction of the proposed action is not for flood risk management. This 
reach is intended to be a mitigation reach to compensate for the impacts to riparian forest and SRA 
cover from the overall Upper Guadalupe River project. Changes to Reach 12 following construction 
of the proposed action would not change this reach’s capacity to convey floods. However, flood 
benches, channel modifications, and placement of in-stream structures would provide better 
habitat for fish. 

The lower portion of Reach 12 has enough capacity to contain the one-percent flood, but does not 
have enough capacity to provide an adequate margin of safety under USACE policies. However, 
improving flood protection in this upstream reach would relocate some degree of flood risk to 
downstream areas and would be in violation of USACE policy. Therefore, while a conceptual 
floodwall has been designed for the lower portion of the reach, it cannot be constructed until all 
downstream flood risk management construction has been completed. At that time, the floodwall 
could be constructed if it is still deemed to be necessary. However, neither the current proposed 
action nor proposed downstream reaches of the Upper Guadalupe River Flood Risk Management 
Project would require construction of this floodwall or create a need or commitment to do so. 
Therefore, this floodwall is a separable action which will be evaluated further at the conclusion of 
project construction. 

The Proposed Action includes berms to protect the percolation ponds from floodwaters. These 
berms would not be considered flood control levees under Corps policy. The berms would not have 
a significant effect on downstream flood risk, due to the relatively small storage space currently 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 61 




available above the water level in these ponds that would be foregone through the construction of 
these berms. Therefore, construction of these berms is not inconsistent with deferral of floodwall 
downstream in the same reach. 

Significance Criteria: The project would have a significant effect on the environment if it would 
result in significant increase in flood risk downstream or in the adjacent areas. 

3.1.1.1 Potential Impacts and Mitigation 

Reach 12 has adequate capacity to convey flood flows and this portion of the overall Upper 
Guadalupe River Flood Risk Management Project is not intended to increase flow conveyance 
capacity or enhance flood protection to adjacent urban areas. As such, potential downstream 
flooding is not expected to result from construction of the proposed project. 

Impact H&H-l: Result in significant flooding downstream of the project area. Based on the above 
assessment, potential for downstream or adjacent flooding resulting from the proposed Reach 12 
project is expected to be less than significant. No mitigation is required. 

3.1.2 Flow, Currents, and Circulation 

Flows, currents, and drainage in Reach 12 vary. Water in the upstream portion of the reach, 
upstream of the bend, flows very slowly and tends to create large, slow flowing pools that can 
become stagnant. Downstream of the bend, water flows more quickly through riffles and smaller 
pools. The current design of the proposed project is intended to change the geomorphology of the 
river such that water throughout the river flows more similarly to the downstream portion of the 
reach. The project proposes to augment gravel in some areas creating additional riffles and fill in 
large, stagnant pools and install instream structures to stabilize the river bed and allow water to 
flow, rather than collect in pools. 

Significance Criteria: The project would have significant effects on river flows, currents, or 
circulation that would adversely affect overall flows, currents, or circulation of the Upper 
Guadalupe River. 

3.1.2.1 Potential Impacts and Mitigation 

Dewatering Reach 12 would have a temporary and local effect to the reach as water is removed 
from the channel. The water would be returned to the river downstream, thereby offsetting 
impacts to the Upper Guadalupe River. Following construction, water in Reach 12 would flow in 
riffles through smaller pools, which would improve in-water fish and wildlife habitat in the reach. 
Over time, some coarse sediment would move downstream into lower reaches, creating some of the 
same benefits in those reaches. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 62 




Impact H&H-2: Result in significant adverse effects on flows, currents, and circulation. It is 
expected that impacts to flows, currents, and circulation during construction would be less than 
significant Following construction, the river morphology would be somewhat more natural. This 
would result in a beneficial effect on the Upper Guadalupe River. No mitigation is required. 

3.1.3 Ground Water (Aquifer Recharge) 

The Upper Guadalupe River project is located in the approximate 240 square mile Santa Clara 
subbasin, which is part of the Santa Clara Valley groundwater basin. The subbasin is bounded by 
the Diablo Range to the east and Santa Cruz Mountains to the east (DWR 2004). The subbasin is 
approximately is divided into two areas, the forebay area where groundwater occurs in a single 
unconfined aquifer, and a confined area consisting of two aquifer zones—an upper and lower 
zone—separated by a regional aquitard. The forebay area is generally located at the base of the 
mountain range to the east, south, and west of the Santa Clara Valley. The confined aquifer is 
located in the central and northern portion of the valley. Reach 12 is located in the forebay region 
(USACE and SCVWD 1999a). 

Beneficial uses of the Santa Clara Valley groundwater basin include municipal and domestic water 
supply, industrial service, and agricultural water supply. The forebay is the primary recharge area 
for the entire groundwater basin. Natural recharge occurs as infiltration from streams flowing from 
the mountain ranges to the basin and from direct percolation of precipitation that falls on the basin 
floor (DWR 2004). The SCVWD also artificially recharges groundwater through its recharge 
program. Upstream or imported water is released to in-stream and off-stream facilities to recharge 
groundwater resources (USACE and SCVWD, 1999a). The percolation ponds No. 1, No. 2, and No. 3 
adjacent to Reach 12 are part of the SCVWD's groundwater recharge program. 

Significance Criteria: The Reach 12 project could a have a significant effect on groundwater 
resources if it resulted in substantial depletion of groundwater resources or interfered with 
groundwater recharge. 

3.1.3.1 Potential Impacts and Mitigation 

As mentioned, Reach 12 is located in the forebay region where natural groundwater recharge 
occurs. During year 2 (and possibly year 3 of construction), portions of Reach 12 would be 
dewatered between June 1 and October 15 (4.5 months) to place instream structures and 
hydraulically connect the excavated flood benches with the river channel. Water would be re¬ 
routed around sections of river as needed for construction and released downstream. Dewatering 
the reach has the potential to temporarily lower the water table in the surrounding area. Any 
lowering of the water table would be temporary, occurring in the immediate vicinity of Reach 12. 
Water released downstream would still be located in the forebay region and would resume 
percolating into the groundwater. In addition, the percolation ponds adjacent to the reach would 
continue to recharge the surrounding groundwater such that any lowering of the water table would 
be negligible. 


Upper Guadalupe Flood Control Project, Reach 12 

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Impact H&H-3: Result in substantial depletion of groundwater or interfere with groundwater 
recharge. Impacts to groundwater recharge are expected to be less than significant. No mitigation 
is required. 

3.2 Geology, Soils, and Seismicity 

This section summarizes the existing geology, soils, and seismicity of the project area and the 
potential effects of the proposed action on these resources. With respect to soils, this section is 
limited to the physical effects of the project on soils (e.g., the potential for slope instability and 
failure]. Sediment in the project area are known to contain elevated levels of mercury and the 
project proposes to excavate and either reuse or dispose of the mercury-laden sediment. Existing 
conditions and potential impacts related to mercury-laden sediment are discussed in Section 3.3— 
Soil Quality. 

Existing geology, soils, and seismicity in the project area have not changed since the 1999 EIR/EIS. 
Reach 12 is still situated in the general vicinity of several major regional faults zones, including the 
San Andreas Fault Zone to the west and the Hayward and Calaveras Fault Zone to the East. The 
soils in the Guadalupe River watershed have not changed and Reach 12 soils are still comprised of 
two soil associations: Sunnyvale-Castro-Clear Lake, Clear Lake-Campbell, and Yolo (USDA 1968, as 
cited in the 1999 EIR/EIS], As described in the 1999 EIR/EIS, these soil associations generally refer 
to the upper 60 inches of material. Soils in Reach 12 are located in the Sunnyvale Castro-Clear Lake 
and Yolo associations. The Sunnyvale-Castro-Clear Lake Association [SCCA] consists of poorly- 
drained, calcareous silty-clay soil and calcareous clay subsoils. It has very low permeability, high 
runoff rates, low percolation rates, high shrink-swell potential, and a moderate erosion potential. 
The Yolo Association consists of well-drained, coarsely textured silty loam soils and loam subsoils. 
This association has high percolation rates, low runoff rates, low shrink-swell capacity, and low 
erosion potential (USACE and SCVWD 1999a], 

The 1999 EIR/EIS, discusses the potential effects of the proposed project on geology and soils, as 
well as the potential for seismic activity to adversely affect the project components. Specifically, the 
document discusses the potential for: 1] the proposed project to expose people or structures to 
major geological hazards; 2] earthquake activity to adversely affect the project components—e.g., 
stream bank erosion or failure may result from land sliding or liquefaction-induced lateral 
spreading following an earthquake; 3] the potential for geology and soils to be adversely affected by 
slope instability or other components of the project. 

Because the baseline conditions of soils, geology and seismicity have not changed in the project 
area and the potential effects of the project on these resources have not changed, potential impacts 
to these resources are not further discussed in this document. The original 1999 EIR/EIS provides 
sufficient assessment of the impacts to geology, soils and seismicity and the reader is directed to 
Section 4.1 of the 1999 EIR/EIS for further discussion of these resources. 


Upper Guadalupe Flood Control Project, Reach 12 

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3.3 


Soil Quality 


In 2012, Reach 12 sediment was sampled and analyzed to evaluate the suitability of reusing 
material as fill within the reach. The results of the sampling and analysis indicate that the primary 
concern regarding sediment reuse in the project area is mercury. The Guadalupe River watershed 
is in the general vicinity of the New Almaden mines. Located 4.5 miles upstream of Reach 12, the 
mines were mining mercury from 1847 to 1976. As a result of the mining and processing activities 
at New Almaden, mercury-laden soils were transported downstream within the Guadalupe River 
watershed and are found throughout Reach 12. Details of the sediment sampling methods and 
locations are provided in the sediment sampling and analysis report (Appendix A]. The results of 
the analysis are summarized below. 

Physical and chemical analysis was performed on all composite (6 samples] and individual (16 
samples] sediment samples. Sediment samples were chemically analyzed for mercury only and 
physically analyzed for total solids, total organic carbon and grain size. Gravel and sand were the 
predominant grain types in the sediment sampled. Grain size ranged from approximately 13-66 
percent gravel and 87-34 percent sand. Total organic carbon ranged from about 0.16-1.39 percent 
and total solid content ranged from 81-98 percent. 

The mercury content of sediment samples were screened against the San Francisco Bay RWQCB's 
environmental screening levels for residential and commercial/industrial use scenarios where 
sediment is less than 3 meters below grade (San Francisco Bay RWQCB 2013, as cited in USACE 
2013], The screening levels are the same regardless of whether groundwater use occurs in this 
area. The RWQCB's environmental screening levels for residential and commercial/industrial use 
are 6.7 and 10.0 milligrams per kilogram (mg/kg], respectively. Results indicate that in general, the 
samples from Reach 12 had higher levels of mercury than samples taken in the downstream 
reaches of the Upper Guadalupe River. Of the 22 samples, 12 met the RWQCB's environmental 
screening levels for residential mercury concentrations and 10 did not. Of the samples that did not 
meet the RWQCB’s environmental screening level, three exceeded the residential screening level 
(6.7 mg/kg] and 7 exceeded the commercial/industrial screening level (10.0 mg/kg]. Two of the 
samples had concentrations of mercury greater than 15 mg/kg, which represents the highest 
concentrations in the project area. Table 13 and Figure 15 summarize the results of the sampling 
and analysis. 


Upper Guadalupe Flood Control Project, Reach 12 

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Table 13 Upper Guadalupe River Reach 12 Sediment Sampling and Analysis Results 


Sample 

Sample Type 

Grain Size (%) 

Total Organic 

Total 

Mercury c 2 - 3 

Gravel 

Sand 

Carbon (%) 

Solids (%) 

(mg/kg) 

UGR-R12-2012-1-1 

Individual 

28.1 

71.0 

1.39 

91.6 

0.9 

UGR-R12-2012-1-2 

Individual 

22.2 

77.8 

0.42 

95.7 

14.2 

UGR-R12-2012-1-3 

Individual 

43.3 

56.7 

0.50 

89.9 

6.8 

UGR-R12-2012-1-4 

Individual 

27.1 

72.9 

0.83 

89.9 

11.6 

UGR-R12-2012-1-5 

Individual 

59.5 

40.5 

0.16 

90.8 

0.4 

UGR-R12-2012-1-6 

Individual 

- 

- 

- 

98.3 

3.03 

UGR-R12-2012-1 

Composite 

49.6 

50.4 

0.77 

91.3 

3.60 

UGR-R12-2012-1Z 

Z-layer composite 

43.1 

56.9 

0.86 

91.2 

13.5 

UGR-R12-2012-2-1 

Individual 

87.2 

12.8 

0.24 

97.5 

1.49 

UGR-R12-2012-2-2 

Individual 

42.8 

57.2 

0.61 

97.8 

13.7 

UGR-R12-2012-2-3 

Individual 

20.9 

79.1 

0.84 

92.0 

4.1 

UGR-R12-2012-2-4 

Individual 

15.5 

83.5 

0.60 

90.9 

18.8 

UGR-R12-2012-2-5 

Individual 

3.4 

96.6 

0.70 

89.0 

0.6 

UGR-R12-2012-2-6 

Individual 

43.9 

56.1 

0.42 

90.9 

10.2 

UGR-R12-2012-2 

Composite 

66.4 

33.6 

0.73 

94.0 

6.6 

UGR-R12-2012-2Z 

Z-layer composite 

17.8 

82.2 

0.89 

90.0 

4.5 

UGR-R12-2012-3-1 

Individual 

46.9 

53.1 

0.42 

93.5 

9.1 

UGR-R12-2012-3-2 

Individual 

51.3 

48.7 

0.17 

87.3 

3.4 

UGR-R12-2012-3-3 

Individual 

57.9 

42.1 

0.26 

88.5 

6.1 

UGR-R12-2012-3-4 

Individual 

13.0 

87.0 

0.85 

93.2 

17.2 

UGR-R12-2012-3 

Individual 

50.5 

49.5 

0.40 

88.6 

3.7 

UGR-R12-2012-3Z 

Individual 

44.6 

55.4 

0.54 

81.2 

7.5 


Notes: 

1 Green indicates sample above the San Francisco Bay RWQCB environmental screening level for residential use (6.70 mg/kg). 

2 Pink indicates sample above the San Francisco Bay RWQCB environmental screening level for commercial/industrial use (10.00 mg/kg). 

3 Concentrations of mercury are provided in mg/kg; however, mg/kg and ppm are equal and can be used interchangeably 


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Table 13 

Upper Guadalupe River Reach 12 Sediment Sampling and Analysis Results 

Sample 

Sample Type 

Grain Size (%) 

Total Organic 

Total 

Mercury R 2 - 3 

Gravel 

Sand 

Carbon (%) 

Solids (%) 

(mg/kg) 


RWQCB's mercury requirements for reusing excavated sediment for fill material (mg/kg = ppm): 


• 2.3-5.0 ppm (or mg/kg) at a depth equal to or greater than 2 feet below finish grade within 20 feet of the low flow channel, or at any 
depth if more than 20 feet from the low flow channel 

• 5.0-20.0 ppm (or mg/kg) can be used above the 50-year flood elevation and must be covered with erosion control blankets (if it drains to 
into the river) and hydroseeded. 

Source for data: Upper Guadalupe River Reach 12 Sampling and Analysis Report (USACE 2013). 


Upper Guadalupe Flood Control Project, Reach 12 

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UGR-Ri2-2012-2-3 

HQ 4 15 mgAtg 
Depth 6 4411 


1-R12-2012-2-4 

Hg IBSmgAg 
Depth 6 44n 


_12-2012-2-5 

Hg 0 613rogAg 
Oepth 7 7511 



REACH 12 COMPOSITES 

AREA 1 AREA 2 

UGR-R12-2012-1 UGR-R 12-2012-2 

Hg 3 60mgAg Hg 6 59mgAg 

Depth 0-5aon Depth 04 66(1 

UGR-R12-2012-1Z UGR-R12-2012-2Z 

Hg 13.50 mgAtg Hg 4 53 mgAtg 

Depth 1 89-6 3011 Depth 6 794 1511 


UGR-R 12-2012-3 
Hg 3 70mgArg 
Depr 0-101711 

UGR-R12-2012-3Z 
Hg 7 46 mgAtg 
Depr 7 14-106711 


UGR-H12-2012-3-4- 

Hg 17 20rrgAg 
DepPi 66411 


75 0 75 125 


Figure 15. Sediment Mercury Sampling Locations, Depths, and Results * 


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Significance Criteria: The project would have a significant effect on sediment quality if it would 
degrade sediment quality during construction or leave exposed sediment with mercury 
concentrations that could harm organisms or violate water quality standards. 

3.3.1 Potential Impacts and Mitigation Measures 

As part of the project, approximately 10,200 cubic yards of sediment would be excavated to create 
flood benches, maintenance roads, and ramps. The project also requires approximately 12,400 
cubic yards of fill, of which 1,700 cubic yards needs to be clean cover material. The remaining 
10,700 cubic yards would come from excavated sediment. Some of the sediment proposed for 
excavation is shown to contain mercury-laden sediment. Depending on the concentrations of 
mercury, this sediment could be either reused in various areas of the project. The USACE and 
SCVWD worked closely with the San Francisco RWQCB to determine how mercury-laden soils can 
be reused in the project area. Table 14 and Figure 16 and described below. 


Table 14 Requirements for Reusing Soil with Mercury 

Location 

Mercury 

Concentration 

(ppm) 

Reuse Requirements 

Within 20 feet of the low-flow 

channel 

0.0-2.3 

No location restrictions. Soil must be 
hydroseeded and covered with coconut fiber 
erosion control blanket. 

Within 20 feet of the low-flow 

channel 

2.3-5.0 

Soil must be buried under 2 feet of clean 
sediment. Cover soil must be hydroseeded and 
covered with coconut fiber erosion control 

blanket. 

From 20 feet landward of the 
low-flow channel up to the 50- 
year water surface elevation 

0.0-5.0 

Soil must be hydroseeded and covered with 
coconut fiber erosion control blanket. 

Anywhere above the 50-year 
water surface elevation (e.g. 
berms at top of bank] 

5.0-20.0 

Soil must be hydroseeded, and if draining into 
the river covered with coconut fiber erosion 

control blanket. 

Permitted landfill 

over 20.0 or 

excess material 

Soil must be removed from the site and 
disposed of at a properly-permitted landfill. 


Upper Guadalupe Flood Control Project, Reach 12 

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Maintenance 

Road 


Maintenance 

Road 


Soil with 5-20 ppm of mercury may be 
reused on sites above the 50-year flood level. 


Soil with mercury from 2.3 to 5.0 ppm of 
mercury may be reused anywhere. If reused 
within 20 feet of the low-flow channel it must 
be buried under at least two feet of soil with 
under 2.3 ppm of mercury. 


Soils exposed by excavation within the 
channel may have mercury at levels from 
5.0 to 20 ppm. 





Percolation 
Pond 
No. 3 


50 vcar Water Surface tlevanon 


Grade 


Bank Full Water Surface tlevanon 


Elevation 


Grade 
' Elevation 


Gravel Augmentation 
(where proposed) 


100-year Water Surface Elevation 


Percolation 
pond 
\ No. 1 

VOX 


Note: All cut and fill slopes will be hydroseeded, and all that drain directly or indirectly into the river will be covered with erosion control fabric. 


Figure 16. Requirements for Reusing Soil Containing Mercury in the Project Area 


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As shown in Table 15 approximately 18,000 cubic yards of sediment would be excavated to create 
flood benches. In areas within 20 feet of the low flow channel, an additional 1,500 cubic yards 
would be excavated to necessitate the required 2-foot backfill. Approximately 1,500 cubic yards of 
clean backfill material would be imported to the project site to cover mercury-laden soils within 
areas 20 feet from the low flow channel (imported material would require approximately 150 
trucks]. The estimated volume of fill in areas outside of the 20-foot low flow channel area is 
approximately 9,400 cubic yards. The material excavated in the flood bench areas would be used as 
fill material and no additional material would be trucked in (beyond the 1,500 cubic yards of clean 
backfill material]. The remaining 8,600 cubic yards of excavated material would either be directly 
placed into trucks for disposal at an authorized facility or stockpiled into areas for later disposal. 
Stockpile areas would be constructed to isolate stored mercury-laden sediment from the 
environment. The stockpile area would be lined with a chemically resistant geomembrane liner to 
prevent precipitation from entering the stockpile. The liner system would be sloped to allow 
collection any leachate. Additionally, berms at least 12 inches in height would be constructed 
around each stockpile. 


Table 15 Reach 12 Excavation, Fill and Aggregate Requirements 

Construction 

Element 

Proposed 

Excavation 

(cubic yards) 

Proposed Fill 
(cubic yards) 

Aggregate 

Surface 

(cubic yards) 

Required Truck 
Loads 

Flood benches 

7,900 

52 

- 

0 

Backfill 1 

1,500 

1,500 

- 

150 

Maintenance 

Roads 

280 

- 

2,530 

253 

Ramps 

15 

516 

74 

7 

Total 

15,600 

10,073 

591 

209 

1 Backfill areas are within 20 feet of the low flow channel to excavate and cover sediment with mercury 
concentrations of 2.3-5.0 ppm. Soil for backfill material would be imported. 


Excavating sediment containing mercury and using it for fill could expose biological receptors or 
water to elevated concentrations of mercury. Preventing erosion of mercury-laden soils into the 
river would prevent mercury from adversely affecting water quality. In addition, in-situ sediment 
within 20 feet of the low flow with mercury concentrations greater than 2.3 ppm would be 
excavated and backfilled with clean sediment, thereby minimizing the potential for mercury to 
affect water quality following construction. 

As mentioned, soils containing concentrations of mercury between 2.3-20 ppm can be reused for 
fill in certain areas of the project area, depending on the concentration. All soil reuse would comply 


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with the requirements set forth by the San Francisco Bay RWQCB as described in Table 14 and 
Figure 16. Recent sediment testing has shown that the sediment proposed for excavation and fill 
has mercury content of less than 20 ppm. These concentrations of mercury in the sediment are not 
expected to result in adverse effects to biological receptors given the implementation of Avoidance, 
Minimization, and Mitigation Measure SQ-1,2, 3, 4, and 5. 

Impact SQ-1: Degrade sediment quality during construction or after construction. The proposed 
project is designed to avoid degrading sediment quality during construction. The project proposes 
to remove the upper 2 feet of sediment with concentrations of mercury above 2.3 ppm from all 
areas within 20 feet of the low flow channel and back fill these areas with clean sediment (see 
Avoidance and Minimization Measure SQ-1). This would result in a beneficial effect on sediment 
quality in the project area following construction. Sediment reused in areas above the 50-year 
flood level would not have concentrations of mercury higher than 20 ppm. Additionally, Avoidance, 
Minimization, and Mitigation Measure SQ-2, 3, 4, and 5 would also ensure that construction-related 
sediment would not erode into the river. As such, this impact is anticipated to be less than 
significant. 

Impact SQ-2: Expose water or biological receptors to concentrations of mercury that would violate 
standards. The USACE and SCVWD have worked closely with the San Francisco Bay RWQCB to 
ensure that construction of the project would comply with the requirements of the Upper 
Guadalupe River Flood Risk Management Project WDR and NPEDS permit. The following avoidance 
and minimization measures ( Avoidance, Minimization, and Mitigation Measure SQ-1,2, 3, 4, and 5] 
would be employed to ensure that impacts to water quality or biological receptors resulting from 
exposure of mercury-laden sediment are less than significant. 

Avoidance, Minimization, and Mitigation Measures: 

Avoidance and Minimization Measure SQ-1: Comply with the San Francisco Bay RWQCB’s 
requirements for reuse of mercury-laden sediment (see Table 14]. 

Avoidance and Minimization Measure SQ-2: Utilize erosion control measures to ensure that 
mercury-laden sediment does not erode into the adjacent river. 

Avoidance and Minimization Measure SQ-3: Utilize best management practices to ensure that 
mercury-laden sediment does not erode into the adjacent river. 

Avoidance and Minimization Measure SQ-4: All stockpiling of sediment shall be conducted in such 
a manner that prevents sediment from eroding into adjacent areas or streams. 

Avoidance and Minimization Measure SQ-5: Dispose of mercury-laden sediment at approved 
upland facilities. 


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3.4 


Water Quality 


Water quality is regulated by the State Water Resources Control Board and its subsidiary Regional 
Water Quality Control Boards. The Guadalupe River is within the jurisdiction of the San Francisco 
Bay Regional Water Quality Control Board (RWQCB], The RWQCB is responsible for implementing 
state and federal water quality regulations; specifically, they implement the Water Quality Control 
Plan (Basin Plan] for the region. The Basin Plan establishes the beneficial uses of water bodies. The 
Guadalupe River is subject to requirements of the San Francisco Bay Basin Plan. This plan identifies 
the following beneficial uses of Guadalupe River: warm freshwater habitat, wildlife habitat, and 
non-contact water recreation. 

The hydrology of the watershed and whether the season is dry (summer] or wet (winter] affects 
water quality parameters. During the dry season, the water flow is low, water temperatures are 
higher, dissolved oxygen is low, and increased nutrients, bacteria, and algae growths are present. 
During the wet season, increased precipitation and corresponding stormwater runoff result in 
higher stream flows the river can be adversely affected by eroded sediment and other constituents 
of concern. 

The water quality in the Guadalupe River is also influenced by both past and current land use 
activities in the surrounding watershed. The river's water quality is designated as impaired under 
the CWA Section 303(d] by urban pesticides (diazinon], mercury, and trash (USEPA 2010], 

Diazinon impairment is likely a result of urban runoff from the surrounding watershed; illegal 
dumping and other spills have resulted in trash impairment; and mine tailings from the New 
Almaden mines have resulted in mercury impairment (USEPA 2010], A mercury total maximum 
daily load (TMDL] was included in the Basin Plan under Resolution Number R2-2008-0089 in 2008 
and approved by the USEPA in 2010. A TMDL also exist for diazinon. 

Waste Discharge Requirement (Order No. R2-2003-0015): The RWQCB has issued a Waste 
Discharge Requirement for the federal Upper Guadalupe River Flood Control Project (RWQCB, 

2003; Orders No. R2-2003-0115], The water quality characteristics which require monitoring 
include pH, settleable matter, dissolved sulfide, temperature, dissolved oxygen, turbidity, and other 
characteristics determined by visual or olfactory senses (e.g., oil and odor]. Table 16 provides 
details of the limits of each constituent. Order No. R2-2003-0115 is available in Appendix F. 

Guadalupe River Water Quality: Historic water quality data from years 1946 through 1994 are 
summarized in the 1999 EIR/EIS in Section 4.3. These data show that river water and sediment 
contained mercury, lead, copper, zinc, and other trace pollutants (USACE and SCVWD 1999a], 
Although water quality monitoring has not been recently conducted in Reach 12, water quality data 
exists for Reaches 10B and 6. Morning and evening water quality measurements were taken both 
upstream and downstream of water diversions in 2012 (Reach 10B] and 2011 (Reach 6] during the 
in-channel work windows (June 1-October 15]. Water quality monitoring was conducted in these 
reaches during construction to comply with the WDR. Measurements upstream of water diversions 
are considered ambient conditions (i.e., measurements were taken in waters that were not 


Upper Guadalupe Flood Control Project, Reach 12 

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impacted by diversion or other construction-related activities]. Measurements taken downstream 
of diversions indicated the effects of the diversion on water quality (i.e., receiving waters). 


Table 16 WDR Order No. R2-2003-0115 Water Quality Limitation 

Measurements 

Effluent Limitations 

pH 

0.5 pH units above or below ambient levels 

Settleable matter 

1.0 milliliters per liter per hour (ml/l/hr) 

Dissolved sulfide 

0.1 milligrams per liter (mg/1) 

Temperature 

2.8 °C (5 °F) maximum increase above ambient levels 

Receiving Water Limitations 1 

pH 

Variation in ambient pH by more than 0.5 pH units 

Dissolved oxygen 

7.0 mg/1 minimum (when ambient is less, no further reduction) 

Temperature 

2.8 °C (5 °F) maximum increase above ambient levels 

Turbidity 

Background 

Incremental Increase 

<50 units 

5 NTU 

>50 units 

10% of background, maximum 

Visible Observations 

At any place more than 100 feet downstream from the point of 
discharge no: floating, suspended or deposited macroscopic 
particular matter or foam; alteration of apparent natural color; 
visible floating, suspended, or deposited oil; toxic or other 
deleterious substances. 

NOTES: 

1 Per the self-monitoring plan, receiving water is measured 100 feet downstream from the point of discharge. 
Source: WDR R2-2003-0115 (San Francisco Bay RWQCB 2003) (available in Appendix F). 


Reach 6 and 10B water quality parameters measured are summarized below in Table 17 (Reach 
10B) and Table 18 (Reach 6). Detailed water quality monitoring data are provided in Appendix B. 
While these areas are further downstream from Reach 12, they do present some information of the 
quality of water within the entire river. Further, it is anticipated that impacts resulting from 
construction of Reach 12 would be similar to those that occurred during the construction of 
Reaches 10B and 6. 

Reach 10B monitoring occurred both up and downstream of diversions from September 8-21, 2012 
(approximately 1.5 miles downstream of Reach 12). A total of 27 measurements were taken over a 


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period of 14 days. Measurements included low, pH, conductivity, turbidity, dissolved oxygen, 
temperature, salinity, and total dissolved solids. During construction, no objectionable odors or 
visual floating, suspended sediment, foam, alteration of color, oil, or other toxic or deleterious 
substance was observed. Table 17 summarizes the minimum, maximum, and average water quality 
measurements for each parameter. Table 17 is followed by an assessment of any exceedances of 
WDR limitations. 


Table 17 Water Quality Measurements taken during Construction of 

Reach 10B (2012) 

Parameter 

Measured 

Upstream 

(ambient conditions) 

Downstream 

(receiving waters) 

Minimum 

Maximum 

Average 

Minimum 

Maximum 

Average 

Temperature 

TO 

17.54 

24.33 

20.75 

16.69 

23.70 

20.66 

Turbidity 

(NTU)t 

2.90 

19.40 c 

(10.70) 

8.97 

1.10 

24.20 c 

(11.10) 

6.04 

Dissolved Oxygen 
(mg/L) d 

6.92 

10.83 

8.84 

5.74 

10.30 

8.15 

TDS 

0.28 

0.39 

0.29 

0.26 

0.31 

0.29 

pH 

6.77 

8.53 

7.95 

7.18 

8.43 

8.09 

Salinity 

0.20 

0.20 

0.20 

0.20 

0.20 

0.20 

Conductivity 

0.43 

0.46 

0.45 

0.42 

0.48 

0.45 

NOTES: 

b Turbidity requirements: 

Upstream turbidity is between 0 and 50 NTUs, downstream turbidity cannot have an increase of more than 5 NTUs. 
Upstream turbidity is greater than 50 NTUs, downstream turbidity cannot have an increase of more than 10 
percent. 

c The highest measured turbidity occurred the day the channel was re-watered (September 19). The measurement 
was higher compared to all other measurements. The highest measurement was 10.70 NTU (upstream) and 11.10 

NTU (downstream). Both measurements are provided in the table. 
d DO requirements: minimum of 7.0 mg/L. 

Source: USACE2012. Reach 10B construction water quality monitoring. 


Reach 10B (2012) 

• Temperature: Temperature upstream of the diversion ranged from 17.45-24.33 degrees 
Celsius (°C), while downstream temperatures ranged from 16.69-23.70 °C. Data show that 
the change in water temperature between up- and downstream measurements were not 
consistently higher or lower. Eight (8] receiving water measurements showed a slight 
increase in temperature from upstream to downstream and 19 measurements showed a 


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slight decrease (Appendix B], The largest change was an increase of 2 °C; the largest 
temperature decrease was 1.58 °C. These measurements indicate that the temperature 
changes did not exceed the WDR limitation of a rise of 2.8 °C above ambient conditions. 

• Turbidity: Turbidity ranged from 2.9 to 10.7 Nephelometric Turbidity Units (NTU) 
upstream of the diversion, and rose as high as 19.4 NTU during re-watering of the channel. 
Turbidity ranged from 1.10 to 11.1 NTU downstream of the diversion, and rose to 24.2 NTU 
during re-watering of the channel. Seven [7] of the receiving water measurements showed 
a downstream increase in turbidity and 20 showed a decrease (Appendix B], According to 
the WDR, if background turbidity is less than 50 NTU, the incremental increase cannot be 
more than 5 NTU. Six (6] of the 27 monitoring results showed that an increase of 5 NTU; 
these measurements were taken on September 12,14,15,17, and 19. During re-watering of 
the channel, downstream turbidity measurements showed an increase in turbidity of 5.8 
and 4.8 NTU (upstream and downstream, respectively], compared to upstream turbidity. 

• Dissolved Oxygen: Dissolved oxygen ranged from 6.92 to 10.83 mg/L upstream and 5.74 to 
10.30 mg/L downstream. Eight (8] measurements showed an increase in receiving water 
dissolved oxygen concentrations and 19 showed a decrease (Appendix B], The WDR 
limitations require that dissolved oxygen levels do not drop below 7.0 mg/L. If ambient 
conditions are already below 7.0 mg/L, no further reduction is allowed. Only one 
measurement showed a drop below 7.0 mg/L (September 17], The ambient condition 
(upstream] was 6.92 mg/L; the downstream concentration was 5.74 mg/L—a decrease of 
1.8 mg/L. 

• pH: Upstream pH ranged from 6.77 to 8.53 and downstream pH ranged from 7.18 to 8.43. 
Nine (9] receiving water measurements showed an increase in pH and 18 showed a 
decrease (Appendix B], The WDR allows for only a 0.5 pH unit change in receiving waters. 
Only one measurement exceeded this limitation—on September 9, downstream pH 
increased by 1 unit. 

Reach 6 monitoring up and downstream of construction in 2011 (approximately 4 miles 
downstream]. Monitoring includes visual observations (particulate matter, foam, color, oil or 
petroleum, and other toxics], temperature, turbidity, pH, and dissolved oxygen (Table 18], Sixty- 
two (62] measurements were taken over a period of 31 days (June 22 through July 23Following], 
Results of all measurements are provided in Appendix B. Table 18 is followed by an assessment of 
exceedances of the WDR limitations. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 7 6 




Table 18 Water Quality Measurements taken during Construction of 

Reach 6 

Parameter 

Measured 

Upstream 

Downstream 

Minimum 

Maximum 

Average 

Minimum 

Maximum 

Average 

Virginia Avenue Diversion 

Temperature 

TO 

20.20 

26.60 

22.77 

19.70 

26.10 

22.69 

Turbidity 

(NTU)t 

24.80 

94.20 

37.32 

26.50 

104.00 

39.13 

Dissolved Oxygen 
(mg/L) c 

5.15 

10.70 

7.84 

5.81 

10.60 

7.88 

PH 

7.30 

8.82 

8.30 

7.32 

8.75 

8.32 

North End Diversion 

Temperature 

TO 

19.60 

26.10 

22.60 

19.80 

26.40 

22.61 

Turbidity 

(NTU)b 

28.40 

62.60 

43.13 

31.70 

61.60 

43.03 

Dissolved Oxygen 
(mg/L) c 

5.73 

9.54 

7.84 

5.57 

9.99 

8.09 

pH 

8.12 

9.47 

8.82 

8.02 

9.45 

8.83 

NOTES: 

h Turbidity requirements: 

Upstream turbidity is between 0 and 50 NTUs, downstream turbidity cannot have an increase of more than 5 NTUs. 

Upstream turbidity is greater than 50 NTUs, downstream turbidity cannot have an increase of more than f 0 percent. 

C D0 requirements: minimum of 7.0 mg/L. 

Source: SCVWD 201T. Reach 6 water quality monitoring. 


Reach 6—Virginia Avenue (2011) 

• Temperature: Temperature upstream of the diversion ranged from 19.70 to 26.10 °C, 
while downstream temperatures ranged from 20.20 to 26.60 °C. Data show that the change 
in water temperature between up- and downstream measurements were not consistently 
higher or lower. Thirty-one (31] of the receiving water measurements showed a slight 
increase in temperature from upstream to downstream, 20 showed a slight decrease, and 
11 showed no change (Appendix B], The largest change was a drop of 2.6 °C (July 6]; the 
largest temperature increase was a rise of 0.08 °C (July 21], These measurements indicate 
that the temperature changes did not exceed the WDR limitation of a rise of 2.8 °C above 
ambient conditions. 


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• Turbidity: Turbidity ranged from 24.8 to 94.2 NTU upstream of the diversion and 26.5 to 
104.0 NTU downstream of the diversion. The maximum measured turbidity occurred on 
June 29; this is due to a rain event that occurred. Thirty (30] measurements showed a 
decrease in measured turbidity downstream of the diversion, 26 showed an increase, and 6 
showed no change (Appendix B], 

According to the WDR, if background turbidity is than 50 NTU, the incremental increase 
cannot be more than 5 NTU and if turbidity is greater than 50 NTU, the change cannot be 
greater than 10 percent of ambient conditions. Three (3] of the ambient turbidity 
measurements were greater than 50 NTU (two measurements on June 29 and one on June 
30]. One of these measurements exceeded the WDR limitation of 10 percent. The 
measurement taken on the morning of June 29 showed that downstream turbidity 
increased by 10.4 percent—from 94.2 to 104.0 NTU. Another exceedance occurred on July 
26 when the downstream measurement showed an increase of 6.5 NTU—from 41.6 to 35.1 
NTU. All other turbidity measurements were below the WDR limitations (Appendix B], 

• Dissolved Oxygen: Dissolved oxygen ranged from 5.15 to 10.70 mg/L upstream and 5.81 to 
10.60 mg/L downstream. Twenty-eight (28] measurements showed an increase in 
receiving water dissolved oxygen concentrations, 32 showed a decrease, and 2 showed no 
change (Appendix B], The WDR limitations require that dissolved oxygen levels do not drop 
below 7.0 mg/L and if ambient conditions are already below 7.0 mg/L, no further reduction 
is allowed. Six (6] receiving waters showed that dissolved oxygen concentrations dropped 
below 7.0 mg/L (June 22 and 24 and July 5, 7, 9,12,13 and 21]; these were the only 
measurements that exceeded the WDR limitations. Seven (7] measurements showed 
increases in dissolved oxygen concentrations from upstream values of below 7.0 mg/L. The 
largest receiving water increase in dissolved oxygen concentrations was a rise of 4.42 mg/L; 
the largest decrease was 3.02 mg/L. 

• pH: Upstream pH ranged from 7.30 to 8.30 and downstream pH ranged from 7.32 to 8.75. 
Thirty (30] of the receiving water measurements showed a increase in pH from upstream to 
downstream, 31 showed a decrease, and 2 did not change (Appendix B], None of the 
receiving water measurements showed a change in pH 0.5 units above or below ambient 
conditions. The WDR allows for only a 0.5 pH unit change in receiving waters. 

Reach 6—North End (2011) 

• Temperature: Temperature upstream of the diversion ranged from degrees °C, while 
downstream temperatures ranged from 19.60 to 22.60 °C. Data show that the change in 
water temperature between up- and downstream measurements were not consistently 
higher or lower. Fifty (50] of the receiving water measurements showed a slight increase in 
temperature from upstream to downstream, 37 showed a slight decrease, and 8 showed no 
change (Appendix B], The largest change was a drop of 3.5 °C (August 19]; the largest 


Upper Guadalupe Flood Control Project, Reach 12 

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temperature increase was a rise of 1.4 °C (September 10). These measurements indicate 
that the temperature changes did not exceed the WDR limitation of a rise of 2.8 °C above 
ambient conditions. 

• Turbidity: Turbidity ranged from 28.4 to 62.6 NTU upstream of the diversion and 31.7 to 
61.6 NTU downstream of the diversion. Thirty-eight (38) measurements showed a decrease 
in measured turbidity downstream of the diversion, 54 showed an increase, and 3 showed 
no change (Appendix B). 

According to the WDR, if background turbidity is than 50 NTU, the incremental increase 
cannot be more than 5 NTU and if turbidity is greater than 50 NTU, the change cannot be 
greater than 10 percent of ambient conditions. The maximum increase in turbidity was 5.0 
NTU (47.4 NTU upstream and 52.4 NTU downstream), measured on August 22. All turbidity 
measurements were within the WDR limitations (Appendix B). 

• Dissolved Oxygen: Dissolved oxygen ranged from 5.73 to 9.54 mg/L upstream and 5.57 to 
9.99 mg/L downstream. Fifty-four (54) measurements showed an increase in receiving 
water dissolved oxygen concentrations, 40 showed a decrease, and 1 showed no change 
(Appendix B). The WDR limitations require that dissolved oxygen levels do not drop below 
7.0 mg/L and if ambient conditions are already below 7.0 mg/L, no further reduction is 
allowed. Ambient conditions (upstream measurements) showed that dissolved oxygen 
concentrations were consistently above 7.0 mg/L. Receiving water (downstream) 
measurements indicated that dissolved oxygen concentrations fell below 7.0 mg/L seven 
(7) times (July 7, 8, 20, 21, 25, and 26); these were the only measurements that exceeded 
the WDR limitation. 

• pH: Upstream pH ranged from 8.12 to 9.47 and downstream pH ranged from 8.02 to 9.45. 
Fifty-four (54) measurements showed an increase in measured turbidity downstream of the 
diversion, 38 showed a decrease, and 3 showed no change (Appendix B). The maximum 
change was a 0.48 increase in pH on September 20. None of the receiving water 
measurements showed a change in pH 0.5 units above or below ambient conditions. The 
WDR allows for only a 0.5 pH unit change in receiving waters. 

In addition to water quality being measured during construction, continuous temperature 
monitoring of the Guadalupe River is required by both the WDR and Biological Opinion for the 
federal Upper Guadalupe River Flood Risk Management Project. Continuous temperature 
monitoring data represent ambient conditions in the river. This EA includes 2011, 2012, and 2013 
data from temperature monitors located in immediately upstream of Reach 12 and in Reach 10B 
(1.5 miles downstream). As shown, temperatures generally are lower in the winter months 
(December through February), increase throughout March through August, and minimally decrease 
in September and October. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 79 




Comparing September 2012 continuous temperature taken in Reach 10B with temperature 
measurements taken up- and downstream of dewatering during September 2012 (Table 17] 
indicates: 

• Minimum continuous temperature (ambient] was higher than both the minimum measured 
temperatures of the upstream water (ambient] and downstream water (receiving water]— 
1.16 °C and 2.01 °C, respectively. 

• Maximum continuous temperature (ambient] was lower than the maximum measured 
temperatures of the upstream water (ambient] and downstream water (receiving water]— 
1.10 °C and 1.90 °C, respectively. 

• Average continuous temperature (ambient] was lower than the average measured 
temperatures of the upstream water (ambient] and downstream water (receiving water]— 
0.31 °C and 0.26 °C, respectively. 

These data indicate that the receiving water was within 2.8 °C of the continuous monitoring 
ambient conditions. Reach 10B was reconstructed in 2012; as such, the area had limited riparian 
forest and shaded riverine aquatic cover which helps to reduce water temperatures. However, 
comparing the Reach 10B and upstream Reach 13 (which has riparian forest and shaded riverine 
aquatic cover] show that the temperatures between the two reaches are similar throughout the 
year. 

Significance Criteria: The project would have a significant impact on water quality if it would: 

• Violate any water quality standard or waste discharge standard set by the RWQCB or 
substantially degrade water quality. 

• Substantially contribute to runoff water which would exceed the capacity of existing or 
planned stormwater drainage systems. 

3.4.1 Potential Impacts and Mitigation Measures 

The redesign of Reach 12 is intended to excavate steep benches adjacent to the river channel 
thereby creating flood benches which would receive overflow more often. This would tend to 
reduce water velocities during high-flow events and may reduce erosion and sediment mobilization 
into the stream bed. Other construction activities, such as installing instream structures and gravel 
augmentation have the potential to adversely affect Guadalupe River water quality by increasing 
erosion and sediment mobilization into the river. Dewatering the channel also has the potential to 
adversely affect water quality should groundwater seep from the percolation ponds (located at a 
higher elevation than the river] leak into the dewatered channel. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


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Table 19 


Continuous Temperature Monitoring 




Measure 

Jan 

Feb 

Mar 

Apr 

May 

Jun 

Jul 

Aug 

Sep 

Oct 

Nov 

Dec 

Immediately Upstream 

2013 

Min 

7.3 

8.8 

11.8 

14.2 

17.1 

19.3 

21.7 

21.4 

18.9 

17.4 

- 

- 

Max 

13.5 

15.8 

16.5 

24.1 

21.7 

25.4 

26.1 

25.0 

24.6 

20.9 

- 

- 

Ave 

9.9 

11.5 

14.1 

18.9 

19.2 

21.6 

23.2 

23.1 

21.9 

18.9 

- 

- 

2012 

Min 

- 

- 

- 

16.2 

16.8 

18.0 

21.3 

21.2 

19.8 

17.5 

13.2 

9.2 

Max 

- 

- 

- 

23.5 

22.9 

24.2 

25.1 

25.2 

23.2 

22.3 

18.0 

15.2 

Ave 

- 

- 

- 

19.1 

19.3 

21.0 

22.8 

22.9 

21.3 

19.6 

15.3 

15.4 

2011 

Min 

- 

- 

- 

15.3 

15.1 

16.1 

19.9 

21.3 

20.0 

20.3 

- 

- 

Max 

- 

- 

- 

17.1 

19.7 

22.9 

25.5 

24.0 

23.1 

21.7 

- 

- 

Ave 

- 

- 

- 

16.1 

17.2 

19.6 

22.1 

22.5 

21.7 

21.0 

- 

- 






Downstream 











(Reach 10B) 






2013 

Min 

- 

- 

- 

14.8 

17.1 

18.9 

21.0 

20.4 

17.0 

14.2 

- 

- 

Max 

- 

- 

- 

21.2 

21.4 

25.4 

25.9 

24.1. 

23.2 

19.7 

- 

- 

Ave 

- 

- 

- 

18.3 

19.2 

21.3 

22.7 

22.1 

20.6 

16.4 

- 

- 

2012 

Min 

- 

- 

- 

16.6 

16.8 

18.1 

20.8 

20.2 

18.7 

16.4 

- 

- 

Max 

- 

- 

- 

20.8 

20.8 

23.6 

24.4 

24.3 

21.8 

31.2 

- 

- 

Ave 

- 

- 

- 

18.6 

19.1 

20.8 

22.2 

22.1 

20.2 

18.9 

- 

- 

2011 

Min 

- 

- 

- 

15.8 

14.4 

15.6 

19.9 

20.8 

19.7 

20.1 

- 

- 

Max 

- 

- 

- 

17.1 

20.4 

23.6 

24.4 

23.3 

22.8 

21.0 

- 

- 

Ave 

- 

- 

- 

16.4 

17.3 

19.9 

22.3 

22.2 

21.4 

20.5 

- 

- 

Source: SCVWD continuous temperature monitoring (2011-2013). 


Impact WQ-1: Violate any water quality standard or waste discharge standard set by the RWQCB or 
substantially degrade water quality. Dewatering the channel could adversely affect receiving water. 
As discussed above, monitoring up- and downstream of dewatering activities in Reaches 6 and 10B 
did not show that the receiving water was adversely affected. At times individual measurements 
exceeded the WDR limitations for the project (see Table 16 for WDR limitations]; however, overall 
the data show variability above and below ambient conditions for each parameter measured. 


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Therefore, changes to receiving water may be a result of various factors, some of which may not be 
related to construction activities. 

Prior to in-channel work being conducted, the reach or portions of the reach would be dewatered, 
thereby routing the flow of the river around construction activities. The river would be also 
protected by erosion control best management practices during construction in upland areas (areas 
above low-flow], thereby protecting water quality. Specific erosion control measures are discussed 
in the Avoidance, Minimization, and Mitigation Measures below. Implementation of Avoidance and 
Minimization Measure WQ-1, W2-2, and WQ-3 would ensure that impacts to water quality are 
anticipated to be less than significant. 

Impact WQ-2: Increase the concentration of any CWA 303(d) substance identified for Guadalupe 
River (mercury, diazinon, or trash) or violate the river’s TMDLs (mercury and diazinon). The 
proposed project would excavate and reuse sediment known to contain mercury. During planning, 
sediment mercury content was analyzed to determine the concentrations of mercury in sediment 
proposed for excavation. Additionally, the USACE worked with the RWQCB to determine acceptable 
criteria for reuse of mercury-laden sediment. Sediment proposed for reuse in the project area 
would follow the requirements provided by the RWQCB. 

Trash is common along the Guadalupe River and is likely a result of transient use, illegal dumping, 
and urban runoff. During construction, trash would be removed from the project site—including 
the channel once it is dewatered—thereby reducing the volume of trash in the reach. During the 4- 
year maintenance period, trash would be removed from the reach in areas outside of the channel. 
This would reduce the trash volume in the reach in during the years when construction and 
maintenance occurs. 

Diazinon is transported to the Guadalupe River from runoff. The project would not result in 
additional diazinon entering the river. 

By implementing complying with the sediment-mercury reuse criteria and removing trash from the 
site [see Avoidance and Minimization Measure WQ-3), the project would locally reduce mercury and 
trash input into the river. As mentioned, the project would have no effect on diazinon. As such, this 
impact is expected to be beneficial. 

Impact WQ-3: Substantially contribute to runoff water which would exceed the capacity of existing 
or planned stormwater drainage systems. The project is not anticipated to create runoff water that 
would exceed the capacity of existing or planned stormwater drainage systems. The project would 
use water trucks to help reduce fugitive dust; however, the trucks would be used in a manner that 
does not create runoff. Should any runoff be generated during construction, compliance with 
Avoidance and Minimization Measure WQ-1 would ensure that impacts are less than significant. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 82 




Avoidance, Minimization, and Mitigation Measures 

Avoidance, minimization, and mitigation measures were identified to ensure that potential impacts 
to water quality would be less than significant during construction of the reach. Erosion control 
measures are identified in the WDR and National Discharge Pollution Prevention Plan (NDPPP); 
compliance with these measures would ensure that erosion or sedimentation would not affect the 
river bed. Compliance with the erosion control requirements of the WDR and NDPPP permits 
would ensure that any impacts to groundwater from construction-related erosion and 
sedimentation would be less than significant. Avoidance and minimization measures are identified 
below. 

Avoidance and Minimization Measure WQ-1: Comply with erosion control measures identified in 
the Construction General National Pollution Discharge Elimination System (NPDES) permit. 

• Erection of barrier fencing and sediment and erosion control systems in the project site— 
barrier fence and sediment and erosion control systems within and/or around the portion 
of the site that would be graded. Erosion control systems may include fiber rolls, straw 
bales, silt fences, and other acceptable measures. 

• Establish and fence the equipment servicing and staging area. 

• Isolate and manage stormwater runoff and potential fuel or fluid spills from the equipment 
service area. As necessary and required for isolation and control of stormwater or other 
vehicle fluid discharges to adjacent waters/wetlands. 

• Designate a supervisor for the equipment service and staging area. This person will be 
responsible for daily clean-up and maintenance of the service and staging area, for 
coordination of spill response, and for all communication pertinent to the area and its 
operation and maintenance. 

Avoidance and Minimization Measure WQ-2: Comply with the water quality limitations provided 
in the WDR (Order No. R2-2-2003-0115) for the Upper Guadalupe Flood Control Project. 

• Monitor dewatering activities to ensure that water quality objectives are met prior to 
returning water to the river (water quality objectives are identified in Table 16). 

• Provide annual reporting to the San Francisco Bay RWQCB on the results of all monitoring. 

• Implement best management practices to prevent erosion and siltation into the river. 

Avoidance and Minimization Measure WQ-3: Comply with the mercury and diazinon TMDLsfor 
Guadalupe River and ensure that concentrations ofCWA 303(d) constituents listed for Guadalupe 
River (mercury, diazinon, and trash) are not increased. 

• Comply with the RWQCB's sediment reuse criteria for mercury laden sediment for the 
proposed project (see Table 14). 

• Remove trash from the project site during construction. 


Upper Guadalupe Flood Control Project, Reach 12 

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United States Army Corps of Engineers 


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• Remove trash from the channel when following dewatering. 

• Remove trash from the reach each year during vegetation maintenance. 

3.5 Biological Environment 

As previously mentioned, the primary purpose of constructing Reach 12 is to mitigate the habitat 
impacts of constructing the entire federal Upper Guadalupe River Flood Risk Management Project. 
This was also the intent of the design for this reach in the 1999 EIS/EIR and Mitigation Monitoring 
Plan (SCVWD and USACE 1999b], The 1999 mitigation design concept developed for Reach 12 
included the restoration of approximately 6.45 acres of riparian forest and 975 linear feet of SRA 
cover (SCVWD and USACE 1999b], primarily off-stream. 

The original concept was to provide a general plant palette to guide future plant selection at 
different stream bank locations. The plant palettes would then be further developed and refined 
during the detailed design phase for Reach 12. The re-vegetation design concept is to attain 
multiple beneficial environmental objectives while meeting the basic purpose of flood risk 
management. The 1999 Mitigation Monitoring Plan is incorporated by reference in this document. 

At the time the 1999 design was developed, Reach 12 was sparsely vegetated by woody plants. 

Most woody plants at that time were on sections of the upper channel bank or on the high terrace. 
Areas of open water and emergent marsh vegetation were also present. However, in the 14 years 
following development of this initial concept, large parts of Reach 12 have been colonized by native 
riparian tree species. This growth has reduced the amount of available planting area, and most 
remaining space that lacks trees has limited water availability. As a result, fewer acres are available 
for riparian forest planting. 

The 1999 design was based on the assumption that permits for seasonal instream spreader dams 
and associated instream percolation ponds would be restored, and that the bulk of the river 
channel would be unavailable for habitat restoration. Wetland and riparian forest restoration 
would be largely placed on the margins of off-stream percolation ponds with stable water levels. 

Since then, this plan has become infeasible. The California Department of Fish and Wildlife [CDFW] 
did not renew permits for instream spreader dams at this location, and the parcel intended for off- 
stream percolation and mitigation could not be acquired. Meanwhile, most locations in the channel 
which are suitable for riparian vegetation became naturally revegetated, albeit in some cases with 
non-native trees and shrubs. Therefore, the new plan seeks to maximize habitat quality within the 
river channel with mitigation plantings and habitat structures placed in available locations, subject 
to hydraulic and biological constraints. 

The goals of the current plan for which this supplemental EA was prepared have not changed much 
since the 1999 EIR/EIS was prepared; however the project proposed to attain those goals has 
changed. To achieve the habitat improvement goals, the proposed project includes laying back 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 84 




steep banks to create flood benches; improving river morphology by creating flood benches, 
installing instream structures; augmenting gravel; and planting native riparian vegetation. 

However, as a result of colonization of riparian vegetation in the reach, the acreage of riparian 
planting areas under the current design is limited. Hydraulic modeling conducted for the proposed 
project has verified this and shown that additional planting zones in the channel would have a 
negative impact on channel capacity by increasing channel roughness. Therefore, the current 
design limits instream planting zones to planting vegetation on proposed instream structures (e.g., 
rootwads and log jams], benches, and limited locations elsewhere. 

3.5.1 Existing Habitat 

The Guadalupe River is located in urban San Jose, California. The natural corridor of the river is 
rather narrow and adjacent to the river's corridor are groundwater recharge ponds, groundwater 
wells, residential, commercial, and other urban development. However, the corridor does provide 
riparian and upland habitat for several species of wildlife. Surveys of the site show the following 
habitat types are present: herbaceous ruderal, oak/sycamore woodland, willow/cottonwood/alder 
riparian forest, emergent aquatic wetland, and riparian scrub. Exotic trees, pavement, and open 
areas were also identified. Very small areas of non-native blackberry were present. Table 19 and 
Figure 17 and Figure 18 provide details of the land cover and habitat types surveyed in Reach 12. 

As shown, the project area has 10.09 acres of riparian forest. Additionally, SRA cover is present 
along most of the channel. SRA cover is defined as riparian forest within 15 feet of the low flow 
channel, wood debris that provides aquatic cover, or undercut banks. 

3.5.2 Existing Fish and Wildlife 

Species that utilize Reach 12 include egrets, mallard, Canadian goose, white and golden-crowned 
sparrows, western scrub jays, amer robins, Brewer's blackbirds, starlings, American Kestral, Black 
Phoebe, Yellow-rumped warblers, ruby-crowned kinglets, house finch, lesser goldfinch, Anna's 
humming bird, red-winged blackbird, and song sparrow. At times, hawks can be seen using areas of 
the river, or flying over the river (Guadalupe River Park Conservancy 2012], These hawks and 
other migratory birds in the project area are protected under the Migratory Bird Treaty Act 
(MBTA], Mammals such as skunks, jackrabbits, and squirrels utilize the river and upland habitats. 
Western fence lizard and bullfrog are also a common species in the project area. Many of these 
species were observed using Reach 10B during 2013 wildlife monitoring following construction. 

Fish species known to inhabit Guadalupe River include native Sacramento sucker, prickly sculpin, 
and California roach, and non native common carp, largemouth bass, bluegill, green sunfish, and 
steelhead. During dewatering of Reach 10B (downstream of Reach 12], a fish biologist was present 
to relocate fish from upstream of the diversion to downstream in the free-flowing river. The 
objective of the fish relocation efforts were to 1] transfer any captured juvenile steelhead to the 
main channel downstream of the construction area with no loss of life; 2] transfer all other 
captured native fishes to the main channel below the construction reach with minimal loss of life; 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 85 




and 3] remove and kill all nonnative fish from the channel and properly dispose of them. A total of 
185 fish removed from this relocation effort, including 107 native fish that were relocated 
downstream of the construction site and 78 nonnative fish that were killed and disposed of. One 
juvenile steelhead was caught and released downstream unharmed. Table 20 shows the fish that 
were caught and relocated. 


Table 19 Existing Land Cover Habitat Types 

Land Cover Class 

(Habitat) 

Total Existing Area 1 
(acres) 

Herbaceous Ruderal 

8.80* 

Oak / Sycamore Woodland 

1.63 

Willow / Cottonwood / Alder Riparian 
Forest 

7.83 

Emergent Aquatic 

0.415* 

Exotic Trees 

0.95* 

Open 

8.44* 

Other Exotic 

0.80* 

Pavement 

0.88* 

Riparian Scrub 

0.63 

Water 

1.74* 

Total Riparian Forest and Scrub 

10.09 

Total Area Mapped 

32.12 

NOTES: 

1 Total habitat mapped includes all habitat types within the project area (including shaded 
riverine aquatic (SRA) cover.] 

* Cover/habitat types are not considered riparian forest or SRA cover and are excluded from 
the total count. 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 86 




















Match Line 



Legend 


Low Flow Water Elevation Surface Level 


15-foot Buffer around Low F ow Water Leve 


Land Cover Classes 

Herbaceous ruderal 

Oak/Sycamore Woodland 

Willow/Cottonwood/Alder Riparian Forest 

emergent aquatic 

exotic trees 

open 

other exotic 
pavement 
riparian scrub 
water 


k ‘ 


Kit 










0.1 Miles 

J i I 


0.025 

J I L 


0.05 


Figure 17. Existing Land Cover (Habitat) in Reach 12 (upstream portion of the reach) 


Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


Page 87 






















Upper Guadalupe Flood Control Project, Reach 12 

Environmental Assessment 

United States Army Corps of Engineers 


This page is intentionally left blank. 


Page 88 





Legend 


Low Flow Water Elevation Surface Level 


4 -Sjjr■ T4 XL 

— i A' 

r; ( L -#8k > 

* . ; § > .* 

^ *V 

iVfe>*v- J J Vi 


15-foot Buffer around Low Flow Water Level 


Land Cover Classes 

Herbaceous ruderal 

Oak/Sycamore Woodland 

Willow/Cottonwood/Alder Riparian Forest 

emergent aquatic 

exotic trees 

open 

other exotic 
pavement 
riparian scrub 
water 


«VIK 

I 




v-« 








Match Line 


0 0.025 0.05 


0.1 Miles 


N 


Figure 18. Existing Land Cover (Habitat) in Reach 12 (downstream portion of the reach) 


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3.5.2.1 Special Status Species 

The project area is within the United States Geological Survey (USGS] San Jose West, San Jose East, 
Los Gatos, and Santa Teresa Hills 7.5 minute quadrangle maps. The USFWS' species generator 
identifies several species and designated critical habitat protected under the Federal Endangered 
Species Act (ESA] or the California Endangered Species Act [CESA] that could be present within the 
area identified in the maps. Table 21 provides a list of all ESA-protected species and critical habitat 
that have the potential to be present in the above-listed 7.5-minute quadrangle map areas, as well 
as a few other species of special concern. It also identifies whether the proposed project has the 
potential to affect each species or their critical habitat. Only species that have the potential to be 
affected by the proposed action are discussed further. 

If individuals of special-status species not protected under the ESA are unexpectedly discovered 
during project construction, the USFWS and/or CDFW will be contacted and appropriate action 
taken in consultation with the agency(s] to avoid or minimize harm to these individuals. 

The overall Upper Guadalupe River Flood Risk Management Project currently has a Biological 
Opinion (NMFS 2005] under the ESA. The proposed Reach 12 project complies with the 2005 BO as 
determined by a letter from the National Marine Fisheries Service dated July 17, 2014. The 2005 
BO is summarized in Section 5.0, Environmental Compliance, and provided in Appendix E. 

California Coastal Steelhead: Steelhead were historically found throughout the Guadalupe River 
system (Skinner 1962, as cited in the Leidy, Becker, and Harvey 2005], After completion of the 
Almaden and Guadalupe Reservoirs in the mid-1930s and Lexington Reservoir in 1952, steelhead 
migration was restricted to tributaries downstream of the dams. By 1962, the steelhead runs had 
declined significantly in the Guadalupe River (Leidy, Becker, and Harvey, 2005], Before fall of 1999, 
steelhead entering the Guadalupe River system were prevented from migrating to upstream 
spawning and rearing areas on the tributary streams by the Alamitos drop structure, located just 
upstream of Reach 12. In 1999, a fish ladder was constructed adjacent to the drop structure. Prior 
to installation of the fish ladder, any steelhead entering the Guadalupe River system were forced to 
spawn in the Guadalupe River and in Los Gatos and Ross Creek. Results of surveys to determine the 
presence of rainbow trout in the mainstream Guadalupe River suggest that rainbow trout are much 
less abundant and less evenly distributed in the river than in the tributary streams; however, it is 
not known whether or not rainbow trout remain in the Guadalupe River during the summer. 

During 2012 dewatering of Reach 10B (approximately 1.5 miles downstream of Reach 12], 
monitoring and fish relocation, one juvenile steelhead was caught and released unharmed. 


Upper Guadalupe Flood Control Project, Reach 12 

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Table 20 Reach 10B Fish Removal and Relocation 

Native Species 

Nonnative Species 

Native Species 
Captured 

Number 

Captured 

Percent of 

Total Fish 
Captured 

Nonnative 

Species 

Captured 

Number 

Captured 

Percent of 

Total Fish 
Captured 

June 2-3,2012 

Lamprey 

(larva) 

1 

<1 

Carp 

3 

2 

Steelhead 

(Juvenile 95mm) 

1 

<1 

Goldfish 

2 

1 

Sacramento 

Sucker 

73 

40 

Yellow 

Bullhead 

1 

<1 

Prickly Sculpin 

16 

9 

Mosquitofish 

12 

6 

California 

Roach 

16 

9 

Largemouth 

Bass 

26 

14 

Total Native 

107 

58 

Bluegill 

14 

8 

Green Sunfish 

20 

11 

Total 

Nonnative 

78 

42 

June 7-8, 2012 

Lamprey 

(larvae) 

2 

4 

Carp 

6 

13 

Sacramento 

Sucker 

13 

28 

Yellow 

Bullhead 

2 

4 

Prickly Sculpin 

5 

6 

Largemouth 

Bass 

10 

21 

California 

Roach 

5 

11 

Green Sunfish 

4 

8 

Total Native 

25 

53 

Total 

Nonnative 

22 

47 


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Table 21 Special Status Species with the Potential to be Present in the Vicinity of the Action Area 1 

Species 

Status 

Critical 

Habitat 

Present in 

the Action 

Area 

Distribution and Habitat Preference 

Potential to 

be Present 

in the 

Project Area 

Potential Impacts 

California tiger 
salamander - Sonoma 
County Population 
(Ambystoma 
californiense) 

FE, ST, CH 

No 2 

California tiger salamander are divided into 
three distinct population segments (DPS)— 
Sonoma County, Central California, and Santa 
Barbara County. Only the Sonoma County 

DPS is known to inhabit Santa Clara County. 
California tiger salamanders are restricted to 
vernal pools and seasonal ponds, including 
many constructed stock ponds, in grassland 
and oak savannah plant communities, 
predominantly from sea level to 2,000 feet, in 
central California. The Sonoma population 
appears to be geographically separated from 
the other California tiger salamander 
populations (USFWS 2009a). 

California tiger salamanders are large 
salamanders that inhabit aquatic habitat free 
of fish and adjacent wetland and uplands 
(USFWS 2009a). The project area does not 
have suitable habitat for California tiger 
salamander. 

No 

None 

California red-legged 
frog 

(Rana draytonii ) 

FT, CH 

No 2 

California red-legged frog occurs from sea 
level to elevations of approximately 5,200 
feet. It is primarily found in coastal drainages 
in the Central California region, including 

No 

None 


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Table 21 Special Status Species with the Potential to be Present in the Vicinity of the Action Area 1 

Species 

Status 

Critical 

Habitat 

Present in 

the Action 

Area 

Distribution and Habitat Preference 

Potential to 

be Present 

in the 

Project Area 

Potential Impacts 




Santa Clara County (USFWS 2002). 

California red-legged frog uses a variety of 
habitats, including aquatic breeding areas 
with a matrix of riparian and upland dispersal 
habitats. Breeding sites include pools and 
backwaters of streams, creeks, ponds, 
marshes, springs, and other aquatic sites 
(USFWS 2002). 

This species has not been found in the 
Guadalupe River or within several miles of it 
for several decades. H.T. Flarvey and 
Associates (1997) concluded that: "The 
species has essentially disappeared from the 
urbanized lowland areas of the county..." The 
combination of non-native bullfrogs and 
predatory fish, together with degraded 
habitat conditions found in heavily urbanized 
areas, is particularly unfavorable to this 
species. 

While the project area could provide suitable 
habitat for California red-legged frog, in the 
sense of aquatic habitat with riparian forest, 
it is extremely unlikely that they would be 
present in the Reach 12 area. 




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Table 21 Special Status Species with the Potential to be Present in the Vicinity of the Action Area 1 

Species 

Status 

Critical 

Habitat 

Present in 

the Action 

Area 

Distribution and Habitat Preference 

Potential to 

be Present 

in the 

Project Area 

Potential Impacts 

Western pond turtle 
(Clemys marmorata ) 

SC 

- 

The project area is within the historic range 
of the western pond turtle. This species is not 
currently found in urbanized portions of the 
Santa Clara Valley and is not expected in the 
project area. 

No 

None 

Swainson’s hawk 

(Buteo swainsoni) 

ST 

- 

The project area is within the historic range 
of Swainson’s hawk. The current range is 
limited to the Central Valley, California (UC 
Davis 2007). Swainson’s hawk is not 
expected to be in the project area. 

No 

None 

Bay checkerspot 
butterfly 
[Euphydryas editha 
bayensis ) 

FT 

No 2 

The Bay checkerspot butterfly is a medium 
sized butterfly. Historically, it occurred from 
the San Bruno Mountains, Mount Diablo, and 
Coyote Reservoir in the San Francisco Bay 
region (USFWS 2009b). Currently, it is 
restricted to areas of Santa Clara County in 
hills (USFWS 2009b) outside of the urban 
project area. 

No 

None 

Zayante band-winged 
grasshopper 
(Trimerotropis infantilis ) 

FE, CH 

No 

The Zayante band-winged grasshopper is is 
restricted to sandy soils in the Santa Cruz 
Mountains, Santa Cruz, California (USFWS 
1998). The project area does not provide 
suitable habitat. 

No 

None 

Central California 

Coastal steelhead DPS 

FT, CH 

No 

The central California coast steelhead 
includes coastal populations of winter 

Yes 

Yes 


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Table 21 Special Status Species with the Potential to be Present in the Vicinity of the Action Area 1 

Species 

Status 

Critical 

Habitat 

Present in 

the Action 

Area 

Distribution and Habitat Preference 

Potential to 

be Present 

in the 

Project Area 

Potential Impacts 

(Oncorhynchus mykiss ) 



steelhead from the Russian River south to 

Aptos Creek in Santa Cruz County. Trout in 
streams that are tributaries to San Francisco 
and San Pablo Bays are also included because 
rainbow trout are considered freshwater 
steelhead (NMFS2010). 

Steelhead are known to be present in the 
Guadalupe River. One juvenile steelhead was 
removed and relocated in 2012 during Reach 
10B dewatering monitoring and fish removal. 



Metcalf Canyon jewel- 
flower 

(.Streptanthus albidus 
ssp. albidus ) 

FE 

- 

Metcalf Canyon jewel-flower is an annual 
herb in the mustard family. It is pale green 
leaves with bristly hairs. It flowers from April 
to June. This plant is only found in the Coyote 
Valley area, outside of the project area 
(USFWS 2013). 

No 

None 

Santa Clara Valley 
dudleya 

[Dudleya abramsii ssp. 
setchellii ) 

FE 

- 

Santa Clara Valley dudleya is a low-growing 
perennial of the stonecrop family with fleshy 
leaves. It flowers from May to June and 
grows roots that are at least 6 inches long and 
often extend into rock crevices of the 
serpentine outcrops. It co-occurs with 

Metcalf Canyon jewel-flower in the Coyote 
Valley area (USFWS 2013). 

No 

None 


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Table 21 Special Status Species with the Potential to be Present in the Vicinity of the Action Area 1 

Species 

Status 

Critical 

Habitat 

Present in 

the Action 

Area 

Distribution and Habitat Preference 

Potential to 

be Present 

in the 

Project Area 

Potential Impacts 

Robust spineflower 
(Chorizanthe robusta var. 
robusta) 

FE, CH 

No 

Robust spineflower is a short-lived annual 
plant in the buckwheat family. It has a 
limited population size and range, occurring 
in 11 populations over a range of 21 miles in 
sandy soils along the coast in Santa Cruz 
County, California (USFWS 2010). It is not 
present in the project area. 

No 

None 

Contra Costa 
goldfields 
(Lasthenia conjugens) 

FE, CH 

No 

Contra Costa goldfields is an annual flowering 
plant in the aster family. It grows up to 12 
inches tall with branched stems. It has a 
daisy-like flower that blooms from March 
through June. It is found in vernal pools, 
swales, moist flats, and depressions in 
grassland habitats (USFWS 2008). It is not 
found in the project area. 

No 

None 

Notes: 

1 A USFWS online listed species query was conducted in April 2014. 

2 USFWS Critical Habitat MaDDer. Available at: httD://ecos.fws.eov/crithab/. Accessed on 15 Am'il 2015. 

FE - federal endangered 

FT - federal threatened 

SE - state endangered 

ST - state threatened 

CH - critical habitat 

SC - state species of concern 


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Significance Criteria: The project would have a significant impact if it would: 

• Result in a substantial loss of riparian forest or SRA cover that would not reestablish within 
10 years following construction (e.g., planted riparian forest does not establish within the 
project site and does not result in recruits of additional riparian vegetation], 

• Result in fish and wildlife avoiding the project area following establishment of riparian 
forest and SRA cover. 

• Result in take of listed species that could not be mitigated. 

• Result in take of a Migratory Bird Treaty Act (MBTA] protected bird. 

3.5.3 Potential Impacts and Mitigation Measures 

Clearing (and in some cases grubbing] of approximately 5 acres and excavating approximately 1.2 
acres of floodplain benches would remove urban forest, riparian forest, and SRA cover, as well as 
exotic trees, emergent aquatic vegetation, and other land cover types. Additionally, proposed 
removal of exotic vegetation would remove some non-native riparian plants within the reach. 

Table 22 provides an overview of the land cover types and habitat affected by the proposed action. 

It details the area of the existing land cover and habitat types, existing SRA cover and the total area 
of construction impacts within the reach. It further breaks down the total impacts into the footprint 
of impacts within the SRA cover zone (i.e., 15 feet from the low flow channel] and outside of the 
SRA cover zone. As shown, the proposed project would remove approximately 0.51 acre of native 
riparian forest (oak/sycamore woodland, willow/cottonwood/alder riparian forest, and riparian 
scrub], 0.16 acres of exotic trees, 0.001 acre of emergent wetland, as well as affecting other exotic 
shrub and herbaceous habitat types and open water. The project would also remove approximately 
387 linear feet of SRA cover. Not all impacts to the various land cover types listed below would 
require mitigation (e.g., pavement, open space, open water, and spot removal of exotics would not 
require mitigation]. Figure 19 and Figure 20 show the locations of the proposed vegetation 
removal (i.e., land cover class and habitat impact] within the reach. 

Table 23 provides details of the impact habitat which would require mitigation. As shown, 
approximately 387 linear feet of SRA cover and 0.51 acres of riparian forest (approximately 5 
percent of the total riparian forest] must be mitigated. Approximately 0.65 acres of exotic woody 
vegetation would require mitigation. Impacts to approximately 0.001 acre of emergent wetland 
would not require mitigation because placement of gravel at various locations in the low-flow 
channel is expected to create suitable areas for growth of additional aquatic emergent wetland. 


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Table 22 Impacts to Land Cover (Habitats) 

Land Cover Class 

(Habitat) 

Total Existing Area 1 
(acre) 

Total 

Habitat Impacts 
(acre) 

Herbaceous Ruderal 

8.80 

2.07 

Oak / Sycamore 
Woodland 

1.63 

0.30 

Willow / Cottonwood / 
Alder Riparian Forest 

7.83 

0.18 

Emergent Aquatic 

0.415 

0.001 

Exotic Trees 

0.95 

0.16 2 

Open* 

8.44 

0.29 

Other Exotic 

0.80 

0.49 2 

Pavement * 

0.88 

0.02 

Riparian Scrub 

0.63 

0.03 

Water * 

1.74 

1.50 

SRA cover 

-- 

386.91 

linear feet 

Notes: 

iTotal existing area includes all habitats within the footprint of the project area. 

2 An additional 0.18 acre of exotic trees removal and 0.90 acre of "other exotics" removal would consist of spot 
removals of individuals. Such spot removals will not be considered a habitat impact by the RWQCB for purposes of 
mitigation accounting. 

* Cover/habitat types are not considered riparian forest or SRA cover and would not require mitigation. Emergent 
aquatic habitat is not included in this note. The draft EA incorrectly counted several cover classes as riparian 
forest. 


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Legend 


Vegetation Removal Areas 


Land Cover Classes 


Herbaceous ruderal 


Oak/Sycamore Woodland 
Willow/Cottonwood/Alder Riparian Forest 
emergent aquatic 


exotic trees 


other exotic 


pavement 
riparian scrub 


water 


Low Flow Water Elevation Surface Level 


15-foot Buffer around Low Flow Water Level 


0.1 Miles 


Figure 19. Proposed Vegetation Removal (i.e., land cover and habitat impacts) in the Upstream Portion of Reach 12 


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Legend 

Vegetation Removal Areas 

Esa 

Land Cover Classes 

Herbaceous ruderal 
Oak/Sycamore Woodland 
Willow/Cottonwood/Alder Riparian Forest 
emergent aquatic 
exotic trees 
open 

other exotic 
pavement 
riparian scrub 
water 

Low Flow Water Elevation Surface Level 

15-foot Buffer around Low Flow Water Level 


Figure 20. Proposed Vegetation Removal in the Downstream Portion of Reach 12. Some removal areas along the east edge (adjacent to houses) would be smaller than shown. 


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Table 23 Habitat and Vegetation Mitigation Requirements 


Land Cover Class 
(Habitat) 

Total Habitat 
Impacts 
(acre) 

Federal 

Compensation 

Ratio 1 

RWQCB 

Compensation 

Ratio 2 

Total RWQCB 
Mitigation Required 
(acre) 

Oak / Sycamore 
Woodland 

0.30 

1:1.85 

2:1 

1.02 

Willow / 
Cottonwood / 
Alder Riparian 
Forest 

0.18 

1:1.85 

2:1 

Riparian Scrub 

0.03 

1:1.85 

2:1 

Riparian Forest Mitigation 

2:1 

1.02 

Exotic Trees 

0.163 

1:1 

1:1 

0.16 

Other Exotic 

0.49 3 

1:1 

1:1 

0.49 

Urban Forest Miti 

gation 

1:1 

0.65 

SRA Cover 

(linear feet) 

386.91 

1:1 

1:1 

386.91 

SRA Cover Mitigation 

1:1 

386.91 

linear feet 

Emergent 

Aquatic 4 

0.001 

1:1 

1:1 

0.001 


Notes: 

1 Compensation ratio taken from the 2007 Congressionally-authorized Local Preferred Plan and is for NEPA evaluation of 
mitigation. 

2 From Order R2-2003-0115 (RWQCB, December 16, 2003. 

3 An additional 0.18 acre of exotic trees and 0.09 acre of other exotic consists of spot removals of individuals or very small 
clusters which would not need to be actively mitigated. 

4 Placement of gravel at various locations in the low-flow channel is expected to create suitable areas for growth of additional 
aquatic emergent wetland which is expected to mitigate this impact. 


Table 24 describes the vegetation replanting proposed for the project. It discusses the various 
planting zones proposed (i.e., streamside, instream, lower floodplain, upper floodplain, upland, and 
hydroseeding zones). It also discusses the planting palette (i.e., species) proposed to be planted 
within each zone. Finally, it discusses the planting zone equivalent. The planting zone equivalent 
provides a method of converting each planting zone into one of the impacted existing habitat types. 
It is the planting zone equivalent area that will be used to determine mitigation for habitat impacts. 


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Table 24 Proposed Planting Zones and Palettes and Mitigation 

Equivalent 

Planting 

Zone 

Description 

Proposed Planting Palette 

Planting Zone 
Equivalent 

Streamside 

planting 

zone 

Plantings within 15 feet of 
the low follow stream bank. 

Provides SRA cover. 

White alder ( Alnus rhombifolia ) 

Fremont cottonwood [Populus fremontii) 
Valley oak ( Quercus lobata) 

Red willow ( Salix laevigata ) 

Arroyo willow ( Salix lasiolepis) 

Mule fat [Baccharis salicifolia) 

California wild rose ( Rosa caiifornica ) 
California blackberry ( Rubus ursinus ) 
Narrow-leaved willow ( Salix exigua) 

Virgin’s bower ( Clematis ligusticifolia ) 

Streamside 

planting 

Instream 

planting 

zone 

Plantings on instream 
structures. Provides SRA 

cover. 

Red willow ( Salix laevigata ) 

Arroyo willow [Salix lasiolepis ) 

Mule fat [Baccharis salicifolia) 

Narrow-leaved willow [Salix exigua ) 

Streamside 

planting 

Lower 

floodplain 

planting 

and 

seeding 

zone 

Plantings on lower 
floodplain area that would 
be seasonally inundated. 
Distance from channel 
varies by location. 

Fremont cottonwood [Populus fremontii) 
Valley oak [Quercus lobata ) 

Red willow [Salix laevigata) 

Arroyo willow [Salix lasiolepis) 

Narrow-leaved willow [Salix exigua) 

Mugwort [Artemisia douglasiana) 

Oregon false goldenaster [Heterotheca 
oregona var. scaberrima) 

Creeping wildrye [Leymus triticoides) 
California man-root [Marah fabaceus) 

Oak / Sycamore 
Woodland 

Upper 

floodplain 

planting 

and 

seeding 

zone 

Plantings on upper 
floodplain surfaces and low 
channel bank elevations. 
Areas would only be 
inundated during high flow 
events. Distance from 
channel varies by location. 

California buckeye [Aesculus caiifornica) 

Coast live oak [Quercus agrifolia) 

Valley oak [Quercus lobata) 

Mugwort [Artemisia douglasiana) 

Oregon false goldenaster [Heterotheca 
oregona var. scaberrima) 

Creeping wildrye [Leymus triticoides) 
California man-root [Marah fabaceus) 

Oak / Sycamore 
Woodland 

Upland 

planting 

zone 

Plantings on upper banks 
and high terrace, beyond 
the top of channel bank. 

This zone would not be 

California buckeye [Aesculus caiifornica) 

Coast live oak [Quercus agrifolia) 

Valley oak [Quercus lobata) 

Oak / Sycamore 
Woodland 


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Table 24 Proposed Planting Zones and Palettes and Mitigation 

Equivalent 

Planting 

Zone 

Description 

Proposed Planting Palette 

Planting Zone 
Equivalent 


inundated. Due to the 

width of this reach and the 

locations of the berms, this 

zone is limited. 

California sagebrush ( Artemisia californica ) 

California brome ( Bromus carinatus) 

Purple needlegrass ( Stipa pulchra ) 


Special 

Upland 

Planting 

Zone 

Similar to the upland 
planting zone, but with 
fewer shrubs and with 
plant species selected for 
somewhat greater fire 
resistance. 

Coast live oak ( Quercus agrifolia) 

Valley oak ( Quercus lobata) 

Blue elderberry [Sambucus caerulea) 

Bush monkeyflower [Mimulus aurantiacus) 
California coffeeberry [Rhamnus californica) 
Catalina currant [Ribes viburnifolium] 

Wooly blue curls [Trichostema lanatum] 
Yarrow ( Achillea millefolium] 

California fuschia ( Epilobium canum] 

Oak / Sycamore 
Woodland and 

Urban Forest 

Hydroseed 

zone 

Limited hydroseeding on 
newly constructed berm 
slopes and other disturbed 
sites for erosion control. 

No woody plants or vines 
would be planted here. 

Sterile non-invasive grasses 

Hydroseeding 


Figure 21 shows the location of the various planting zones within the reach. The location of each 
zone relative to the channel depends on the overall width of the reach in any respective location. 
Figures 22 and 23 show the locations of the proposed replanting in Reach 12. Upland planting 
zones are only proposed for limited downstream areas due to constraints. Upland planting zones 
are not shown on Figure 21; however, they are identified in Figure 23. Table 25 and Table 26 show 
the amount of mitigation for each planting zone equivalent. As shown, the proposed planting would 
result in 2.22 acres of new riparian forest and 658.26 linear feet of SRA cover. 


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Figure 22. Proposed Replanting in the Upstream Portion of Reach 12 


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N 




F«r ViJ 


* ■»-. 


r\ 




* 


Legend 

Low Flow Water Elevation Surface Level 


m 


r ' Mk 


5> 


If 


!* 


> 


15-foot Buffer around Low Flow Water Level 


V 






** 




Vegetation Replanting 

Herbaceous Ruderal 
Oak/Sycamore Woodland 


*r 






s 




Willow/Cottonwood Alder Riparian Forest 






*T 




Vi 




Ml 






Upland Planting 


Zone 




- 








- 






Match Line 


I 








0.025 0.05 

1 I I I I I 


0.1 Miles 






Figure 23. 


Proposed Replanting in the Downstream Portion of Reach 12. An additional 0.25 acre of upland and special upland plantings would be made on the east bank but are not shown. 


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Table 25 Proposed Vegetation Replanting Mitigation 

Habitat Type 

Planting Zone 
Equivalent 

Total Planting (acre) 

Oak Woodland 1 

Lower floodplain 

Upper floodplain 

Upland planting 

Special upland planting 

2.02 

Willow / Cottonwood / 
Alder Riparian Forest 

Streamside planting 

0.20 

TOTAL RIPARIAN FOREST PLANTED 

2.22 

Herbaceous Ruderal 2 

Hydroseeding 

2.13 

Notes: 

1 Sycamore will not be planted at this time due to genetic issues with wild seed in Santa Clara County. 
Evergreen and deciduous oaks will be substituted. 

2 Herbaceous ruderal (hydroseeding) does not count towards riparian forest. This habitat type will not 
be discussed further in this document. 


Table 26 Proposed SRA Cover Replanting 

Mitigation 

Habitat Type 

Total Planting 
(linear feet) 

Riparian Forest Planting 

Riparian forest planting within 15 
feet of low-flow channel 

207.26 

Instream Structures 

Debris jam 
(9 total) 

225 

Root wad 

(15 total) 

192 

Undercut bank 

(7 total) 

34 

Total 

658.26 


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Finally, Table 27 shows the habitat impacts and proposed mitigation calculations for the proposed 
Reach 12 project. It provides total mitigation required for riparian forest loss within the SRA cover 
zone and outside this zone, and provides the net difference. The table shows that: 


• The impact to riparian forest 0.51 acre, and to exotic trees and shrubs 0.65 acre. The 
riparian forest mitigation planting would be 2.22 acres, for a net increase of 1.02 acre. 

• The impact to SRA cover is approximately 387 linear feet. The proposed mitigation planting 
would be 658.26 linear feet, for a net increase of 271.35 linear feet. 


Table 27 

Habitat Impact and Proposed Mitigation Calculations 

Land Cover Class 

(Habitat) 

Total 

Mitigation 

Required 

Proposed 

Mitigation 

Planting 

Difference 

Riparian Forest 1 
(acre) 

1.02 

1.57 

+0.55 

Urban Forest 2 

0.65 

0.65 

0.00 

SRA Cover 3 

(linear feet) 

386.91 

658.26 

+271.35 

Notes: 

1 Proposed planting of oak/sycamore woodlands and willow/cottonwood/alder riparian forest is intended as 
mitigation for riparian forest loss. 

2 Urban forest consists of generally non-native trees and shrubs within the riparian forest and near the edge of the 
project right-of-way. 

3 SRA cover includes riparian forest within 15 feet of the low-flow channel, measured in linear feet parallel to the 
channel bank, as well as wood debris and undercut banks that provide aquatic cover. 


Impact BIO-1: Result in a substantial loss of riparian forest or SRA cover that would not reestablish 
within 10 years following construction. Construction of the proposed Reach 12 project would result 
in a net increase of 1.02 acre of riparian forest and 271.35 linear feet of SRA cover. It is expected 
that riparian forest and SRA cover protected during construction (. Avoidance and Minimization 
Measure BIO-1), as well as vegetation planted within the riparian forest and SRA cover zones 
[Mitigation Measure BIO-2) would, over time, contribute to additional riparian forest and SRA cover. 
Protected riparian forest and SRA cover would encourage recruitment of trees and shrubs in 
impacted areas. Planted vegetation would take time to establish and become suitable riparian 
forest and SRA cover; but, ongoing maintenance and monitoring of the vegetation would ensure 
that establishment is successful. Further, should planted vegetation not be successful, unsuccessful 
areas would be replanted and closely monitored. As described in Avoidance and Minimization 
Measure BIOS, the USACE and SCVWD would also update the 1999 MMP for Reach 12. Mitigation 


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maintenance, monitoring, report would closely follow the revised MMP. Should replanting not 
meet the success criteria identified in a revised MMP, remediation measures would be taken. 

Implementation of the above listed avoidance, minimization, and mitigation measures ( BIO-1, BIO- 
2, and BIO-3 ] would ensure that this impact is less than significant. 

Impact BIO-2: Result in permanent loss of wetlands or other waters of the United States. The 
proposed project would result in a temporary loss of 0.001 acre of aquatic emergent vegetation. 
However, following construction it is expected that aquatic emergent vegetation would reestablish 
at the margins of the channel. Adding gravel to the river would create additional shallow water 
habitat that would encourage localized areas of emergent aquatic vegetation in the short term. In 
the long term, with or without the proposed action, emergent aquatic vegetation will tend to be 
replaced with SRA cover due to development of continuous shade along the river banks. Therefore, 
this impact is expected to be less than significant. Implementing Avoidance and Minimization 
Measure BIO-3: Update and revise the 1999 MMP would provide for monitoring future 
establishment of aquatic emergent vegetation. 

Impact BIO-3: Result in fish and wildlife avoiding the project area following establishment of 
riparian forest and SRA cover. Though unlikely, following construction there is a potential for fish 
and wildlife to avoid the project area. As previously mentioned, nearly all riparian forest and SRA 
cover would be protected from construction activities. Fish and wildlife would be able to use this 
suitable habitat shortly after construction. Following construction, the improved channel 
morphology and growth of planted vegetation would provide additional suitable habitat for species. 
As such, it is expected that this impact would be less than significant. Further, wildlife monitoring 
would be included in the revised MMP [see Avoidance and Minimization Measure BIO-3)-, this would 
provide information to assess is the project results in fish and wildlife avoiding the area. 

Impact BIO-4: Result in take of listed species that could not be mitigated. The only listed species 
that has the potential to be present in the project area is the federally-threatened Central California 
Coastal steelhead. As previously discussed, one juvenile steelhead was captured and relocated 
downstream during the 2012 dewatering of Reach 10B for construction. There is the potential that 
dewatering could result in harm to steelhead that may be present in Reach 12. Prior to dewatering, 
a qualified and approved biologist would be onsite to capture and relocate native fish downstream 
of construction activities (see Avoidance and Minimization Measure BIO-4). Relocating native fish 
would likely reduce the potential for take of listed steelhead. Should take of steelhead occur, 
individuals would be preserved and the NMFS would be contacted immediately. Additionally, a 
qualified biologist would be onsite to monitor dewatering activities periodically during 
construction and during re-watering the channel. Habitat improvements included in the proposed 
action would improve steelhead trout habitat in the medium and long term. Monitoring and 
relocating native fish would ensure that impacts to native fish, including steelhead, are less than 
significant. 


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Impact BIO-5: Result in take of protected birds or their nests. Several birds inhabit the riparian and 
aquatic habitat in the project area. Take of birds or their nests could result in adverse effects. Prior 
to the start of construction, but no earlier than 1 week prior to construction, a qualified biologist 
would monitor the project site for nesting birds. Additionally, monitoring would be conducted 
periodically during construction. As discussed in Avoidance and Minimization Measure BIO-5, 
should protected nests be identified, they would be protected by a 50-foot clearance. Active 
swallow nests under bridges would be monitored to ensure that construction activities do not harm 
nesting. Implementation of Avoidance and Minimization Measure BIO-5 would ensure that impacts 
to protected birds are less than significant. 

Avoidance and Minimization Measures 

Avoidance and Minimization Measure BIO-1: Vegetation not proposed for removal would be 
protected during construction. All vegetation not proposed for removal would be clearly marked 
and fenced off such that it is protected at all times from construction activities. During 
construction, an approved arborist would be onsite at all times to monitor the health of the 
protected vegetation. Should protected vegetation show signs of distress, appropriate measures 
would be taken to alleviate stressed individuals and restore health. 

Mitigation Measure BIO-2: Replant vegetation according to the planting designs for the project. 

The proposed project would involve planting approximately 2.22 acres of riparian vegetation. Of 
this 207 linear feet would contribute to SRA cover. This vegetation would mitigate all impacts to 
riparian forest, urban forest, and SRA cover. 

Following construction, the planted vegetation would be maintained for a minimum of 4 years. 
Further it would be monitored annually for a period up to 12 years, depending on the requirements 
of the MMP (see Avoidance and Minimization Measure BIO-3). 

Mitigation Measure BIO-3: Update and revise the 1999 MMP. While the 1999 MMP would be in 
force initially, the USACE and SCVWD would seek to update this MMP for Reach 12 at a later date in 
coordination with the resource agencies via the AMT process. The updated MMP would identify 
maintenance that would help ensure success of the planted vegetation as well as goals and success 
criteria for vegetation and habitats. It would describe monitoring and reporting requirements. 
Finally, it would prescribe vegetation and habitat rehabilitation and replanting measures, should 
the goals of the mitigation plantings not be met. The MMP would be designed to coordinate with 
mitigation and monitoring activities in other reaches. 

Avoidance and Minimization Measure BIO-4: Monitor and relocate native fish during dewatering 
activities. Prior and during dewatering activities, a qualified fish biologist would be onsite to 
monitor for native fish. Should native fish be identified, they would be captured and relocated 
downstream to areas not affected by dewatering activities. Non-native fish would be disposed of. 
Should a steelhead be taken during dewatering activities, the biologists would safely relocate 


Upper Guadalupe Flood Control Project, Reach 12 

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individual fish and contact the USACE and NMFS. All fish monitoring and relocation activities 
would be recorded and results would be provided to the NMFS. 

Prior to the start of any construction (including upland construction], a fish monitoring and 
relocation plan would be prepared. The plan would detail all monitoring and relocation activities, 
as well as recording and reporting practices. This plan would be submitted to the NMFS for review 
and approval. (Note: this plan would be prepared by the contractor selected to construct the 
project.] 

Avoidance and Minimization Measure BIOS: Conduct bird surveys prior to construction. 
Construction activities occurring from February 1 through August 31 would require bird surveys 
prior to construction. A qualified and approved biologist would be responsible for conducting bird 
surveys and ensuring adequate protection of a 50-foot buffer around each nest from all 
construction activities. The biologist would train construction personnel of the 50-foot protection 
requirement. Additionally, the biologist would periodically monitor bird activity and look for new 
nests within the project area. 

Swallow nests under the freeway overpasses would be less than 50 feet away from construction 
traffic. Coordination with the USFWS and the CDFW resulted in concurrence that careful 
monitoring of nesting bird activity during construction would be the best mitigation approach. 
Removal of nests and placement of exclusionary netting has proved to be risky and 
counterproductive on other projects faced with similar nesting activity. 

Prior to the start of any construction, a bird monitoring and protection plan would be prepared. 
The plan would detail all monitoring and relocation activities, as well as recording and reporting 
practices. The plan would be submitted to the USACE for approval. (Note: this plan would be 
prepared by the contractor selected to construct the project.] 

3.6 Air Quality 

The project is located in the South Bay in Santa Clara County, within the San Francisco Bay Area Air 
Basin (air basin]. The air basin covers an area of approximately 5,540 square miles and is 
characterized by complex terrain of coastal mountain ranges, inland valleys, and the San Francisco 
Bay. The air basin is generally bounded on the west by the Pacific Ocean, on the north by the Coast 
Ranges, and on the east and south by the Diablo Range. 

The climate is dominated by the strength and location of a semi-permanent, subtropical high- 
pressure cell over the northeastern Pacific Ocean. The climate is also affected by the moderating 
effects of the adjacent oceanic heat reservoir. Mild summers and winters, moderate rainfall, 
daytime onshore breezes, and moderate humidity characterize regional climatic conditions. In 
summer, when the high-pressure cell is strongest and farthest north, fog forms in the morning and 
temperatures are mild. In winter, when the high-pressure cell is weakest and farthest south, 
occasional rainstorms occur. 


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Regional flow patterns affect air quality patterns by directing pollutants downwind of sources. 
Localized meteorological conditions, such as moderate winds, disperse pollutants and reduce 
pollutant concentrations. When a warm layer of air traps cooler air close to the ground, an 
inversion layer is produced. Such temperature inversions hamper dispersion by creating a ceiling 
over the area and trapping air pollutants near the ground. During summer's longer daylight hours, 
plentiful sunshine provides the energy needed to fuel photochemical reactions between nitrogen 
oxides (NOx] and reactive organic gases (ROG], which result in ozone formation. 

In the winter, temperature inversions dominate during the night and early morning hours but 
frequently dissipate by afternoon. At this time, the greatest pollution problems are from carbon 
monoxide (CO] and NOx. High CO concentrations occur on winter days with strong surface 
inversions and light winds. CO transport is extremely limited. 

The federal Clean Air Act [CAA] established the National Ambient Air Quality Standards (NAAQS] 
for pollutants considered harmful to public health and the environment. These criteria pollutants 
are ozone (O3), carbon monoxide [CO], nitrogen dioxide (NO 2 ), particulate matter less than 10 
microns in diameter (PM10], particulate matter less than 2.5 microns in diameter (PM2.5], lead 
[Pb], and sulfur dioxide (SO 2 ]. California Clean Air Act [CCAA] also established the California 
Ambient Air Quality Standards (CAAQS) for criteria pollutants. In general, CAAQS are more 
stringent than the NAAQS. 

The CAA requires states to classify air basins as either attainment or nonattainment with respect to 
quantitative thresholds in the NAAQS, and prepare State Implementation Plans (SIPs], SIPs 
articulate emission reduction strategies to maintain the NAAQS for those areas designated as 
attainment and to attain the NAAQS for those areas designated as nonattainment. 

The project area is within the geographical jurisdiction of the Bay Area Air Quality Management 
District (BAAQMD], The attainment status of NAAQS and the CAAQS are shown in Table 28. Since 
the BAAQMD is not in attainment for all pollutants, the BAAQMD has adopted emission threshold 
guidelines required to attain federal and state ambient air quality standards in the Bay Area as part 
of the SIP. BAAQMD has daily construction emission thresholds for ROG, NOx, PM10 and PM2.5. 
Furthermore, BAAQMD has annual construction emission threshold for green house gasses [GHGs]. 
The applicable construction emission guidelines are shown in Table 29. 

Furthermore, ah federal actions in nonattainment or maintenance areas that have the potential to 
emit criteria pollutants or their precursors for which the area is designated nonattainment are 
required to evaluate whether estimated emissions conform to the SIP. That is, the federal action 
must be consistent with the SIP’s purpose of eliminating or reducing the severity and number of 
violations of the NAAQS and achieving expeditious attainment of those standards. The General 
Conformity Rule is not applicable to federal actions where estimated emissions are below de 
minimis levels (Table 30], 


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Table 28 Ambient Air Quality Attainment Status 


Criteria 

Pollutant 

Averaging 

Time 

California Standards 

National Standards 

Concentration 

Attainment 

Status 

Concentration 

Attainment 

Status 

Ozone (O 3 ) 

8 Hour 

0.070 ppm 

Nonattainment 

0.075 ppm 

Nonattainment 

1 Hour 

0.09 ppm 

Nonattainment 



Carbon 

Monoxide 

(CO) 

8 Hour 

9.0 ppm 

Attainment 

9 ppm 

Attainment 

1 Hour 

20 ppm 

Attainment 

35 ppm 

Attainment 

Nitrogen 

Dioxide 

(N0 2 ) 

1 Hour 

0.18 ppm 

Attainment 

0.100 ppm 

Unclassified 

Annual 

Arithmetic 

Mean 

0.030 ppm 

- 

0.053 ppm 

Attainment 

Sulfur 

Dioxide 

(S0 2 ) 

24 Hour 

0.04 ppm 

Attainment 

0.14 ppm 

Attainment 

1 Hour 

0.25 ppm 

Attainment 

0.075 ppm 

Attainment 

Annual 

Arithmetic 

Mean 

- 

- 

0.030 ppm 

Attainment 

Particulate 

Matter 

(PM10) 

Annual 

Arithmetic 

Mean 

20 ug/m 3 

Nonattainment 

- 

-- 

24 Hour 

50 ug/m 3 

Nonattainment 

150 ug/m 3 

Unclassified 

Particulate 

Matter 

(PM2.5) 

Annual 

Arithmetic 

Mean 

12 ug/m 3 

Nonattainment 

12 ug/m 3 

Attainment 

24 Hour 

- 

- 

35 ug/m 3 

Nonattainment 

Sulfates 

24 Hour 

25 ug/m 3 

Attainment 

- 

-- 

Lead (Pb) 

30 day 
Average 

1.5 ug/m 3 

- 

- 

-- 

Calendar 

Quarter 

- 

- 

1.5 ug/m 3 

Attainment 

Rolling 3 
Monthly 
Average 

- 

- 

0.15 ug/m 3 


Hydrogen 

Sulfide 

1 Hour 

0.03 

Unclassified 

- 

-- 

Vinyl 

Chloride 

24 Hour 

0.010 ppm 

- 

- 

-- 

Visibility 

8 Hour 

- 

Unclassified 

- 

-- 


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Table 28 Ambient Air Quality Attainment Status 

Criteria 

Pollutant 

Averaging 

Time 

California Standards 

National Standards 

Concentration 

Attainment 

Status 

Concentration 

Attainment 

Status 

Reducing 

Particles 

(10:00 to 
18:00 PST] 





NOTES: 

1 Source: http://hank.baaqmd.gov/pln/air_quality/ambient_air_quality.html 


Table 29 BAAQMD Construction Emissions 

Thresholds 

Criteria Pollutants, 
Precursors, Odors 

and GHGs 

BAAQMD Construction Emission 

Thresholds 

VOC 

54 (lb/day) 

N0 2 

54 (lb/day) 

PM10 

82 (lb/day) 

PM2.5 

54 (lb/day) 

Pb 

None 

(Implement BMPs) 

CO 

None 

(Implement BMPs) 


Table 30 General Conformity Rule 

de minimis Thresholds 

Criteria Pollutant 

Thresholds 

(tons/year) 

VOC 

10 

NOz 

10 

PM10 

70 

PM2.5 

100 

Pb 

25 

CO 

100 


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Significance Criteria: The project would have a significant effect on air quality if estimated 
construction emissions exceed applicable BAAQMD construction emissions thresholds or the 
General Conformity de minimis thresholds. 

3.6.1 Potential Impacts and Mitigation Measures 

The project encompasses several major elements phased from 2014 thru 2018: clearing and 
grubbing, channel modification, raising berms, construction of maintenance roads and access 
ramps, and vegetation maintenance. Table 11 (Section 2.11] provides a summary of proposed 
construction activities in Reach 12. Though some vegetation would occur in 2014, the majority of 
construction would occur in 2015. Project elements in 2016 thru 2018 would entail maintenance of 
planted vegetation. In-channel construction would occur from June thru October 2015. In general, 
approximately eight pieces of off-road construction equipment would be utilized periodically as 
needed for the duration of construction. Off-road construction equipment includes an excavator, 
loader, dozer, crane, soil stabilizer, grader, roller, and a water truck. Duration of use for each piece 
of off-road equipment by construction phase is shown in Appendix C. Construction would be 
limited to 8-hour working days. Major project elements expected to affect air quality are further 
described below. 

• Clearing and grubbing entail the use of an excavator, loader, and dozer to clear (and in some 
cases, grub] within the 5-acre footprint between August and November of 2014. Duration 
of use for each piece of off-road equipment is shown in Appendix C. Up to 12,300 cubic 
yards of vegetation would be transported to Kirby Canyon Landfill or Guadalupe Landfill. 
Both landfills are within a 20-mile radius of the project site. Furthermore, grubbing would 
require up to 18 inches of topsoil from the 5-acre footprint to be removed. As a result, 
approximately 4,100 cubic yards of soil would also be transported to landfills, requiring 
approximately 1,640 haul trips in total for the clearing and grubbing operations. 

• Channel modification activities encompass creation of flood benches, installation of 
instream structures, and gravel augmentation. These activities require the periodic use of 
excavator, dozer, crane, grader, roller, soil stabilizer, and water trucks over a five-month 
period. Duration of use for each piece of off-road equipment is shown in Appendix C. 

Gravel import would require 608 haul trips. Import of fill for flood bench work and 
instream structures would require 175 haul trips. 

• Construction of maintenance road and access ramps would occur in 2015, subject to 
seasonal restrictions on construction activities. These activities require the periodic use of 
excavator, dozer, crane, grader, roller, soil stabilizer, and water trucks. Duration of use for 
each piece of off-road equipment is shown in Appendix C. Approximately 253 haul trips 
would be required to import aggregate. 

• Raising existing berms would take place during a 1.5 month window between June and 
October 2015. These activities require the periodic use of excavator, dozer, crane, grader, 


Upper Guadalupe Flood Control Project, Reach 12 

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Page 121 




roller, soil stabilizer, and water trucks. Duration of use for each piece of off-road equipment 
is shown in Appendix C. No additional haul trips are required. 

Construction emissions for the proposed project were estimated using CalEEMod version 2013.2.2. 
Input data and parameters, such as construction schedule, phasing, and equipment usage were 
derived from construction cost estimates and project construction schedule. Daily emission 
estimates were compared to BAAQMD construction emission thresholds. Annual emission 
estimates were compared to the General Conformity Rule de minimis thresholds. Note that 
calculations substantially overstate emissions since some previous project elements were deleted 
after calculations were completed. 

Daily emission estimates for all years of construction are shown in Table 31. With the exception of 
NOx emissions in 2015, unmitigated emission estimates for all regulated pollutants were below 
daily construction thresholds for all construction years. Emissions of NOx in 2015 were estimated 
to be 105.8 lb/day which surpassed the BAAQMD NOx threshold of 54 lb/day. Use of Tier 4 engines 
as mitigation would reduce 2015 NOx emissions below the 54 lb/day NOx threshold to 22.83 
lb/day. Furthermore, use of watering trucks resulted in reductions of fugitive PM10 and PM2.5. 

Annual emission estimates for all years of construction are shown in Table 32. Mitigated and 
unmitigated emissions for all construction years are below General Conformity de minimis 
thresholds. 

GHG emission estimates for all years of construction are shown in Table 33. GHG emissions for all 
construction years are below BAAQMD GHG emissions thresholds. Note that the "mitigation" 
numbers are likely to be conservative (biased upwards relative to actual emissions], while the 
"mitigation" numbers are based on data from engines and are likely to not be biased in either 
direction. Therefore, the "mitigation" numbers are very unlikely to be exceeded if emissions are 
mitigated with Tier 4 engines. 


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Table 31 



Daily Construction Emissions Estimates 





Criteria 

Pollutants 

and 

BAAQMD 

Construction 

Emission 

Thresholds 

2014 Daily 
Construction 

Emissions 

(tons/year) 

2015 Daily 
Construction 

Emissions 

(tons/year) 

2016 Daily 
Construction 

Emissions 

(tons/year) 

2017 Daily 
Construction 

Emissions 

(tons/year) 

2018 Daily 
Construction 

Emissions 

(tons/year) 

Precursors 

(lb/day ) 1 

No 

Mitigation 2 

w/ 

Mitigation 23 

No 

Mitigation 2 

w/ 

Mitigation 2 ' 3 

No 

Mitigation 2 

w/ 

Mitigation 23 

No 

Mitigation 2 

w/ 

Mitigation 23 

No 

Mitigation 2 

w/ 

Mitigation 23 

ROG 

54 

4.73 

3.31 

9.42 

1.60 

0.95 

0.16 

0.87 

0.16 

0.77 

0.16 

NOx 

54 

50.95 

26.58 

105.8 

22.83 

10.86 

0.70 

9.84 

0.70 

8.29 

0.70 

CO 

None 

31.16 

43.44 

55.85 

55.89 

5.16 

6.00 

4.78 

5.99 

4.26 

5.98 

S0 2 

None 

0.04 

0.04 

0.08 

0.08 

0.13 

0.13 

0.13 

0.13 

0.13 

0.13 

PM 10 E 4 

82 

2.57 

1.37 

5.05 

0.41 

0.40 

0.02 

0.36 

0.02 

0.30 

0.02 

PM 2.5 E 

54 

2.3 

1.3 

4.6 

0.41 

0.37 

0.02 

0.33 

0.02 

0.27 

0.02 

PM 10 F5 

None 

12.14 

5.91 

13.03 

6.19 

0.05 

0.05 

0.01 

0.01 

0.01 

0.01 

PM 2.5 F 

None 

5.98 

2.80 

6.81 

3.15 

0.01 

0.01 

0.00 

0.00 

0.00 

0.00 

Notes: 

1 BAAQMD 2001 CEQA Guidelines, Table 2-1, Section 2-6 

2 The discrepancy between unmitigated and mitigated CO emissions is the different algorithms used to calculate emissions. Unmitigated emissions (including CO) are calculated based on actual engine 
test data. In contrast mitigated emissions are calculated using engine standards manufacturers are required to meet. Thus, actual mitigated emissions are almost certain to be lower than stated. 

3 Mitigation using Tier 4 engines for off-road equipment and use of water trucks. 

4 Emission 

5 Fugitive 


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Table 32 Annual Construction Emissions Estimates 

Criteria 

Pollutant 

General 

Conformity 

Rule 

de minimis 

Thresholds 

(tons/year) 1 

2014 Daily 
Construction 

Emissions 

(tons/year) 

2015 Daily 
Construction 

Emissions 

(tons/year) 

2016 Daily 

Construction Emissions 
(tons/year) 

2017 Daily 
Construction 

Emissions 

(tons/year) 

2018 Daily 
Construction 

Emissions 

(tons/year) 

No 

Mitigation 2 

w/ 

Mitigation 23 

No 

Mitigation 2 

w/ 

Mitigation 2 ' 3 

No 

Mitigation 2 

w/ 

Mitigation 2 ' 3 

No 

Mitigation 2 

w/ 

Mitigation 2 ' 3 

No 

Mitigation 2 

w/ 

Mitigation 23 

VOC 

10 

0.09 

0.05 

0.13 

0.33 

0.22 

0.00 

0.11 

0.00 

0.01 

0.00 

no 2 

10 

0.98 

0.49 

1.49 

0.37 

0.26 

0.17 

0.13 

0.00 

0.11 

0.00 

PM10 4 

70 

0.32 

0.16 

0.30 

0.12 

0.01 

0.00 

0.00 

0.00 

0.00 

0.00 

PM2.5 4 

100 

0.13 

0.08 

0.12 

0.06 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

Pb 5 

25 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

CO 

100 

0.60 

0.80 

0.77 

0.87 

0.12 

0.14 

0.06 

0.08 

0.05 

0.08 

Notes: 

1 General Conformity Rule (40 CFR § 93.153) 

2 The discrepancy between unmitigated and mitigated CO emissions is the different algorithms used to calculate emissions. Unmitigated emissions (including CO) are calculated based on actual engine test data. 

In contrast mitigated emissions are calculated using engine standards manufacturers are required to meet. Thus, actual mitigated emissions are almost certain to be lower than stated. 

3 Mitigation using Tier 4 engines for off-road equipment and use of water trucks. 

4 Total PM values (exhaust & fugitive) from CalEEMod 

5 CalEEMod does not provide estimates for Pb emissions since it is no longer used in formulating fuel. Thus, Pb values are 0.00 by default. 

Note that calculations overstate emissions since some work was deleted after calculations were completed. 


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Table 33 

Annual GHG Emissions Estimates 


Criteria 

Pollutant 

BAAQMD 

GHG 

Emission 

Thresholds 

(MT 

CCUe/year) 1 

2014 Annual 

GHG 

Emissions 
(MT COze/year) 2 

2015 

Annual GHG 

Emissions 

(MT 

C02e/year) 2 

2016 

Annual GHG 

Emissions 

(MT 

COze/year) 2 

2017 

Annual GHG 

Emissions 

(MT 

C02e/year) 2 

2018 Annual 

GHG 

Emissions 

(MT 

C02e/year) 2 

GHG 

1,100 

81.17 

112.44 

30.33 

16.77 

17.12 

NOTES: 

1 BAAQMD 2001 CEQA Guidelines, Table 2-1, Section 2-6 

2 Calculations overstate emissions due to some work being deleted after calculations were completed. 



Impact AQ-1: Estimated emissions exceed General Conformity de minimis thresholds. Annual 
construction emissions for all construction years are below General Conformity de minimis 
thresholds. Impacts to air quality would be less than significant. 

Impact AQ-2: Estimated emissions exceed applicable BAAQMD construction emissions thresholds. 
Emissions for NOx in 2015 would exceed BAAQMD construction emissions threshold of 54 lb/day. 
With the implementation of Avoidance and Minimization Measure AQ-1, estimated emissions for 
NOx would be below the BAAQMD construction emissions threshold, and impacts to air quality 
would be less than significant. 

Avoidance, Minimization, and Mitigation Measures 

Avoidance and Minimization Measure AQ-1: Utilize Tier-4 off-road equipment. Utilize off-road 
diesel-powered construction equipment that meets Tier-4 off-road emission standards 
(construction equipment is 2008 or newer] for all off-road equipment greater than 50 horsepower. 

General Conformity Rule Applicability: Construction emission would not exceed General 
Conformity de minimis thresholds. Therefore, a General Conformity analysis is not required. 

3.7 Historic and Cultural Resources 

The term cultural resource is used to describe the tangible and intangible evidence of past human 
behavior, which can be discerned in prehistoric archaeological sites, historic-era archaeological and 
architectural resources, artifacts and objects, historical buildings and structures, traditional cultural 
properties, and Native American sacred sites. 

When a federal agency conducts a study or identifies a proposed project, the primary historic 
preservation statute that drives the cultural resource work is usually Section 106 of the National 
Historic Preservation Act (NHPA], as amended (16 USC § 470 et seq.]. The regulations 
implementing Section 106 of the Act are promulgated by the Secretary of the Interior, as codified in 


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36 CFR § 800. Section 106 requires agencies to make a good-faith effort to identify cultural 
resources in the area of potential effects, defined as the geographic area within which a project may 
directly or indirectly cause alterations in the character or use of historic properties. Identified 
resources are then evaluated for their significance and integrity by applying the criteria of the 
National Register of Historic Places (National Register), and to consult with Native American tribes, 
the State Historic Preservation Officer (SHPO), and interested parties as appropriate. This is known 
as the Identification and Evaluation phase of the Section 106 process. 

When a cultural resource is determined through consensus to be eligible for listing in the National 
Register (an "historic property" in federal terminology) and all or part of it may be damaged or 
destroyed (an "adverse effect"), the agency, SHPO and tribal representatives consult to seek ways to 
not adversely affect the historic property, possibly through redesign of project features. In 
situations where adverse effects are unavoidable, a treatment plan is developed to resolve the 
effects, and a memorandum of agreement is often executed by the agency and the SHPO, with tribes 
given an opportunity to concur in the agreement. Resolution of adverse effects to historic 
properties typically involve archival and technical research, scientific excavations to recover 
information, photo and archival documentation, and interpretive and education programs to 
preserve data that would otherwise be lost when a project is implemented. 

The NHPA authorizes the Secretary of the Interior to maintain and expand a National Register of 
districts, sites, buildings, structures, and objects of significance in American history, architecture, 
archaeology, engineering, and culture. A property may be listed in the National Register if it meets 
criteria for evaluation defined in 36 CFR § 60.4. The quality of significance in American history, 
architecture, archaeology, engineering, and culture is present in districts, sites, buildings, 
structures, and objects that possess integrity of location, design, setting, materials, workmanship, 
feeling and association and: 

(A) that are associated with events that have made a significant contribution to the broad 
patterns of our history; or 

(b) that are associated with the lives of persons significant in our past; or 

(c) that embody the distinctive characteristics of a type, period or method of construction, 
or that represent the work of a master, or that possess high artistic values, or that 
represent a significant and distinguishable entity whose components may lack 
individual distinction; or 

(d) that have yielded, or may be likely to yield, information important in prehistory or 
history (36 CFR § 60.4). 

A property must meet one or more of these specific criteria to qualify as a good representative of a 
significant historical theme or pattern. It must be associated with important historical events or 
persons (Criteria A and B); convey important technical, aesthetic, or environmental values 
(Criterion C); or have potential to provide important scientific or scholarly information 


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(Criterion D], Unless a site is of exceptional importance, it is not eligible for listing in the NRHP 
until it is 50 years of age. 

A property determined eligible must also retain enough integrity to enable it to convey its historic 
identity; in other words, to be recognizable to a historical contemporary. The NRHP recognizes 
seven aspects or qualities that, in various combinations, define integrity: Location, the place where 
the historic property was constructed or the place where the historic event occurred; Design, the 
combination of elements that create the form, plan, space, structure, and style of a property; Setting, 
the physical environment of a historic property; Materials, the physical elements that were 
combined or deposited during a particular period of time and in a particular pattern or 
configuration to form a historic property; Workmanship, the physical evidence of the crafts of a 
particular culture or people during any given period in history or prehistory; Feeling, property's 
expression of the aesthetic or historic sense of a particular period of time; and Association, the 
direct link between an important historic event or person and a historic resource. 

A historic resource maintains integrity when the property possesses several, and usually most, of 
these aspects. The significance of a resource (why, where, and when a property is important] must 
first be fully established, and only after significance is established can the integrity be addressed. 
The seven elements of integrity are most appropriately applied to standing buildings, structures, 
and objects. Location is a critical element for all resource types, but for archaeological sites the 
other six aspects are not readily applicable to most archaeological sites. A more relevant (and 
commonly applied] measure of integrity for archaeological sites is the resource's physical 
properties, i.e., the vertical and horizontal structure of the deposit. 

Delineation of Area of Potential Effects: The Area of Potential Effects (APE] consists of (1] the 
River channel and both banks, approximately 150 feet wide from the stream center line, within 
which cut-and-fill work and placement of gravel in the stream would occur, and (2] unspecified 
channel areas downstream of Reach 12 where gravel migration from Reach 12 is expected to occur. 

The USACE and SCVWD become aware of a dump site of historic-era debris, which is situated in the 
APE. This generated the archaeological research and site inspection of this area reported below. It 
was proposed that a foundation of engineered fill would be placed over the archaeological site to 
avoid impacts if necessary, since early designs would have placed an access ramp at or near this 
location. 

Identification of Cultural and Historic Resources: In November 2013, prior to the historic-era 
deposit inspection and survey of the APE for additional cultural resources, the USACE conducted 
the standard records search, including information of areas previously surveyed by cultural 
resource specialists and information on any known prehistoric archaeological or historical-era 
resources on file with the Northwest Information Center (NWIC], California Historical Resources 
Information System. The search included checking the National Register of Historic Places by 
accessing the National Park Service website f http://www.nps.gov/historv/nr /research/ ! 


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reviewing the California Inventory of Historic Resources, California Historical Landmarks, Heritage 
Resources of Santa Clara County, and the Historical Atlas of Santa Clara County. 

The USACE reviewed its cultural and historical resource information, and interviews were 
conducted with project engineers and planners. It was determined that the location of the historic- 
era site in question was situated adjacent to farm properties surveyed by archaeologists in the 
1970s. The site was not recorded with the NWIC, nor was it mentioned in any documentation. The 
field evaluation of the historic-era deposit and the archaeological survey of the Reach 12 area of 
potential effects were performed in December 2013. 

The NWIC information revealed two ranch and farm properties recorded in the vicinity of the 
historic deposit, identified as P-43-000694 and P-43-000695, recorded by professional historians 
during architectural surveys in the 1980-1990s. The farms and buildings, which were far removed 
from the river and never in the area of potential effects, no longer exist. The information from the 
record forms provides a historic context for the historic-era deposit. 

The P-43-000695 record forms documented a ranch complex known as the Malech Ranch that once 
covered about 30 acres and consisted of nine structures of wood-frame construction: a main house, 
tank house, sheds of undetermined use, a fruit-packing shed, two barns, and a garage. The complex 
of buildings was situated along the Almaden Expressway about 0.5 mile southwest of the historic 
deposit. This was a family operated farm first developed around the turn of the 20th century, 
apparently with the earliest period dominated by hay, grain, and livestock, and in later decades 
used to grow fruits and vegetables. The orchards on the property consisted of prunes, apricots, 
walnuts, and peaches; also present were a small vineyard, and acres of alfalfa. At the time that the 
property was recorded, the buildings did not "exhibit significant architectural characteristics” but 
appeared "to possess sufficient age and integrity to be listed on the National Register.” 

The P-43-000694 records documented two agricultural properties, one of which contained the 
Malech Ranch. The other associated with the architectural survey was the Cassibba house and 
farm: a Craftsman-style house, representative of a vernacular residence from the early 20th 
century, built circa 1921 and moved to the property in 1952. Ancillary buildings included a circa 
1952 wood-clad garage, an open-shed building, and a wood shed enclosing a water pump and farm 
equipment. The buildings were evaluated for historical significance, and it was noted that the 
buildings as they existed in 2008 do not "provide a direct association with events that have made a 
significant contribution to the broad pattern of the area's local history." Although the Malech and 
Cassibba families were members of the local agricultural community, "they were not known to have 
made any significant contributions to the development of the local horticultural industry.” 

The archaeological survey covered the banks of the river in Reach 12. Besides the newly 
discovered historical deposit, no other cultural resources were identified in the area of potential 
effects. The site inspection of the historic-period deposit provided the following observations: 


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• The deposit appears to have been created through multiple dumping episodes at the edge of 
the secondary terrace of the Guadalupe River; 

• Surface materials, in a matrix of gravel and cobble soil, extended for a distance of about 164 
feet; 

• Deposit materials had sloughed down slope from the terrace edge to the floodplain terrace; 
and 

• The vertical distance from top of deposit to floodplain terrace is about 26 feet. 

In addition, it was noted that the site deposit was extremely damaged from unauthorized digging, 
by so-called bottle hunters, apparently done with hand tools and leaving exposed cut banks and 
pits. The vegetation onsite was recently burned. Concrete rubble was recently dumped near the 
edge of the deposit. It is unknown how long the collectors were impacting the deposit and its 
artifacts, although it appears to have been years. It also appeared that the deposit was partly 
concealed by vegetation, which was recently burned. No evidence of direct material deposition was 
noted on the lower, primary floodplain terrace, and no evidence of digging was noted there. 

The observed deposit constituents were: (a] metal parts and tin cans, rusted and not definitive to 
function; (b] several whole glass bottles, a couple jars, but much is fragmentary, with bottle tops 
both screw-top and cork forms; (c) fragmentary ceramics, with plates of floral print ware and 
geometric border design, and also pieces of a crock pot; [d] broken concrete sewer lines and 
general rubble; [e] construction style bricks and firebrick, the later suggesting remnants of a kiln. 

National Register Evaluation: A Historic Properties Memorandum (HPM] was prepared that 
describes the APE, and presents the findings of the archaeological research, inspection of the 
historic deposit, and survey results. The HPM includes an evaluation of the resource for its 
eligibility to be listed in the National Register, which was done by applying the criterion d 
requirements (see above]. It was determined that the historic-era site does not meet criterion d 
because the data shows there is no potential to yield information important to the local history. 

The extremely disturbed condition of the deposit was clearly demonstrated. The resource, 
therefore, is not considered to be a historic property for purposes of consultation under the Section 
106. 

State Historic Preservation Officer Consultation: In January 2013, the USACE initiated Section 
106 consultation with the SHPO, requesting comment on Historic Properties Memorandum and the 
findings. The USACE believes it has completed an appropriate level of study for the proposed 
project, and that this work constitutes a "good-faith" effort to identify historic properties [36 CFR § 
800.4(a] and § 800.4(b](l]J. The USACE has made a finding of "no historic properties present” [36 
CFR § 800.4(d](l]J. The SHPO contacted the USACE within the standard timeframe, requesting 
clarification of the relationship of the currently proposed mitigation features with the originally 
authorized project. No additional comment was received from the SHPO, thus the USACE has 
satisfied its responsibilities under Section 106 of the NHPA. 


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Significance Criteria: An impact would be considered significant if it has the potential to adversely 
affect a historic or cultural resource that is currently listed on the National Register or determined 
by consensus to be eligible for listing. 

3.7.1 Potential Impacts and Mitigation Measures 

Impact HIST-1: Adversely affect a resource that is listed or determined eligible for listing on the 
National Register. The USACE expects the SHPO to concur with the HPM findings and conclusion, 
i.e., no National Register cultural or historic resources in the APE, and therefore, such resources 
would not be adversely affected. No mitigation is required. 

3.8 Noise 

Airborne sound is a rapid fluctuation of air pressure and local air velocity. Sound levels are 
measured and expressed in decibels (dB] with 0 dB roughly equal to the threshold of human 
hearing. The frequency of sound is a measure of the pressure fluctuations per second, measured in 
Hertz (Hz]. Most sounds do not consist of a single frequency, but are comprised of a broad band of 
frequencies differing in level. The characterization of sound level magnitude with respect to 
frequency is the sound spectrum. 

Many rating methods exist to analyze sound of different sound spectra. Generally, the simplest 
method is used so that measurements may be made and noise impacts readily assessed using basic 
acoustical instrumentation. The method uses a single weighting filter which progressively de- 
emphasizes frequency components above 5,000 Hz and below 10,000 Hz. This frequency, called A- 
weighting is measured in A-weighted decibels (dBA] and reflects the relative decreased sensitivity 
of humans to both low and extremely high frequencies. 

Noise levels diminish (or attenuate] as distance from the source increases based upon an inverse 
square rule, but the rate of attenuation varies with the type of sound source. Sound attenuates from 
point sources, such as an industrial facility, at a rate of 6 dB per doubling of distance. Roads 
typically have an attenuation rate of 4.5 dB per doubling of distance. However, heavily traveled 
roads with few gaps in traffic are typically characterized as a line source with an attenuation rate of 
3 dB per doubling of distance. 

The duration of noise and the time period at which it occurs are important factors in determining 
the impact of noise on sensitive receptors. A single number, called the equivalent continuous noise 
level (L eq ) is used to describe a noise level over a period of time. The L eq is a calculated single level 
for a specified duration, which contains the same energy as all of the varying sounds over the 
measurement period. While not identical to an average, especially when noise fluctuations are 
great, the L eq is widely used to represent an average noise level over some period of time. Other 
common measurements include the minimum and maximum sound levels (L m j n and L max ],and 
percentile-exceeded sound levels such as Lio, L20, which is the A-weighted sound level that is 
exceeded 10 percent of the measurement period, 20 percent, etc. L50 is the level exceeded 


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50 percent of the period, and so on. L 50 is the median sound level measured during the 
measurement period. 

In determining the daily measure of community noise, it is important to account for the difference 
in human response to daytime and nighttime noise. Noise is more disturbing at night than during 
the day, and noise indices have been developed to account for the varying duration of noise events 
over time as well as community response to them. The Community Noise Equivalent Level (CNEL] 
and the Day Night Average Level (Ldn] are such indices. The Ldn represents the 24-hour A-weighted 
equivalent sound level with a 10 dB weighting added to the nighttime hourly noise levels (HNL] 
between 10:00 p.m. to 7:00 a.m. The CNEL is computed identically to the Ldn but with the addition 
of a 5 dB penalty to the evening HNL (i.e., 7:00 p.m. to 10:00 p.m.]. The CNEL value is typically less 
than 1 dB above the Ldn value. 

In 1974, in response to the requirements of the federal Noise Control Act, the United States 
Environmental Protection Agency (USEPA] identified indoor and outdoor noise limits to protect 
public health and welfare (communication disruption, sleep disturbance, and hearing damage]. 
Outdoor Ldn limits of 55 dB and indoor Ldn levels of 45 dB are identified as desirable to protect 
against speech interference and sleep disturbance for residential, educational, and healthcare areas. 
Sound-level criteria to protect against hearing damage in commercial and industrial areas are 
identified as 24-hour L eq values of 70 dB (both outdoors and indoors]. 

The State of California does not promulgate standards for environmental noise but requires each 
city and county to include a noise element in its general plan (California Government Code Section 
65302 (f)]. In addition, Title 4 C.C.R. has guidelines for evaluating the compatibility of various land 
uses as a function of community noise exposure. There are no other state regulations or policies 
related to noise that would apply to the project. 

The City of San Jose in its General Plan and Municipal Code has certain specific policies and 
guidelines related to noise, which are described in the Avoidance, Minimization and Mitigation 
Measures section. 

Ambient Noise in the Project Area: The proposed project is located in the City of San Jose's 
Cambrian/Pioneer Planning Area, located in southwest San Jose. Highway 85 is a major source of 
traffic noise that affects the Planning Area. Major roadways, including Almaden Expressway, 

Capitol Expressway, Coleman Road, Blossom Hill Road, Branham Lane, Hillsdale Avenue, South 
Bascom Avenue, Union Avenue, Leigh Avenue, Meridian Avenue, Cherry Avenue, Camden Avenue, 
Kooser Road, and Pearl Avenue are the biggest noise sources at land uses immediately adjacent to 
these roadways. The Cambrian/Pioneer Planning Area is mainly developed with residential land 
uses. The planning area is also developed with commercial land uses primarily found at the 
intersections of major streets (Bascom/Camden, Union/Camden, Almaden/Blossom Hill, etc.]. 


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The existing noise environment of communities along Reach 12 is mostly affected by noise sources 
that are transportation related (Highway 85, Almaden Expressway, Branham Lane and Blossom Hill 
road]. 

There are single family homes and multi-unit townhomes within 50-100 feet of the project in the 
northern portion of Reach 12 on the east side. South of Highway 85 and located adjacent to the east 
side of the project is a senior living community and the Blossom Hills Apartment Complex. Adjacent 
to the west bank of Reach 12 are percolation ponds and commercial complexes. The closest 
residences on the west bank are apartments located on Sanchez Road 500 feet away from the 
project, separated by percolation ponds. 

Percolation ponds, commercial centers and the Almaden Ranch Center comprise the rest of the land 
uses adjacent to the project. Highway 85 in an east-west direction over Reach 12 near the middle 
section of the project and is also flanked by Almaden Expressway to the west, which runs in a 
north-south direction. Other noise-sensitive land uses in those communities along Reach 12 would 
also experience noise impacts but to a lesser degree, which are mostly adjacent to the west bank of 
Reach 12. These are commercial complexes and the 45-acre Almaden Ranch Retail Center, which is 
currently under construction. 

Existing noise levels along Almaden Expressway were measured at Ldn levels of 70 dBA. Highway 
85 generates existing Ldn levels from 77 to 78 dBA at 75 feet. Vehicle traffic on Blossom Hill Road 
generates a day-night average noise level value of 71 dBA DNL at 75 feet. At 5733 Tucson Drive, 

100 feet from the center of Almaden Expressway, 70 dBA was recorded and this is about 90 feet 
from Almaden Expressway in a residential neighborhood near the proposed project site. 

Sensitive Receptors: Some land uses are generally regarded as being more sensitive to noise and 
vibration than others due to the types of population groups or activities involved. Sensitive 
population groups generally include children and the elderly. Noise sensitive land uses typically 
include all residential uses (single and multifamily, mobile homes, dormitories, and similar uses], 
hospitals, nursing homes, schools, and parks. Sensitive land uses are present along all reaches of 
the Upper Guadalupe River Flood Risk Management Project. In the Reach 12 area, the densest 
residential areas on the east side of the river. These areas include the homes along Hampton Falls 
Place, Tonino Drive, the end of Dawnview Court, the Atrium Senior Living Community, and the 
Blossom Hills Apartment Complex. 

Significance Criteria: The project would have a significant noise impact if it would expose 
sensitive receptors to nuisance noise (i.e., nuisance noise within 500 feet of residential uses or 200 
feet of commercial or office uses]. 

The federal, state, and local governments have established noise guidelines and regulations for the 
purpose of protecting citizens from potential hearing damage and various other adverse 
physiological, psychological, and social effects associated with noise. The City of San Jose has 


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adopted a Noise Element of the General Plan (Master Plan) which contains land use and noise 
compatibility guidelines consistent with state and federal guidelines. The municipal code in the 
City of San Jose does not contain a noise control ordinance which is used by some cities to control 
specific, non-transportation type noise sources such as construction noise, an essential activity 
within any city. The following is stated as a policy within the City's Noise Element concerning 
construction noise: "Construction operations should use available noise suppression devices and 
techniques." 

The Municipal Code does not establish quantitative noise limits for demolition or construction 
activities occurring in the City. San Jose considers significant construction impacts to occur if a 
project is located within 500 feet of residential uses or 200 feet of commercial or office uses. 

The extent to which a community becomes annoyed with a noise activity will be influenced by the 
background noise level of the community without the offensive noise. The higher the background 
noise, the less noticeable becomes the offensive noise. Similarly, the lower the background noise, 
the more objectionable the intruding noise is judged by the community. Another important factor, 
according to the USEPA, is the initial attitude of the community toward the operation producing the 
noise. If the community is aware that the operation causing the noise is very necessary and will not 
continue indefinitely, the impact will be less objectionable to the community. The net effect of 
background noise and community attitude, according to the USEPA, would make construction noise 
seem 5 to 15 dBA less than other noise impacts where these factors are not involved. 

3.8.1 Potential Impacts and Mitigation Measures 

Impact NOISE-1: Expose sensitive receptors to nuisance noise (i.e., nuisance noise within 500feet of 
residential uses or 200feet of commercial or office uses). Heavy equipment would be used to 
construct the site, including dozers, excavators, soil stabilizers, flat bed trucks, dump trucks, 
chippers, rollers, water trucks, and other typical construction equipment. Typical noise levels for 
common construction equipment are provided in Table 34. 

During site preparation and construction would temporarily generate sound levels ranging from 
about 70-90 dBa at 50-foot distances from heavy construction equipment. This equipment is a 
source point for sound that diminishes at about a rate of 6 dBA (depending on the source and 
terrain, the typical range for attenuation is 3-7.5 dBA for every doubling of distance from the point 
source) for each doubling of the distance from the source. For example, a 70 to 80 dBA noise range 
at 50 feet would diminish to 64 to 74 dBA at 100 feet and 58 to 68 dBA at 200 feet. Typically noise 
50 feet from highway traffic noise is about 70 dBA (100 feet away would be 66 dBA and 200 feet 
away would be 62 dBA). It is expected the construction noise levels associated with the proposed 
project will be between 74 and 88 dBA (equivalent continuous noise level). 

Reasonable noise reduction measures would be incorporated into the construction plan and 
implemented during all phases of construction activity to minimize the exposure of neighboring 


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properties in combination with the limitations on hours set forth in the City's Municipal Code would 
reduce the impact to a less-than a significant level. 


Table 34 Typical Noise Levels for 

Common Construction Equipment 
(at 50 feet) 

Equipment Type 

Lmax (dBA) 

Air Compressor 

78 

Backhoe 

78 

Cement Mixer Truck 

79 

Cement Pump Truck 

81 

Chain Saw 

84 

Compactor 

83 

Crane 

81 

Concrete Saw 

90 

Dozer 

82 

Excavator 

81 

Dump Truck 

76 

Flat Bed Truck 

74 

Front End Loader 

79 

Fork Lift 

75 

Generator 

81 

Grader 

85 

Paver 

77 

Pick-up Truck 

40 

Roller 

80 

Tractor 

40 

Tree Chipper 

87 

Source: Federal Highway Administration 2006 


Avoidance, Minimization and Mitigation Measures 

Avoidance and Minimization Measure NOISE-1: Limit construction hours. According to San Jose 
Municipal Code, construction hours within 500 feet of a residential unit are limited to the hours of 
7:00 am to 7:00 pm on Monday through Friday. No workwould be performed on Saturdays, 
Sundays, or on holidays, unless otherwise expressly allowed in writing by the USACE. While USACE 
is not subject to City ordinances, every reasonable effort will be made to comply with the City 
ordinance to reduce noise impacts. Work hours outside of hours allowed by the ordinance are only 


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expected if needed to comply with seasonal restrictions on construction activities. Furthermore, 
noise produced by construction activities would be regulated to a limit noise level of 90 dBA at a 
distance of 50 feet from the source. 

Avoidance and Minimization Measure NOISE-2: Implement best management practices. At a 
minimum, the construction operations would use the following best available noise suppression 
devices and techniques and limit construction hours near residential uses. Best management 
practices include: 

• Air compressors and internal combustion engines will be in good operating condition that 
meet or exceed original factory specifications and shall be equipped with high-grade 
mufflers, air-inlet silencers, where appropriate, and noise suppressers. 

• All mobile or fixed noise producing equipment used that is regulated for noise output by 
local, state, or federal law will comply with such regulation while in use. This will include 
vehicles licensed for use on public highways. 

• Electrically-powered equipment instead of pneumatic or internal combustion powered 
equipment will be used, where feasible. 

• The use of noise-producing signals, including horns, whistles, alarms, and bells will be for 
safety warning and emergency purposes only. 

• No music system including personal or vehicle radio, tape, or CD players or the like will be 
audible at the project right of way line. 

• Trucks or other mobile equipment will not use engine decompression ("Jake Brakes”] for 
deceleration on grades. 

• Taking all necessary precautions during its operations to limit peak particle velocities from 
vibratory compaction or percussion equipment so that they do not become a public 
nuisance or result in property damage. 

The USACE will occasionally take sound readings with a hand-held noise level meter during 
construction activities and operations of any noise-producing equipment to monitor compliance 
with the noise criteria. Any equipment causing incompliance with the noise criteria shall be 
removed from the job site as directed by the USACE. 

3.9 Recreation 

Recreational activity at the project site is primarily associated with land based recreation along the 
Guadalupe River Trail, a paved pedestrian and bicycle path that runs along the banks of the 
Guadalupe River including the east bank of Reach 12. District maintenance roads along the east 
bank of Reachl2 are not authorized for recreational use but may sometimes be informally used as 
trails by local residents. No water-based recreational activities, such as boating, fishing, or 
swimming, are sanctioned or known to take place along Reach 12 of the river. 


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The entire Guadalupe River Trail is approximately 11.4 miles long and composed of two 
discontinuous segments: a 1.4-mile segment along the Upper Guadalupe River from Chynoweth 
Avenue to Almaden Lake Park, and a longer segment along the Lower Guadalupe River from the 
intersection of Alviso and Gold Streets to Grant Street near Highway 280 (City of San Jose, 2014], 
The Highway 87 Bikeway serves as an indirect link between the two discontinuous segments of the 
trail and thus the trail is used for both recreation and commuting to downtown San Jose from 
outlying neighborhoods. The portion of the Guadalupe River Trail running along the east bank of 
Reach 12 extends from Blossom Hill Road downstream to the vicinity of State Route 85 where the 
trail diverges east to Chynoweth Avenue (Figure 24 in yellow and red]. 

Significance Criteria The proposed action would have a significant impact on recreation if it would 
result in permanent degradation or elimination of recreational opportunities in the project area. 

3.9.1 Potential Impact and Mitigation Measures 

Impact REC-1: Temporary Closure of a Portion of the Guadalupe River Recreational Trail. As part of 
the proposed action, an approximately 1,600-foot long section of the existing trail along Reach 12 
would be closed to public use for the duration of project construction (approximately 18 months). 
The trail would be closed from the northern terminus (cul-de-sac) of Blossom River Drive to the 
intersection of Blossom Hill Road/Blossom Hill Drive (24; Red Path). Closure of this section of the 
Guadalupe River Trail would be temporary and cease at the completion of construction. This, along 
with implementation of Avoidance and Minimization Measure REC-1, a detour directing users along 
an alternate path around the closed section of trail during construction, would mitigate the 
potential impact to a less-than a significant level. 

Impact REC-2: Degrade the condition of the existing, paved recreational trail. The existing paved 
trail is designed for pedestrian and bicycle traffic however, under the proposed action, trucks and 
construction equipment would utilize the trail to access the reach and haul materials. Vehicular 
usage may result in degradation or damage of the paved surface of the road. Implementation of 
Mitigation Measure REC-2, repair and repaving of the trail to existing conditions after construction, 
would mitigate this potential impact to a less-than a significant level. 

Avoidance and Minimization Measures 

Avoidance and Minimization Measure REC-1: Implement detour around the closed section of trail. 
Under the proposed action, trail users would be detoured at temporary trail closure points to an 
alternate pathway during construction. The SCVWD has a joint-use agreement with the City of San 
Jose allowing the District to close the trail for public safety and maintenance and operation of the 
flood protection project. The SCVWD would notify the City of San Jose Department of Parks, 
Recreations and Neighborhood Services (Trail Program) of the necessary closure and coordinate 
with the City to determine the most feasible detour route for trail users. One potential detour 
routes is currently being considered. The detour is described below and illustrated in Figure 24. 


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Chynoweth Avenue 


Legend 


Existing Guadalupe River Trail 

Closed During Construction 
Open During Construction 

Existing Trailhead to Remain Open 


Points of Closure to Through Traffic 


Proposed Detour Route 

Blossom River Dr/Way to Winfield Blvd Detour 

General Project Area 


Blossom Hill Road 


Figure 24. Potential Recreation Trail Detour Routes 


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Blossom River Drive to Winfield Boulevard Detour (Figure 24, Purple Path], Northbound trail 
users would pass under Blossom Hill Road using the trail underpass and then be immediately 
routed up to street level on Blossom River Drive. Users would continue north on Blossom River 
Drive to Blossom River Way where they would continue east. At Winfield Boulevard, users would 
turn north and continue to Chynoweth Avenue where they could continue on with the recreation 
trail. Southbound trail users would be detoured to Winfield Boulevard at the existing trailhead 
north of the VTA light rail crossing of Winfield Boulevard. The trail would proceed south on 
Winfield Boulevard, west on Blossom River Way, and south on Blossom River Drive. 

The detour would have clear signage with directions and a map for following the detour would be 
posted in numerous locations along the existing trail and the detour route itself. The trail closure 
signs would conform to City of San Jose requirements and would be placed at least two weeks 
ahead of the actual closure date to give advance warnings to regular trail users. 

Mitigation Measure REC-2: Repair and/or re-pave trail to existing condition after construction. At 
the completion of construction, the contractor would repair or repave the closed section of trail to 
restore it to its existing condition prior to re-opening the trail to public use. Similarly, if the Blossom 
River Drive detour is selected, at the completion of construction, the pathway portion of the detour 
running between the Blossom River Drive cul-de-sac and the existing Guadalupe River Trail would 
be restored to existing condition and the chain link-fencing along the existing Guadalupe River Trail 
would be replaced. 

3.10 Transportation and Traffic 

The proposed project is located within a developed area consisting of commercial and residential 
properties, along with construction activities not related to the project. While the proposed project 
is not expected to result in road closure or replacement, traffic on roadways in the vicinity of the 
project has the potential to be affected. Regional access in the study area is provided by Guadalupe 
Parkway, State Route [SR] 87. Important streets in the vicinity of the project are described below 
and shown on Figure 25. 

Guadalupe Parkway. Guadalupe Parkway is located north of the project area. It is a four to six lane 
expressway / arterial that extends from U.S. 101 south to SR 85. 

Almaden Expressway (G8): Almaden Expressway is a six-lane major arterial with industrial, 
commercial, and residential uses. It serves as a parallel facility to SR 87, extending from Almaden 
Road near Alma Avenue to Harry Road in south San Jose. The traffic count generated from Google 
Earth estimates that the Almaden Expressway serves over 58,000 cars per day. 

Blossom Hill Road ( G10 ): Blossom Hill Road is a four to six lane major arterial with industrial, 
commercial, and residential uses. Extending from U.S. 101 to SR 17, portions of this road serve as a 


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parallel facility to SR 85. The traffic count generated from Google Earth estimates that this road 
serves over 35,000 cars per day. 

Blossom River Drive: Blossom River Drive is a short (approximately 0.3-mile-long] two lane road 
immediately east of the project area. It begins at Blossom Hill Road and travels north to its cul de 
sac terminus past Blossom River Way at Guadalupe River Trail. It provides access to residences 
areas. 

Blossom River Way: Blossom River Way is a short (approximately 0.15-mile-long] two-lane road 
that connects Blossom River Drive to Winfield Boulevard. It provides access to multi-family 
residences north and south of the street. 

Sanchez Drive: Sanchez Drive is a short (approximately-0.35-mile long] two lane road located 
immediately west of the project area. It begins at Blossom Hill Road and ends at a parking lot 
located to its west (just before Highway 85], It provides access to residences and commercial areas. 

Guadalupe River Trail: The Guadalupe River Trail is a major bicycle and pedestrian transportation 
route. It is used daily by commuters traveling around the area. An analysis of closing portions of 
this trail during construction is provided in Section 3.9. 

Significance Criteria: The project would have a significant effect on transportation and traffic 
resources if it would: 

• Substantially interfere with surrounding traffic which would result in major delays. 

• Adversely affect roads and highways. 

• Safety 

3.10.1 Potential Impacts and Mitigation Measures 

A portion of the project entails earth moving activities including removal of grub material and 
grubbed soil, removal of excess sediment, importing of gravel, importing of clean backfill sediment, 
and importing of road aggregate. Table 35 shows the anticipated truck count for the quantity of 
material estimated and the duration of the hauling activities. As the work activities are limited to 
8:00 am to 5:00 pm during weekdays, not including holidays, the maximum average anticipated 
frequency of the truck loads is approximately every 15 minutes. 

The haul routes anticipated would be the blue paths, as shown on Figure 25. As shown, there are 
five points of entry (Figure 25, yellow double arrows] into the project area—two in the north end 
(one on each bank of the reach], one in the south end providing ingress and egress to the western 
bank of the project, and two in closer to the middle (one on each side of the bank]. Truck hauls 
would maximize use of larger roads and expressways (i.e., Almaden Expressway, Blossom Hill Road, 
and Branham Lane] to gain entry to the State Route 85 by access the project site from the north and 
south entry points. Trucks would travel along the routes show either from the project site to State 


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Route 85 or from State Route 85 to the entry points. The project would add at a maximum an 
additional 35 trucks to the flow patterns, which would not significantly alter the quantity of traffic 
on the roads proportionate to the overall flow. 


Table 35 Number of Truck Hauls Required to Transport Equipment and 

Construction Material 

Purpose of truck trip 

Truck Loads 1 

Construction Year 

Construction 

Duration 
(months) 2 

Removal of vegetation 

1,230 3 

1 (2014} 

2 

Import gravel 

668 

2 [2015] 

3 

Dispose of excess 
excavated sediment 

1,103 4 

2 [2015] 

10 

Import clean backfill 
sediment 

175 

2 [2015] 

Import road aggregate 

253 

2 [2015] 

1.5 

Total Truck Trips 

3,429 

-- 

NOTES: 

1 Assumes that heavy equipment would be transported to the site on large flatbed trucks. Import and export material would be 
transported in 10 cy trucks. 

2 Construction months are approximate, per the work schedule. Need to determine approximate number of trucks per day based on this. 

3 Approximately 12,300 cubic yards of vegetation would be cleared or removed by hand and require disposal in 2014. This would 
require approximately 1,230 haul trips. 

4 Approximately 4,100 cubic yards of soil would require removal following clearing and grubbing. Additionally, 6,030 cubic yards of 
excavated sediment would require removal. This would result in a total of approximately 1,103 haul trips in 2015. 


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Legend 

Project boundary 

Haul routes 

Ingress / egress 
(project site) 

Ingress / egress 
(freeway) 


N 

(Not to scale) 


Figure 25. Major Roads and Construction Haul Routes 


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Impact TT-1: Substantially interfere with surrounding traffic which would result in major delays. 
Although not anticipated, potential impacts may also include lane closures, removing and replacing 
traffic control systems, fencing, railing, barricades, crash cushions, channelizers, pavement, 
driveways, curbs, gutters and sidewalk and pavement markings, adjacent to or near the project 
area. Temporary construction signs would be installed in the area to direct traffic as necessary 
which has the potential to impact sprinkler systems or landscaping. Resulting debris or residual 
materials may occur on roadways or sidewalks as a result of moving earthen materials such as soil, 
sand or gravel. 

Additional impacts include an influx of cars to the area as a result of the workers personal vehicles 
that would require parking. Given the residential nature of the surrounding area, parking areas 
may be limited and an influx of cars without proper controls could result in impacts to available 
parking to residents and restricted movement in the community. 

While construction traffic is expected to cause minor delays in the truck haul areas, these delays 
would be temporary and short-lived. Further, implementation of Avoidance and Minimization 
Measures TT-1, TT-2 and TT-3 would ensure that impacts to transportation and traffic would be less 
than significant. 

Impact TT-2: Damage roads and highways. Although not anticipated, the potential for road 
damage, such as potholes, exists as a result of the increase in heavy equipment and trucks or 
through non-routine hauling actions that may arise. Implementation of Mitigation Measure TT-4: 
Repair any damage to roadways resulting from construction-related traffic would ensure that this 
impact is less than significant. 

Impact TT-3: Result in injury or harm to other drivers, pedestrians, bikers, or others using any form 
of transportation in the project area. 

All of the potential impacts listed above would be slight and temporary in nature. There are no 
long-term significant impacts to traffic associated with the preferred project. 

Avoidance, Minimization, and Mitigation Measures 

Additional traffic and trucks to the area are not an avoidable occurrence; therefore minimization 
measures were established and potential mitigation measures were identified. The project will 
actively seek to avoid or minimize unnecessary disturbance of the neighborhood from construction 
activities. Actions to ensure impacts to transportation and traffic are minimized are listed below. 

Avoidance and Minimization Measure TT-1: Prepare and implement a traffic control plan. Prior to 
the start of work a traffic control plan would be developed which would abide by the City of San 
Jose and State specifications. The traffic control plan would be submitted to the City of San Jose 
prior to the preconstruction meeting. The coordination with the city would include obtaining a 


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"Haul Route Permit" from the City of San Jose to transport construction materials to the site and to 
transport surplus materials over the City of San Jose streets. 

Avoidance and Minimization Measure TT-2: Utilize traffic control safety measures. Traffic control 
would be performed to maintain safe vehicular, pedestrian, and cyclist traffic during construction 
and to perform best management practices. These practices include mitigating high peak and high 
volume construction traffic, prevent idling and queuing, establish site access limitations and 
mitigation measures, identify haul routes, and provide overall control of all construction traffic 
entering and exiting and operating within the project site. During delivery and export of 
construction materials and equipment, traffic flaggers and signs along the access route would be 
present. Operations and schedule cleanups shall be performed to cause the least possible 
obstruction and inconvenience to traffic, pedestrians, cyclists, adjacent property owners. 
Inspections of traffic control zones shall be performed on a daily basis. 

Any traffic control system that is removed during the construction would be immediately replaced 
with a permanent approved structure or a temporary structure. At the time which construction is 
complete the traffic control structures would be returned to the original state or completed in the 
approved plan. All construction signs shall be placed in the field and shall be visible to drivers and 
not covered or blocked by trees or other fixed objects. Prior to installation of any construction 
signs in planting strips, sprinkler system conflicts would be verified. If landscaping is found to be 
damaged upon removal of construction area signs, it would be replaced to original condition. Any 
potholes or other such damage following the use of the roads would be remedied as necessary to 
previous condition. Stockpiling of materials or parking of equipment would not be allowed on 
streets and sidewalks and all streets and sidewalk areas shall be swept clean. 

Avoidance and Minimization Measure TT-3: Minimize interference with existing traffic. The 
working area would be clear of parked vehicles to maintain sight visibility and access to adjacent 
properties. Existing road signs shall not be blocked at any time. Personal vehicles of the 
employees, and equipment and vehicles shall not be parked on the traveled way, shoulders, 
medians or lanes which have not been approved for closure. When entering or leaving roadways 
carrying public traffic, the equipment, whether empty or loaded, shall in all cases yield to public 
traffic and shall travel in the direction of the traffic. No driveways or private roads shall be blocked. 
Safe access must be maintained for pedestrian traffic throughout the work areas at all times. 

Trucks and personnel vehicles parking and access shall be in compliance with local permits and 
ordinances. All construction equipment and worker vehicles arriving at the site shall park within 
the site. The workers or other associates shall not park in residential areas where the preferential 
parking in those residential areas belongs to the residences themselves. Ultimately, parking shall 
be first come, first served, but residential owners have priority over parking in their residential 
communities. The workers or other associates shall arrive onto the site no more than 30 minutes 
prior to the start of work nor remain on the site 30 minutes after the end of work. 


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Mitigation Measure TT-4: Repair and rehabilitate roads damaged by construction vehicles. Prior to 
construction, haul routes would be inspected for damage; any damage would be recorded. After 
each construction season, the routes would be inspected for construction-related damage. Any 
damage to roadways would be repaired or rehabilitated. 

3.11 Land Use Classification 

The land in the vicinity of Reach 12 is used for a mix of commercial, residential, municipal, and 
recreational purposes. The land bordering the northwestern edge of the reach is zoned for 
commercial use by the city of San Jose. The central two-thirds of the western side of the reach are 
zoned for agriculture but are designated General Commercial in the City of San Jose General Plan for 
that area south of Chynoweth Avenue, and Very High Density Residential (25-40 DU/AC] for the 
area north of Chynoweth Avenue. Agricultural use of the area, which extends from the River to the 
Almaden Expressway, was terminated in December 1996. 

The northernmost portion of the reach is bounded to the west by retail stores and restaurants, to 
the north by Branham Lane, and to the east by property owned by San Jose Water Company (SJWC) 
and single-family residences along Tonino Drive. The SCVWD maintains a service road along the 
river. The river right-of-way (ROW] managed by the SCVWD along both sides of the northern 
segment varies from 100 to 350 feet. The SJWC operates groundwater wells, a pump house, and a 
water storage tank on its property. The residences along Tonino Drive backup to the SCVWD's 
ROW and, in some cases, residents of these properties have built structures and/or placed items 
that are suspected of encroaching on the SCVWD's ROW. Since February 2014, the SCVWD has 
made contact with residents along Tonino Drive regarding the suspected encroachment issues 
through written notices and in-person meetings. The SCVWD performed a back fence survey in 
May 2014 to confirm the property lines of the residences and has communicated with the residents 
that they will have until the end of July 2014 to relocate/remove items on SCVWD property that 
they would like to save. Any remaining items on SCVWD property would be removed if necessary 
as part of the proposed action. 

The central portion of the reach (north of the Highway 85 overpass) is bounded on the west by a 
shopping center under construction and to the east by a percolation pond used by the SCVWD for 
groundwater recharge. South of the Highway 85 overpass, the SCVWD ROW is bounded on the west 
by additional percolation ponds and a restaurant at the northwest corner of the intersection of 
Blossom Hill Road and Sanchez Drive. The two ponds on the western bank occupy an extensive 
area approximately 2,000 feet long and up to 350 feet wide. South of the highway overpass and 
east of the river, the ROW is bounded by Blossom River Drive, which parallels the river from 
Blossom Hill Road to 900 feet north of the road. Along the west side, Sanchez Drive runs north- 
south about 300 to 500 feet west of the river. The overall SCVWD's ROW in this segment of the 
reach varies from 250 to 1,000 feet in width. On the east side of the river, adjacent the percolation 
pond is a new residential subdivision. Multi-family residential uses are also present east of 
Blossom River Drive and a number of townhouses and condominiums were recently completed or 


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are under construction west of Sanchez Drive. The Blossom Hill Road Bridge forms the southern 
boundary of the reach. 

Lands Required for the Proposed Action 

Table 36 identifies the lands that would be required for the proposed action, which of those lands 
are currently owned by the SCVWD, and what easements would be required for the project. 

Approximately 29.5 acres of real estate are required for the proposed action and has been acquired 
by the SCVWD. A number of different types of easements are required for the project including 
Flood Levee Protection Easements [FLPE], Channel Improvement Easements (CIE], Permanent 
Road Easements (PRE] and Borrow Easements. The SCVWD has secured all easements. The 
Branham Lane easement was originally required for underpass work that has since been deferred 
and thus this easement is not necessary for the Reach 12 project. 

Significance Criteria: A significant adverse land use impact would result from the proposed action 
if it would conflict with the General Plan land use designation where the project is located, result in 
the conversion of public open space into urban- or suburban space, disrupt or divide the physical 
arrangement of the established community, or juxtapose incompatible land use types. 


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Table 36 Real Estate Require for the Proposed Reach 12 Project 

APN 

Physical Address 

Parcel Owner 

Parcel 

Area 

FPLE 

CIE 

PRE 

Borrow 

Sum 

458-17-009 

Roberts Lane 

San Jose, California 95118 

SCVWD 

2.78 

0.064 

1.937 

0.643 

- 

2.644 

458-18-005 

1088 Branham Lane 

San Jose, California 95136 

TCOB Enterprises 

0.18 

- 

0.018 

0.038 

- 

0.056 

458-18-012 

San Jose, California 95118 

San Jose Water 

Works 

1.15 

- 

0.218 

0.213 

- 

0.431 

458-18-080 

4606 Almaden Expressway 

San Jose, California 95118 

Uccelli Jr., George 

3.52 

0.011 

0.066 

0.194 

- 

0.271 

458-18-081 

Branham Lane 

San Jose, California 95118 

SCVWD 

2.98 

- 

2.740 

0.192 

- 

2.932 

459-16-030 

Branham Lane 

San Jose, California 95118 

SCVWD 

0.10 

- 

- 

0.003 

- 

0.003 

458-17-002 

San Jose, California 95118 

SCVWD 

2.36 

- 

2.239 

0.068 

- 

2.307 

458-17-003 

San Jose, California 95118 

SCVWD 

1.42 

- 

0.998 

0.157 

0.160 

1.315 

458-17-004 

San Jose, California 95118 

SCVWD 

2.22 

- 

1.336 

0.315 

- 

1.651 

458-17-005 

San Jose, California 95118 

SCVWD 

0.73 

- 

0.734 


- 

0.734 

458-17-018 

14540 Almaden Expressway 

San Jose, California 95118 

Almaden Ranch, LLC 

24.20 

0.020 

0.006 

0.302 

- 

0.328 

458-17-020 

14520 Almaden Expressway 

San Jose, California 95118 

Reinhard, Eli 

10.08 

0.023 

0.041 

0.230 

- 

0.294 

458-14-032 

Blossom River Drive 

San Jose, California 95123 

SCVWD 

16.32 

- 

3.265 

0.668 

0.038 

3.971 

458-16-035 

Sanchez Drive 

San Jose, California 95123 

SCVWD 

3.72 

- 

0.860 

0.201 

2.175 

3.236 


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Table 36 Real Estate Require for the Proposed Reach 12 Project 

APN 

Physical Address 

Parcel Owner 

Parcel 

Area 

FPLE 

CIE 

PRE 

Borrow 

Sum 

HWY85 

San Jose, California 95123 

State of California 

N/A 

- 

0.961 

0.191 

- 

1.152 

458-14-034 

San Jose, California 95123 

SCVWD 

23.05 

- 

5.470 

0.770 

- 

6.240 

458-14-029 

Blossom River Drive, 

San Jose, California 95123 

SCVWD 

2.84 

- 

1.506 

0.405 

- 

1.911 

Total Acres 

97.65 

0.12 

22.40 

4.59 

2.37 

29.476 


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3.11.1 Potential Impacts and Mitigation Measures 


Impact LU-1: Conflict with the Adopted General Plan Designations, Land Uses, or Physical 
Arrangement of the Community. The proposed project conforms to General Plan designations, 
would not convert public open space to urban or suburban space, and would not divide the 
community or juxtapose incompatible land uses. Thus, impacts to land use are expected to be less 
than significant. No mitigation is proposed. 

3.12 Aesthetics 

The visual resources in Reach 12 are generally quite different from other reaches due to the large 
amount of open space along most of the length of the reach, including the large percolation ponds 
on both sides of the channel north and south of the SR 85 overcrossing. In addition, even with the 
development adjacent to the river corridor, it is generally set back farther than what is usual in 
other reaches of Guadalupe River. These conditions create a more open, spacious visual setting in 
most parts of the reach for people visiting or looking upon the reach, compared to other reaches. 

Reach 12 has more public access than most reaches due to the recreation trail along the upper part 
of the reach, which extends as far north as Chynoweth Avenue via the east side of the percolation 
ponds. Most of the reach is visible from this trail, either close up or at a distance. The far upstream 
end of the reach can be viewed from Blossom River Drive and Blossom Hill Road. Distant views of 
the reach are available from portions of State Route 85, associated ramps, and Almaden 
Expressway. However, views of the reach are not available from the State Route 85 overcrossing 
due to sound walls. 

Portions of the reach can also be viewed from private residences and businesses along Sanchez 
Drive, Blossom River Drive, Almaden Expressway, and several streets northeast of the reach. For 
some of these residences, views of the river corridor may be an important part of the visual quality 
of the property. 

A private development now under construction adjacent to the west bank along the middle third of 
the reach will remove some of this open space and change the visual character of the reach. 
However, the percolation ponds will remain as publically owned open space and will help retain the 
relatively open appearance of most of the reach. 

Significance Criteria: The proposed project would have a significant impact on aesthetics if it 
would: 

• Significantly alter the viewshed by extensively removing vegetative cover. 

• Result in the viewshed being composed of construction equipment and/or activities for an 
extended period of time. 

• Result in a completed project which would have a permanent negative viewshed. 


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3.12.1 Potential Impacts and Mitigation Measures 


Impact VR-1: Losses of vegetative cover in limited portions of the river channel and the west bank 
due to construction activity and selective removal of non-native trees and shrubs. In localized areas of 
the reach, construction activities would cause temporary losses of vegetative cover due to clearing, 
grubbing, and grading activities. All disturbed locations would at a minimum be revegetated with 
hydroseeded grass, and many would be revegetated with plants visually similar to pre-disturbance 
vegetation. In cases where woody vegetation is not replaced in the same location, mitigation 
plantings would generally be placed in nearby locations. Total cover of trees, shrubs, and grasses 
would increase over current conditions, resulting in a long-term net positive effect. Temporary 
negative visual impacts in these areas would not be significant due to the small proportion of 
existing vegetation which would be affected and its scattered locations. See Table 23 for acres of 
vegetation removal and replacement. While vegetation would be removed, implementation of 
Avoidance and Minimization Measure VIS-1: Retain native vegetation to the maximum extent 
practicable and Mitigation Measure BIO-2: Replant vegetation according to the planting designs for 
the project would avoid, minimize, and mitigate for loss of vegetation cover. As such, this impact is 
expected to be less than significant. 

Impact VR-2: Temporary views of construction activities and materials. Construction activities 
would involve various types of heavy equipment, light vehicles, a construction trailer, and 
construction materials which would operate on and/or be stored on the site sporadically over a 
period of up to 18 months. The presence of these vehicles, equipment, and materials would have an 
intermittent effect on the visual quality of the site. This effect would be very minor for views of the 
site from a distance, such as from SR-87. Visual impacts from adjacent streets and residences with 
a clear view of the construction areas would be somewhat larger but still insignificant due to the 
sporadic and temporary nature of the impacts. As such, this impact is considered less than 
significant. 

Impact VR-3: New berms along the percolation ponds. The percolation ponds have wide earthen 
berms between the ponds and the adjacent river channel. About 1500 feet of berm on each side of 
the river would be raised about three feet to better keep flood flows and associated pollution and 
sediment out of the percolation ponds. The new side slopes would be hydroseeded with grass. 
These new berms would not create a significant visual impact due to their vegetated sides and their 
low height relative to the existing berms and riparian forest. The new berms are not expected to 
result in permanent adverse affects to the viewshed. Further, implementation of Avoidance and 
Minimization Measure VIS-1: Retain native vegetation to the maximum extent practicable and 
Mitigation Measure VIS-3: Hydroseed areas where vegetation would be removed would ensure that 
the completed project would not result in a permanent negative viewshed. As such, this impact is 
considered less than significant. 

Impact VR-4: Loss of trees behind houses on the east bank, downstream portion of the reach. On the 
east bank of the river between the north end of the largest percolation pond and Branham Lane, a 


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number of non-native trees, shrubs, and other plants have been planted on SCVWD land over the 
years without authorization, mostly between the existing maintenance road and the fence line. 

Some of these species are invasive and some present hazards to maintenance employees. 

The SCVWD has been working with adjacent homeowners regarding removal of unauthorized 
improvements by adjacent property owners. Some of the unauthorized trees and other plants in 
this area would be removed by USACE due to their invasive nature, as part of the proposed action. 
Avoidance measure VIS-2 would reduce these impacts, and Mitigation Measure BIO-2: Replant 
vegetation according to the planting designs for the project would mitigate all these impacts over 
time. 

It should be noted that some of the land in this area is owned by the San Jose Water Company 
(SJWC]. Trees and other plants located on SJWC land would not be removed unless this is 
determined necessary for construction access and only upon approval by the SJWC. Removal of 
trees or other plants on these lands is not expected as the maintenance road in this area is already 
maintained for access by SCVWD and SJWC maintenance vehicles. Based on this assessment, loss of 
trees behind houses is expected to result in a less than significant impact on aesthetics. 

Avoidance, Minimization, and Mitigation Measures 

Avoidance and Minimization Measure VIS-1: Retain native vegetation to the maximum extent 
practicable. Several individual trees and clumps of trees and shrubs would be retained due to their 
visual importance. Existing native trees and shrubs, including large oak trees, would not be 
removed in the area between the maintenance road and the houses. 

Avoidance and Minimization Measure VIS-2: Retain non-invasive non-native trees in this area to 
the extent practicable. 

Mitigation Measure VIS-3: Hydroseed areas where vegetation would be removed. Areas where 
plants are removed would be hydroseeded afterwards for stabilization. This would also reduce 
visual impacts by covering areas of bare earth with grass. 

3.13 Public Facilities, Utilities, and Services 

Police service for the project area is provided by the San Jose Police Department and fire service is 
provided by the San Jose Fire Department. Parks and open spaces adjacent to the project area 
include a section of the larger Guadalupe River Trail running along the east bank of the project. 
Potential effects of the proposed action on the Guadalupe River Trail are discussed in the recreation 
section]. 

Various existing utilities, including water, sewer and storm drain mains, telephone and television 
cables, and gas and electricity lines, are located above and below ground along the project route. 


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Water mains serve residences and commercial establishments and are operated by the San Jose 
Water Company and the City of San Jose Municipal Water System. Sanitary sewer and storm drain 
lines are both operated by the City of San Jose. Telephone cables are maintained and operated by 
Pacific Bell and AT&T. Gas and electricity lines are maintained and operated by the Pacific Gas and 
Electric (PG&EJ Company. 

Under the proposed action, the construction contractor would arrange with the local electrical and 
telephone utilities for temporary services deemed necessary at the project site and would provide 
and maintain field-type sanitary facilities on-site. The construction contractor would conserve any 
utilities being used to the extent practical. Temporary demand for these services on site is not 
anticipated to significantly affect regional utility service demand and would cease after project 
construction. No mitigation measures related to the provision of temporary utility service are 
recommended. 

Significance Criteria: The project would have a significant effect on public facilities, services, and 
utilities if it interferes with emergency response, damages existing utility infrastructure, or 
interrupts utility services for extended periods of time. 

3.13.1 Potential Impacts and Mitigation Measures 

Impact PUS-1: Potential Interference with Police and Fire Protection Services. During construction, 
the project may cause minor traffic congestion, occasional trespassing within the construction zone, 
and incidental events that would could call for police or fire services. Any traffic congestion that 
might be caused by this project would be slight and infrequent. Increased demand for protection 
services due to activities at the project site is also expected to be very minimal, which along with 
implementation of Avoidance and Minimization Measure PUS-1: Notification of Police and Fire 
Protection Services Regarding Construction and Implementation of Site Security Patrol, would reduce 
this potential impact to a less-than a significant level. 

Impact PUS-2: Interference with Utility Service. During construction, utilities such as gas and 
power lines may require relocation during channel construction. Relocation of utilities may result 
in short-term service interruptions to surrounding areas. Additionally, damage to existing utility 
infrastructure onsite due to construction activities could cause service interruptions. Post¬ 
construction, vegetation growth that interferes with overhead or underground utilities could lead 
to damage and potential service interruption. Implementation of Mitigation Measures PUS-2: 
Identify and Coordinate Relocation or Protection of Utilities, and PUS-3: Avoid placement of trees in 
locations that could interfere with utilities, would reduce this potential impact to a less-than a 
significant level 

Avoidance, Minimization, and Mitigation Measures 

Avoidance and Minimization Measure PUS-1: Notification of Police and Fire Protection Services 
Regarding Construction and Implementation of Site Security Patrol. During the construction period, 


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the SCVWD would notify the City of San Jose Police Department and Fire Department regarding 
construction activities that would be likely to impede delivery of police services. Contact would also 
be made with the Crime Prevention Unit to ensure that the project site and residents in the vicinity 
are visible and accessible by emergency vehicles. Additionally, a security guard would be employed 
to patrol work and transit areas during work hours to ensure safety and avoid theft/vandalism. To 
the extent necessary, the security guard might also patrol equipment, facilities, and work areas 
during night/weekends. 

Mitigation Measure PUS-2: Identify and Coordinate Relocation or Protection of Utilities. All utilities 
in the project area would be identified by a private utility locating service and coordinated with the 
utility agency. Locations of all utilities would be marked and markings made during the utility 
investigation would be maintained throughout construction. 

If relocation of utilities is deemed necessary, utility excavation and encroachment permits would be 
obtained from the San Jose Public Works Department 30-days prior to the initiation of project 
construction. Relocation of utilities would be coordinated with the appropriate utility company and 
relocation would be performed by the appropriate utility unless they directed otherwise. Approved 
barricades, temporary covering of exposed areas, and temporary services or connections for 
electrical and mechanical utilities would be arranged for utility removal. Utility service functions 
would not be interrupted without authority from the utility owner. 

Existing utility poles and utilities not relocated would be protected during construction activities to 
maintain service and prevent damage. All exposed utilities would be supported firmly and 
uniformly and no utilities would be left exposed for a period exceeding 8 hours unless approved by 
the utility. Moreover, all utility pole and guy anchors would be protected and where necessary, 
additional lateral support to poles or anchors would be provided during construction activity. 
Where temporary roads cross buried utilities that might be damaged by the loads, such utilities 
would be adequately protected. Any work adjacent to utilities would be performed in accordance 
with procedures outlined by the utility company. Where it is known or anticipated that an existing 
utility would be encountered during construction, the affected utility's owner would be notified at 
least 5 working days in advance of such work. Additionally, all utility companies and Underground 
Service Alert would be notified at least 2 working days prior to starting excavation work for the 
proposed project. Any damage to utilities would be immediately reported to the appropriate utility 
company and repaired. 

Avoidance and Minimization Measure PUS-3: Avoid placement of trees in locations that could 
interfere with utilities. Tree locations associated with the proposed project would be modified as 
necessary to avoid interference with overhead or underground utilities. Only small tree or shrub 
species would be planted in overhead utility easements. 


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3.14 


Public Health and Safety 


The proposed project does not involve the production or use of materials that pose a threat to 
public health and safety 1 so health and safety concerns associated with the proposed action relate 
to potential hazards to the public on or adjacent to the project site caused by construction 
equipment operation and construction activities. 

Public Access to the Reach 12 project area is largely unauthorized except for the portion of the 
Guadalupe River Trail bordering the reach. Despite this, unsupervised entry to the river channel 
does occur and the downstream portion of the reach has been occupied by varying numbers of 
transient and homeless people in recent years due to the relatively secluded nature of this area. 
Recent enforcement actions appear to have largely removed this population from the project area 
over a period of a number of months, so the homeless population is currently minimal. 

The public does use the Guadalupe River Trail along a portion of Reach 12 for recreation and 
commuting as well as roadways and sidewalks along Blossom Hill Road, State Route 85, Branham 
Lane, Blossom River Drive, and Sanchez Drive adjacent to the project site for vehicular, bicycle, and 
pedestrian movement. Additionally, along some portions of the reach, construction activities would 
take place in close proximity to residential and commercial areas. Potential impacts and mitigation 
measures associated with recreational trail and roadway traffic are described in Sections 3.9 
(Recreation] and 3.10 (Transportation and Traffic] of this analysis, respectively. Impacts and 
mitigation measures associated with public safety in terms of police and fire protection service are 
discussed in Section 3.13 (Public Utilities, Facilities, and Services] of this analysis. 

Significance Criteria: The project would have a significant effect on public health and safety if it 
would create a potential public health or safety hazard or involve the use, production or disposal of 
materials that pose a health hazard to people or animals or plant populations in the area affected. 

3.14.1 Potential Impacts and Mitigation Measures 

Impact PHS-1: Potential Public Safety Impacts Due to Unauthorized Entry to the Construction Area 
or the Reach After Construction is Complete. Public access and unauthorized entry into project 
construction areas might result in public safety hazards including increased potential for injury by 
construction activities, vehicles, and equipment. Homeless people currently using the site 
unauthorized could also be injured by construction activities. Post-construction, unauthorized and 
unsupervised entry into Reach 12 could also present a safety risk to individuals. Implementation of 
Avoidance and Minimization Measures PHS-1: Provide Warning Signs, Install Fencing and 
Barricades, and Implement Site Security Patrol at Construction Site During Construction and PHS-2: 


1 Some Mercury- laden sediment existing at the project site will be excavated, stockpiled, and reused or disposed 
of. Mitigation measures related to this part of the proposed action are discussed in the Geology, Soils, and 
Seismicity section of the document. 


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Limit Public Access to the River Channel Post-Construction by Installing Permanent Access Control 
Measures would reduce this potential impact to a less-than a significant level. 

Impact PHS-2: Construction Hazards to Vehicles and Pedestrians. Construction would occur 
adjacent to roadways, sidewalks, and bridges utilized for vehicular and pedestrian traffic. 

Moreover, construction vehicles would travel along roadways adjacent to the project site and, in 
some cases, cross pedestrian sidewalks to enter and egress from the site. These actions could 
create distraction hazards for passing vehicles and pedestrians. Large construction vehicles on 
roadways and crossing sidewalks as well as associated detours could present traffic or pedestrian 
safety hazards. Implementation of Avoidance and Minimization Measures PHS-3: Identify Truck 
Routes and Construction Zones Prior to Project Commencement, and PHS-4: Notify Residents of 
Construction Schedule and Proposed Traffic Detours, would reduce this potential impact to a less- 
than a significant level. 

Impact PHS-3: Displacement of Homeless Persons Occupying the Reach. Construction of the 
proposed action would displace some of the homeless people currently occupying the reach 
unauthorized through direct eviction by the construction contractor as well as construction 
activities discouraging their presence. Ongoing enforcement efforts by the City are expected to 
continue to prevent establishment of large numbers of homeless inhabitants and due to the low 
numbers of homeless people currently in the reach, this effect would be less-than significant. No 
mitigation is proposed. 

Avoidance, Minimization, and Mitigation Measures 

Avoidance and Mitigation Measure PHS-1: Provide Warning Signs, Install Fencing and Barricades, 
and Implement Site Security Patrol at Construction Site. As part of the proposed action, warning 
signs would be posted around the project site and the site would be adequately fenced and 
barricaded to prevent unauthorized access during construction. A security guard would be 
employed to patrol work and transit areas during work hours to ensure safety and avoid theft and 
vandalism. To the extent necessary, the security guard might also patrol equipment, facilities, and 
work areas during night and weekends. 

Avoidance and Mitigation Measure PHS-2: Install permanent access control measures post¬ 
construction. Permanent warning signs (e.g., no entry, no swimming or diving], fencing, barricades 
and/or other access control measures would be erected in areas along the channel, where 
necessary, to restrict or prohibit public access post-construction. 

Avoidance and Mitigation Measure PHS-3: Identify Truck Routes and Construction Zones Prior to 
Project Commencement. Prior to commencing construction activities, access routes for construction 
truck traffic would be identified and posted. Construction zones would be clearly marked by posted 
signage and flag personnel used wherever necessary to direct traffic, particularly in areas where 
construction traffic would cross pedestrian walkways to enter or exit the site. 


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Avoidance and Mitigation Measure PHS-4: Notify Residents of Construction Schedule and Proposed 
Traffic Detours. Notification would be given to residents and businesses in the surrounding area 
before construction begins. Alternate traffic, pedestrian, and recreation trail routes for impacted 
areas would be posted monitored, and maintained throughout the construction period. 

3.15 Irreversible Changes and Irreversible Commitment of Resources 

The proposed project would not result in irreversible changes or irreversible commitment of 
resources with the exception of funds and energy expended on construction and maintenance. 
Proposed channel modifications, gravel nourishment, and plantings could be reversed if this were 
deemed appropriate. 


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4.0 Other Required Analysis 

4.1 Cumulative Impacts 

The Upper Guadalupe River Project is part of a larger system of projects that provide flood risk 
reduction and other benefits to the Guadalupe River watershed. Projects in watershed system 
include seven reservoirs in the upper portion of the watershed, two diversions into percolation 
ponds near Lake Almaden, and four civil works projects along the Guadalupe River: the Upper 
Guadalupe River Project, the Guadalupe River Project (also known as the Downtown Project], the 
Lower Guadalupe River Project, and the South San Francisco Bay Shoreline Study. 

The Upper Guadalupe River Project is the last of the three civil works projects that will be 
constructed along the Guadalupe River mainstem to reduce flood risk in the watershed. The project 
extends over 5.5 miles of the Guadalupe River, from Blossom Hill Road Bridge downstream to the 
Southern Pacific Railroad Bridge just south of Interstate 280. The project area also includes 
portions of Ross Creek (extending 5,200 feet upstream from its confluence with the Guadalupe 
River in Reach 11] and Canoas Creek (extending 2,800 feet upstream from its confluence with the 
Guadalupe River in Reach 10A], The total project length is divided into seven reaches (Reach 6 
through Reach 12], each of which is distinguished by a major street or railroad crossing. 
Implementation of the Upper Guadalupe River Project was initiated in Reach 10B in 2009 and in 
Reach 6 in 2011. Reach 6 is entirely non-federal but was included in the permitting and other 
environmental compliance for the project. 

The only potential cumulative impacts from other projects in the region include the construction 
efforts of the Almaden Ranch Retail Center, which is ongoing. This center will be located adjacent to 
the downstream portion of the channel on the west bank. Construction is ongoing and expected to 
be complete by February 2015, prior to the proposed project's 2015 construction start. Cumulative 
impacts to traffic could occur from additional construction vehicles entering Almaden Expressway 
in 2014, during vegetation removal. However, the timeline for the construction would not result in 
cumulative significant impacts due to staggered timing for the major construction efforts for the 
two projects. 

4.2 Interrelated and Interdependent Activities 

None are identified. 


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5.0 


Environmental Compliance 


This section discusses the federal environmental laws and regulations the project must comply 
with prior to issuing and final Finding of No Significant Impact (FONSI], The SCVWD is preparing a 
separate California Environmental Quantity Act (CEQA] which will identify any state or local 
environmental compliance requirements. CEQA and other state and local environmental 
compliance requirements are not discussed further in this document. 

National Environmental Policy Act (NEPA) of1969 (42 USC §§ 4321 etseq) 

NEPA requires that environmental consequences and project alternatives be considered before a 
decision is made to implement a federal project. NEPA established requirements for preparation of 
an Environmental Impact Statement (EIS] for projects potentially having significant environmental 
impacts, and an EA for projects with no significant environmental impacts. 

An EIS for the overall federal Upper Guadalupe River Flood Risk Management Project was finalized 
in 1999. This supplemental EA was prepared to disclose the changes to the Reach 12 project 
description, disclose impacts of the project changes, and develop mitigation measures associated 
with the proposed project, as discussed in the CEQ regulations on implementing NEPA (40 CFR §§ 
1500-1508], 

Endangered Species Act of1973 (16 USC§ 1451 etseq) 

The Federal Endangered Species Act (ESA] protects threatened and endangered species by 
prohibiting federal actions that would jeopardize continued existence of such species or result in 
destruction or adverse modification of any critical habitat of such species. 

The NMFS issued a Biological Opinion (BO] for the Upper Guadalupe River Flood Risk Management 
Project in 2000, and a supplemental BO was issued in 2005 to address a compressed project 
schedule. The BOs required that the riparian forest and SRA cover mitigation be installed per the 
description in the 1999 EIS/EIR and MMP. They further required continuous temperature 
monitoring to ensure river temperature did not increase to a degree that would adversely affect 
fish. Two reasonable and prudent measures were included in the BOs: fish relocation prior to 
dewatering and submission of annual reports to document the status of construction and 
monitoring activities. 

The proposed project is not expected to result in changes that would violate the existing BOs. The 
NMFS concurred in a letter dated July 17, 2014. 

Biological Opinion 

The NMFS issued a supplemental biological opinion (BO] and incidental take statement in 2005 for 
the greater Upper Guadalupe River Flood Risk Management Project in February 2005. In the BO, 


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NMFS concluded that the project is not likely to jeopardize the continued existence of threatened 
Central California Coast (CCC) steelhead. 

Section 9 of the Endangered Species Act (ESA] prohibits the take of endangered and threatened 
species without special exemption. Take is defined as to harass, harm, pursue, hunt, shoot, wound, 
kill, trap, capture, or collect or to attempt to engage in any such conduct Harm can arise from 
significant habitat modification or degradation where it actually kills or injures protected species 
by significantly impairing essential behavioral patterns, including breeding, spawning, rearing, 
migrating, feeding, or sheltering. Incidental take is defined as take that is incidental to, and not the 
purpose of, the carrying out of an otherwise lawful activity. Under the terms of Section 7(b](4] and 
7(o](2] of the ESA, taking that is incidental to and not intended as part of the proposed action is not 
considered to be prohibited taking under the ESA provided that such taking is in compliance with 
the provisions of the supplemental incidental take statement issued for the project by NMFS 2 . 

The supplemental incidental take statement issued by NMFS for the overall Upper Guadalupe River 
Flood Risk Management Project estimates that approximately ten fish per construction season may 
be taken as a result of actions associated with the proposed project. To minimize the impacts of 
incidental take of threatened CCC steelhead the incidental take statement includes a number of 
reasonable and prudent measures to be undertaken as part of the proposed project. These 
measures include minimizing in stream construction and changes to instream and riparian forest; 
use of a fisheries biologist for monitoring and relocating steelhead from affected areas; minimizing 
turbidity, sedimentation, and pollutant inputs into the river, preparing and submitting annual 
monitoring reports; ensuring designs enhance natural stream functions and benefit salmonid 
habitat; and ensuring fish passage improvements are properly designed and functioning. The 
USACE is responsible for in relation to each reasonable and prudent measure. These terms and 
conditions are specific actions that implement each reasonable and prudent measure and can be 
found in the supplemental BO and incidental take statement which are included as Appendix E. 

Clean Water Act of1972, (33 USC§ 1251 etseq) 

Section 404: Section 404 of the Federal Water Pollution Control Act Amendments of 1972 (Clean 
Water Act] requires the USACE to analyze its activities that involve placement of dredged or fill 
material into waters of the United States (33 USC § 1344], For water-dependent and non-water- 
dependent projects, the Guidelines prohibit discharges of dredged or fill material into waters of the 
United States if a practicable alternative to the proposed project exists that would have less adverse 
impacts on the aquatic ecosystem, including wetlands, and does not have other significant 
environmental consequences (40 CFR § 230 [a]]. 

In evaluating USACE projects under Section 404 of the CWA, USACE must clearly demonstrate that 
there are no practicable, less damaging alternatives. The purpose of this analysis is to provide 


2 The supplemental incidental take statement released with the supplemental BO in February 2005 supersedes the incidental take 
statement attached to the original April 18, 2000 BO. 


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information regarding the availability of practicable alternatives to the proposed project that are 
not analyzed in detail in the EA and to summarize the analysis regarding those alternatives that 
may be considered practicable after preliminary stages of screening. The USACE is responsible for 
making the formal determination of compliance with the 404 Guidelines. 

The USACE has prepared a 404(b](l] analysis for the proposed project and has determined that the 
project is the lease environmental damaging alternative (LEDPA], The 404(b](l] analysis is 
available in Appendix D. 

Section 401: Under the CWA, the state (as implemented by the relevant Regional Water Quality 
Control Board] must issue or waive Section 401 Water Quality Certification for the project to be 
permitted under Section 404. Water Quality Certification requires the evaluation of water quality 
considerations associated with dredging or placement of fill materials into waters of the United 
States. Though the USACE does not obtain Section 404 permits, a 404(b](l] analysis was prepared 
for this project, as required by Section 404 of the CWA. As such, the USACE must obtain a Section 
401 Water Quality Certification from the San Francisco Bay Regional Water Quality Control Board. 

The overall Upper Guadalupe River Flood Risk Management Project has an existing Waste 
Discharge Requirement (WDR] and Water Quality Certification (WQC], which includes the original 
Reach 12 design (Order No. R2-2003-0115. Although the design for this reach has changed, the 
project would still comply with the water quality objectives of the WDR. Additionally, the USACE 
has worked closely with the San Francisco Bay RWQCB to address issues not specifically mentioned 
in the WDR. The USACE will continue to work closely with the RWQCB to ensure full compliance 
with the existing WDR or any amendments made to it. 

Waste Discharge Requirements (WDR) and a Water Quality Certification (WQC) 

The California Regional Water Quality Control Board (RWQCB], San Francisco Region, issued Waste 
Discharge Requirements (WDR] and a Water Quality Certification (WQC] for the overall Upper 
Guadalupe River Flood Risk Management Project in December of 2003. The WDR and WQC include 
specific conditions and requirements that the project must comply with during implementation in 
order to ensure the protection of the quality of jurisdictional waters and prevent impacts to 
beneficial uses. The WDR and WQC are included as Appendix F of this document and the primary 
provisions are summarized below. 

Work Windows: The WDR and WQC limit any construction in the Guadalupe River that falls below 
ordinary high water (2.33 year flood recurrence interval] to the summer dry season between June 1 
and October 15 of each year to prevent impacts to steelhead trout and Chinook salmon (unless 
other approval by the Executive Regional Board Officer is received in advance]. 

Discharges: The WDR and WQC prohibit the discharge of waste (as defined by section 13050(d] of 
the California Water Code] to surface waters or surface water drainages. Prior to excavation of 


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sediment, the material to be removed would be characterized using protocols described in the 
Santa Clara Valley Water District Sediment Characterization Plan. Excavated material from the 
project that is not desirable or suitable for beneficial reuse must be placed either in an on-site 
temporary location that isolates and contains runoff, sediment, or decant water from contacting 
jurisdictional waters, or in a designated off-site temporary or permanent location or permitted 
landfill. The discharge of decant water from these temporary excavated material stockpiles or 
storage areas is prohibited unless best management practices are adopted to ensure the decant 
water complies with effluent and receiving water limitations. 

Erosion Control: The WDR and WQC require exposed surfaces to be stabilized with erosion 
control materials and/or revegetated with appropriate native vegetation or non-native sterile seed 
mix no later than October 15 of each year to prevent erosion. Additionally, any diversion of water 
must be performed in a non-erosive manner using a pipe or other best management practice to 
prevent flows from crossing active work sites. 

Effluent and Receiving Water Limitations: The WDR and WQC regulate the pH, turbidity, 
temperature, color, dissolved oxygen content, and pollutant levels in wastewater that drains to 
waters of the State as well as in the receiving waters of the State up to 100 feet downstream from 
the point of wastewater discharge or diverted flow. 

Water Quality Monitoring: As required by the WDR and WQC, receiving water limitations and 
background water quality conditions would be monitored in the morning and afternoon, each day, 
during hours of operation and monitoring results would be reported to the RWQCB every 2 weeks 
or immediately upon request by a RWQCB representative. If any receiving water limit is exceeded 
for a 4-hour period, the RWQCB would be notified of the exceedance and a corrective action plan 
implemented. If any receiving water limit is exceeded for an 8-hour period, construction activities 
upstream of the discharge would be terminated and would not resume until compliance with 
receiving water limitations is restored. If dead fish or fish exhibiting stress are observed within 
1,000 feet of any project work activity or discharge, the incident would be reported to the CDFW, 
NMFS, USFWS Service, and the RWQCB Executive Officer and a qualified biologist would be 
immediately assigned to investigate the cause of the problem and define an acceptable corrective 
action plan. If the cause is related to project activities, work activities would be ceased until an 
acceptable corrective action plan can be implemented. 

Mitigation and Monitoring Program: A mitigation and monitoring plan (MMP; USACE and 
SCVWD, November 1999] would be implemented and annual technical and mitigation success 
status reports would be submitted to the RWQCB Executive Officer. As required by the WDR and 
WQC, a revised MMP would be developed if compensatory mitigation has not developed in 
accordance with the measurable objectives and other requirements of the original MMP. 


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Fish and Wildlife Coordination Act (16 USC§ 1801 etseq) 

The Fish and Wildlife Coordination was enacted to protect fish and wildlife from federal actions 
which could result in the control or modification of a natural body of water. It authorizes the 
United States Fish and Wildlife Service (USFWS] to evaluate impacts to fish and wildlife from 
proposed water development projects, and recommend project modifications or mitigation to 
protect fish and wildlife resources. 

The USFWS conducted a habitat evaluation procedure of the entire Upper Guadalupe River Flood 
Risk Management Project and issued a detailed Coordination Act Report (CAR] in 1998. Following 
proposed changes to the project design of Reach 12, the USFWS reevaluated the reach and prepared 
a Supplemental CAR specific to this reach in 2010. The conclusion of the 2010 CAR indicates that 
construction of Reach 12 would yield net habitat value benefits for all riparian models and most 
SRA cover models. However, the CAR did not "...allow for an evaluation of the extent to which 
benefits in Reach 12 would potentially offset impacts in other reaches of the flood control project." 
The 2010 Supplemental CAR is available upon request. 

Migratory Bird Treaty Act (16 USC § 703 etseq) 

The essential provision of the Migratory Bird Treaty Act (MBTA] makes it unlawful except as 
permitted by regulations "to pursue, hunt, take, capture, kill...any migratory bird, any part, nest or 
egg,” or any product of any bird species protected by the convention. The proposed action is not 
expected to result in harm of any migratory bird, nest, or egg. 

The project area is known to provide habitat for migratory birds protected under the MBTA. To 
protect migratory birds from adverse effects of the proposed project, the USACE and SCVWD would 
conduct bird surveys of the project area and adjacent areas prior to construction as described in 
Avoidance and Minimization Measure BIOS. Areas where nesting migratory birds are identified 
would be cordoned off and protected from construction activities. Construction personnel would 
be trained on how to avoid adversely impacting migratory birds and their nests. 

National Historic Preservation Act as amended (16 USC § 470 et seq) 

The regulations implementing Section 106 of the Act are promulgated by the Secretary of the 
Interior, as codified in 36 CFR § 800. Section 106 requires agencies to make a good-faith effort to 
identify cultural resources in the area of potential effects, defined as the geographic area within 
which a project may directly or indirectly cause alterations in the character or use of historic 
properties. Identified resources are then evaluated for their significance and integrity by applying 
the criteria of the National Register of Historic Places (National Register], and to consult with 
Native American tribes, the State Historic Preservation Officer (SHPO], and interested parties as 
appropriate. This is known as the Identification and Evaluation phase of the Section 106 process. 


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In January 2013, the USACE initiated Section 106 consultation with the SHPO, requesting comment 
on HPM and the findings. The USACE believes it has completed an appropriate level of study for the 
proposed project, and that this work constitutes a "good-faith" effort to identify historic properties 
[36 CFR § 800.4(a] and § 800.4(b)(1)], The USACE has made a finding of "no historic properties 
present” [36 CFR § 800.4(d)[1]]. The SHPO contacted the USACE within the standard timeframe, 
requesting clarification of the relationship of the currently proposed mitigation features with the 
originally authorized project. 

Clean Air Act (42 USC§ 7401 etseq) 

The federal Clean Air Act (CAA) established the National Ambient Air Quality Standards (NAAQS) 
for pollutants considered harmful to public health and the environment. These criteria pollutants 
are ozone (O 3 ), carbon monoxide (CO), nitrogen dioxide (NO 2 ), particulate matter less than 10 
microns in diameter (PM10), particulate matter less than 2.5 microns in diameter (PM2.5), lead 
(Pb), and sulfur dioxide (SO 2 ). California Clean Air Act (CCAA) also established the California 
Ambient Air Quality Standards (CAAQS) for criteria pollutants. In general, CAAQS are more 
stringent than the NAAQS. 

The CAA requires states to classify air basins as either attainment or nonattainment with respect to 
quantitative thresholds in the NAAQS, and prepare State Implementation Plans (SIPs). SIPs 
articulate emission reduction strategies to maintain the NAAQS for those areas designated as 
attainment and to attain the NAAQS for those areas designated as nonattainment. 

The USACE has prepared a CAA analysis which shows that using Tier-4 construction equipment 
would ensure that the proposed project does not violate any air quality standard. The analysis is 
summarized in Section 3.6 and provided in its entirety in Appendix C. 

Executive Order 11990, Protection of Wetlands (42 Fed. Reg. 26,961, May 25,1977) 

Under this Executive Order, federal agencies are directed to provide leadership and take action to 
minimize the destruction, loss, or degradation of wetlands. The proposed action would cause 
impacts to approximately 0.001 acre of emergent wetland (approximately 40 square feet). This 
impact is expected to be passively mitigated due to scattered growth of emergent aquatic 
vegetation in shallow water habitat created by coarse sediment placement. No net losses to this 
habitat type are expected. In addition, there would be slight increases in jurisdictional wetlands 
and Other Waters of the U.S. due to creation of floodplain benches. Therefore, the proposed action 
is in full compliance with this Executive Order. 


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6.0 Circulation of the Draft EA, and Public and Agency Comments 

Circulation: The Draft Supplemental EA was circulated to the following agencies: 

•U.S. Fish and Wildlife Service 

•National Marine Fisheries Service 

•California Department of Fish and Wildlife 

•San Francisco Bay Regional Water Quality Control Board 

• Santa Clara Valley Water District 

• City of San Jose 

In addition, notice of the availability of the Draft Supplemental EA was sent to all residents in the 
vicinity of the proposed action and to local libraries, and was posted on the USACE San Francisco 
District website for viewing and downloading. Hard copies were sent to individuals who requested 
them. 

Comments and Responses: The only comments received were from the Santa Clara Valley 
Water District and the Regional Water Quality Control Board. Comments and responses are listed 
below. 

Comment 1 (RWQCBJ: The sections of the 100% design plans, specifications and environmental 
documents (NEPA EA and CEQA EIR Addendum] need to accurately reflect the SFRWQCB criteria 
for sediment re-use. 

Answer: Text and figures have been corrected to ensure consistency with RWQCB mercury 
requirements. 

Comment 2 (RWQCBJ: Given that construction will occur throughout the reach, why doesn't the 
design plans include channel modifications to ensure 100-year flow capacity? 

Answer: Construction of upstream flood control facilities prior to downstream flood control work 
would shift some flood risk downstream. This is against Corps policy, which is why the flood 
control components of projects are normally built in an upstream sequence. The issue of 
completing flood control efforts in Reach 12 will be revisited when all downstream flood control 
work has been completed. Any later flood control work in Reach 12 would be an optional future 
action and would not be required by the current proposed action or by any downstream actions 
under this project. Mitigation plantings have been located such that installation of a floodwall at a 
later date in Reach 12 would not cause loss of these plantings. 

The Proposed Action includes berms to protect the percolation ponds from floodwaters. These 
berms would not be considered flood control levees under Corps policy. The berms would not have 
a significant effect on downstream flood risk, due to the relatively small storage space currently 
available above the normal water level in these ponds that would be foregone through the 


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construction of these berms. Therefore, construction of these berms would not be inconsistent 
with deferral of a floodwall downstream in the same reach. 

Comment 3 (RWQCB], Table 23 of the EA is proposing a different mitigation ratio than is approved 
in the Order and the 1999 MMP. 

Answer: The draft table showed mitigation in relation to the Congressionally-authorized project. 
After further refinement of impacts and mitigation, and agency coordination, we have revised the 
table to update habitat impacts and mitigation and to include the compensation ratios from the 
MMP and Order. 

Comment 4 (RWQCB]: Mitigation of emergent aquatic vegetation and exotic trees and shrubs must 
be addressed in the EA. 

Answer: Text and tables have been revised to show that impacts on exotic trees and shrubs will be 
actively mitigated, and miniscule impacts on emergent aquatic vegetation (0.001 acre] will be 
passively mitigated. 

Comment 5 (RWQCB]: Since the release of the EA, the Corps has conducted additional field 
assessments to evaluate the extent of potential impacts to the various habitats. The EA and CEQA 
document should be revised to reflect the latest data and include adequate mitigation consistent 
with the 1999 MMP. The latest impact and mitigation evaluation must be submitted to the Regional 
Water Board Executive Officer for review and approval. 

Answer: The EA has been updated to reflect subsequent fieldwork and design refinements to 
decrease impacts and increase mitigation. Mitigation provisions are now consistent with the MMP. 

Comment 6 (RWQCB]: Have the revised design plans and specifications, and the EA, been reviewed 
by the wildlife agencies and Corps Regulatory to ensure compliance with permits? 

Answer: Permitting agencies have been given the opportunity to review the most recent revised 
plans and specifications, and additional agencies have been consulted multiple times during the 
lengthy design process. 

Corps Regulatory does not have jurisdiction over the Reach 12 project given that this is a Corps civil 
works project. The Corps Section 404 permit was requested by and provided to the SCVWD in the 
event that there was no Corps project, and to cover additional work beyond the limits of the Corps 
project in the event that it was authorized by Congress. 

Comment 7 (SCVWD]: The western pond turtle is a California species of special concern and 
therefore is a concern under CEQA. Protective measures should be included. 


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Page f 64 




Answer: This has been coordinated with the SCVWD and will be addressed in the EIR Addendum 
prepared by the SCVWD. Native vertebrates found during construction will be protected to the 
maximum extent feasible. 

Comment 8 (SCVWD]: Clarify and resolve the underseepage issue stated in the draft EA. 

Answer: This issue has been coordinated further and has been removed as a concern. 


7.0 Determination and Statement of Findings 

The USACE has prepared this Final Supplemental EA to assess and disclose the potential impacts of 
the proposed project on the quality of the environment within the proposed project area. Based on 
this assessment, it has determined that with implementation of avoidance, minimization, and 
mitigation measures, the proposed action would not significantly affect the surrounding 
environmental resources. The potential impacts and proposed avoidance, minimization, and 
mitigation measures are summarized in Table 12. Based on these findings, a Finding of No 
Significant Impact [FONSI] has been prepared pursuant to 33 CFR Part 325. 


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Page 165 




8.0 


Documents Incorporated by Reference 


The following documents are incorporated by reference into this Supplemental EA. 


• Final Environmental Impact Report/Environmental Impact Statement for the Upper 
Guadalupe River Flood Control Project (SCVWD and USACE 1999a], 

• Waste Discharge Requirement and Water Quality Certification for the Santa Clara Valley 
Water District and United States Army Corps of Engineers Upper Guadalupe River Flood 
Control Project, City of San Jose, Santa Clara County. Order R2-2003-0115 (San Francisco 
RWQCB 2003] (available in Appendix F], 

• Volume VIII of the FEIR/EIS for the Upper Guadalupe River Flood Control Project— 
Mitigation Monitoring Plan (SCVWD and USACE 1999b], 

• NMFS Supplemental Biological Opinion (NMFS 2005] (available in Appendix E], 


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9.0 


List of Preparers and Contributors 


Name 

Title 

Affiliation 

Years 

Experience 

Preparers 

William Dejager 

Biologist 

USACE 

22 

Cynthia Jo Fowler 

Environmental Manager, 
Ecologist 

USACE 

10 

Tessa Beach 

Environmental Manager, 
Biological Sciences 

USACE 

5 

Richard Stradford 

Archaeologist 

USACE 

30 

Amanda B. Cruz 

Biologist 

USACE 

9 

Kenneth Wong 

Chief, Regional Planning 
Section 

USACE 

11 

Chris Eng 

Environmental Manager 

USACE 

20 

Contributors 

Andrew Smith 

Engineer 

USACE 

5 

Bonievee Delapaz 

Real Estate 

USACE 

8 

James Manitakos 

Environmental Planner II 

SCVWD 

29 

Lotina Nishijima 

Assistant Civil Engineer II 

SCVWD 

11 


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10.0 


References 


City of San Jose. 2014. "Guadalupe River Trail.” Available at: 

http: //www.sanioseca.gov/Facilities/Facility/Details/202 Accessed on March 26, 2014. 

City of San Jose. 2010. Environmental Noise Assessment for Envision San Jose General 2040 Plan. 

County of Santa Clara et al., 2012. Final Santa Clara Valley Habitat Plan, available at 
http://www.scv-habitatplan.org/www/site/alias default/346/final habitat plan.aspx . Accessed 
on April 30, 2014. Additional authors are City of San Jose, City of Morgan Hill, City of Gilroy, Santa 
Clara Valley Water District, and the Santa Clara Valley Transportation Authority. 

Department of Water Resources (DWRJ. 2004. California’s Groundwater. Bulletin 118. Available 
at: http://www.water.ca.gov/pubs/groundwater/bulletin 118/basindescriptions/2- 

9.02.pdf . Accessed on March 20, 2014. 

Dunne and Leopold. 1978. Water in Environmental Planning. W.H. Freeman and Company, New 
York. 

Federal Highway Administration. 2006. Construction Noise Handbook. Available at: 

http: //www.fhwa.dot.gov/environment/noise /construction noise/handbook/ . 

Guadalupe River Park Conservancy. 2012. Flora and Fauna. Available at: 
http: //www.grpg.org/Wildlife.shtml . Accessed on April 3, 2014. 

H.T. Harvey and Associates, 1997. Red-Legged Frog Distribution and Status - 
1997. Prepared for Santa Clara Valley Water District, CA. 

Leidy, R.A., G.S. Becker, B.N. Harvey. 2005. Historical distribution and current status of 

steelhead/rainbow trout (Oncorhynchus mykiss) in streams of the San Francisco Estuary, 
California. Center for Ecosystem Management and Restoration, Oakland, CA. 

NMFS. 2005. Supplemental Biological Opinion for the Upper Guadalupe River Flood Control Project, 
San Jose, California. File No: 151422SWR00SR589 

NMFS. 2010. 5-yer Review: Summary and Evaluation of Central Coastal Steelhead DPS and 
Northern California Steelhead DPS. Available at: 

http://www.nmfs.noaa.gov/pr/pdfs/species/ccc_nc_steelhead_5yearreview.pdf. Accessed 
on April 3, 2014. Accessed on April 15, 2014. 

Paul, M.J. and J.L. Meyer. 2001. Streams in the urban landscape. 


Upper Guadalupe Flood Control Project, Reach 12 

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San Francisco Regional Water Quality Control Board (RWQCB], 2003. Waste Discharge 

Requirement and Water Quality Certification for the Santa Clara Valley Water District and 
United States Army Corps of Engineers Upper Guadalupe River Flood Control Project, City of 
San Jose, Santa Clara County. Order R2-2003-0115. 

San Francisco Bay RWQCB. 2009. Basin Plan Amendment. Available at: 

http://www.epa.gov/waters/tmdldocs/32396 final staff reportpdf . Access on March 12, 
2014. 

Santa Clara Valley Urban Runoff Pollution Prevention Program. Guadalupe Watershed. Available at: 
http: //www.scvurppp-w2k.com/ws guadalupe.shtml . Accessed on March 12, 2014. 

SCVWD. 2011-2013. Upper Guadalupe River Flood Control Project—Continuous Temperature 
Monitoring (2011-2013], Data provided by SCVWD. 

SCVWD. 2012. Upper Guadalupe River Reach 6 Construction Water Quality Monitoring (available 
in Appendix B], 

SCVWD. 2012. Reservoir Operating Restrictions. Available at: 

http://www.valleywater.org/uploadedFiles/Services/CleanReliableWater/WhereDoesYour 

WaterComeFrom/Reservoirs/Operating%20Restriction%20FA0%202011 FINAL 07 05 1 

l.pdf . Accessed on April 2, 2014. 

UC Davis. 2007. California Swainson's Hawk Inventory: 2005-2006. Department of Fish and Game 
Resource Assessment Program, Final Report. Available at: 

https://www.dfg.ca.gov/rap/proiects/swainsonhawk/docs/RAP-final-report-form- 

2007.pdf . Accessed on April 15, 2014. 

USACE. 1996. Engineering Manual 1110-2-1619: Risk-based Analysis for Flood Damage Reduction 
Studies. Available at: 

http://www.publications.usace.army.mil/Portals/76/Publications/EngineerManuals/EM 1 

110-2-1619.pdf . 

USACE. 2009. ETL 1110-2-571: Guidelines for Landscape Planting and Vegetation Management at 
Levees, Floodwalls, Embankment Dams, and Appurtenant Structures. Available at: 
http://www.publications.usace.army.mil/Portals/76/Publications/EngineerTechnicalLette 

rs/ETL 1110-2-571.pdf . 

USACE. 2012. Upper Guadalupe River Reach 10B Construction Water Quality Monitoring (available 
in Appendix B], 

USACE. 2013. Upper Guadalupe River Reach 12 Sampling and Analysis Report. 


Upper Guadalupe Flood Control Project, Reach 12 

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United States Army Corps of Engineers 


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USACE. 2014. Upper Guadalupe River Flood Risk Management Project—Reach 12: Supplemental 
Design Documentation Report (DDR], ITR/BCOES Submittal. January 2014. Prepared by: 
Moffatt & Nichol with ICF Jones & Stocks and McBain & Trush. 

USACE and SCVWD. 1999a. Final Environmental Impact Report / Environmental Impact Statement 
for the Upper Guadalupe River Flood Control Project. 

USACE and SCVWD. 1999b. Volume VIII of the FEIR/EISfor the Upper Guadalupe River Flood Control 
Project—Mitigation Monitoring Plan. 

USEPA. 2010. Watershed Assessment, Tracking & Environmental Results. Available at: 

http://iaspub.epa.gov/tmdl waterslO/attains waterbodv.control?p list id=CAR205400501 

9980928160437&P cvcle=2010&p report type . Accessed on March 20, 2014. 

USFWS Critical Habitat Mapper. Available at: 

http: //crithab.fws.gov/crithab/flex/crithabMapper.isp ?. Accessed on 15 April 2015. 

USFWS. 1998. Recovery Plan for Insect and Plant Taxa from the Santa Cruz Mountains in California. 
http: //ecos.fws.gov/docs/recovery plan/980928a.pdf . Accessed on April 15, 2014. 

USFWS. 2002. Recover Plan for the California Reddegged Frog [Rana aurora draytonii). Available 
at: http://ecos.fws.gov/docs/recovery plan/020528.pdf . Accessed on 15 April 2014. 

USFWS 2008. Lasthenia conjugens (Contra Costa goldfields] 5-year Review: Summary and 
Evaluation. Available at: http://ecos.fws.gov/docs/five year review/docl993.pdf . 
Accessed on 15 April 2014. 

USFWS. 2009a. Species Account, California Tiger Salamander [Ambystoma californiense). Available 
at: http: //www.fws.gov/sacramento/es species/Accounts/Amphibians- 
Reptiles/Documents/California tiger salamander.pdf . Accessed on April 15, 2014. 

USFWS. 2009b. Bay Checkered Butterfly [Euphydryas editha bayensis ] 5-year Review: Summary 
and Evaluation. Available at: http://ecos.fws.gov/docs/five year review/doc2517.pdf . 
Accessed on April 15, 2014. 

USFWS 2010. Chorizanthe robusta var. robusta (Robust Spineflower] 5-year Review: Summary and 
Evaluation. Available at: http://ecos.fws.gov/docs/five year review/doc3229.pdf . 
Accessed on 15 April 2014. 


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USFWS 2013. Dudleya setchelli (Santa Clara Valley Dudleya] and Streptanthus albidus spp. albidus 
(Metcalf Canyon Jewelflower] 5-year Review: Summary and Evaluation. Available at: 
http://ecos.fws.gov/docs/five year review/doc4336.pdf . Accessed on 15 April 2014. 


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FINDING OF NO SIGNIFICANT IMPACT (FONSI) 

(33 CFRpt.230) 


Reach 12 of the Upper Guadalupe Flood Risk Management Project 
Supplemental Environmental Assessment 

1. Introduction : The proposed Reach 12 project is a portion of the federal Upper 
Guadalupe Flood Risk Management Project. The project is located in San Jose, 
Santa Clara County, California. A Supplemental Environmental Assessment (EA) 
was prepared pursuant to 40 CFR § 1502.9(c) to supplement the existing 1999 
final Environmental Impact Statement (EIS) for the federal Upper Guadalupe River 
Flood Control Project. A Supplemental EA is necessary to disclose potential 
impacts not previously identified in the 1999 EIS because changes to the project 
are proposed and considerable vegetation has grown in the project area since the 
release of the 1999 document. 

2. Action : The intent of Reach 12 is to attain multiple beneficial environmental 
objectives while meeting the overall Upper Guadalupe River project’s basic 
purpose of flood risk management. Construction of Reach 12 would improve river 
morphology and provide riparian and shaded riverine aquatic (SRA) cover habitat 
beyond what is required to mitigate for Reach 12 impacts. Additional riparian and 
SRA cover habitat creation would be used to mitigate for impacts resulting from 
construction of other reaches of the Upper Guadalupe River project. 

3. Factors Considered : Factors considered for this FONSI were direct, indirect, and 
cumulative impacts on flood risk management; flows, currents, and circulation; 
ground water; soil quality; water quality; biological resources (including special 
status species); air quality; historic and cultural resources; noise; recreation; 
transportation and traffic; land use; aesthetics; public utilities, facilities, and 
services; and public health and safety. 

4. Conclusion : Based on a review of the information incorporated in the 
Supplemental EA, including views of the United States Army Corps of Engineers 
(USACE) and resource agencies having special expertise or jurisdiction by law, the 
USACE concludes the proposed activity would not significantly affect the quality of 
the physical, biological, and human environment. In addition, avoidance, 
minimization, and mitigation measures are proposed to further support this 
determination. Pursuant to the provisions of the National Environmental Policy 
Act of 1970, the preparation of an additional Environmental Impact Statement 
(EIS) will therefore not be required. 


Approved by: 



J Ul H 


John C. Morrow 
Lieutenant Colonel, U.S. Army 
District Engineer 


Date 


APPENDIX B 


SITE-SPECIFIC BIOLOGICAL EVALUATION 

POTENTIAL OCCURRENCE OF FOUR PROTECTED SPECIES AT 
UPPER GUADALUPE RIVER REACH 12 



Santa Clara Valley 
Water District 


'6 


MEMORANDUM 

FC 14 (01-02-07) 


TO: James Manitakos, Environmental Planer II FROM: W. Douglas Padley, 

Biologist III 


SUBJECT: Site-Specific Biological Evaluation, Potential DATE: June 12, 2014 

Occurrence of Four Protected Species at 
Upper Guadalupe River Reach 12 


On June 4, 2014 I received the non-SMP Biological Services Request Task No 1321. This task item 
requested a review of the species indicated as potentially present on Reach 12 of the Guadalupe River 
based on the Santa Clara Valley Habitat Plan species maps. The task requested a reach specific 
evaluation of habitat conditions that support or refute the generalized species mapping in the Valley 
Habitat Plan. The species included in this review are: California red-legged frog ( Rana draytonii), 
foothill yellow-legged frog ( Rana boylii), western pond turtle ( Actinemys marmorata), and tricolored 
blackbird ( Agelaius tricolor). 

This investigation was conducted using a wide variety of data sources and a field visit. Data sources 
included Santa Clara Valley Water District technical reports, the California Natural Diversity Data Base, 
surveys conducted by the Santa Clara Valley Water District and others, The Santa Clara County 
Breeding Bird Atlas (Bouseman, 2007), phone interviews with local ornithologists and individuals 
involved in the monitoring of tricolored blackbirds. 

Reach 12 of the Guadalupe River extends from Branham Lane to Blossom Hill Road. Vegetation along 
the Guadalupe River includes a narrow band of red willows ( Salix laevigata) and sandbar willows ( Salix 
exigua) interspersed with Fremont cottonwoods ( Populus fremontii), box elder (Acer negundo), 
elderberry ( Sambucus Mexicana) alder ( Alnus sp.), annual and perennial grasslands and coyote brush 
(Baccharis pilularis). In addition to the native vegetation listed above, there are numerous non-native 
species present along the Guadalupe River Reach 12 including Incess cedar ( Calocedrus decurrens), 
black walnut ( Juglans californica ), apricot ( Prunus armeniaca), palo verde (Cercidium sp), stone pine 
(.Pinus pinea), and eucalyptus ( Eucalyptus sp). The wetted channel is relatively narrow (less than 20 
feet across) and the River is confined by levees. A relatively low elevation terrace is present on the 
east side of the river between the wetted channel and the levee. The vegetation on the terrace is 
primarily annual grassland with stands of fennel. The creek bottom is primarily gravel and wetland 
vegetation in the form of cattails ( Typha latifolia) and willow herbs ( Epilobium sp.) are present along the 
channel margins. Non-native trees and shrubs are located downstream of the percolation ponds and 
may be escaped vegetation from adjacent housing and commercial land uses. 

Above and beyond the top of bank (levees) the river is bordered by retail commercial development and 
percolation ponds on the west side and by residential, retail commercial, and percolation ponds on the 
east side of the river. The last portion of previously undeveloped land on the west side of the river is 
being actively developed as a commercial retail center at this time. California Highway 85 crosses the 
Guadalupe River Reach 12 at approximately the midpoint of Reach 12. The percolation ponds on 
either side of the Guadalupe River are maintained free of emergent vegetation and the pond slopes are 
also vegetation free. The percolation ponds are being drained and groomed in 2014. A bicycle path 
borders the Guadalupe River on the east side from Chynoweth Ave. upstream to the north side of the 
percolation pond and from the south side of the percolation pond upstream to Blossom Hill Road. 




There are no tributaries along the Guadalupe River Reach 12. Ross Creek is located downstream of 
the Branham Lane and the confluence of Alamitos Creek and Guadalupe Creek is located upstream of 
Blossom Hill Road. A grade control structure is located upstream of Blossom Hill Road and this 
structure includes a fish ladder. 

There is no continuous road access along the Guadalupe River Reach 12. Access on the east side is 
blocked downstream of Chynoweth Ave by landscape vegetation. On the west side of the river the 
access is blocked downstream of the percolation ponds. The area under and around Branham Lane 
has been used off and on as a homeless encampment for at least 15 years. 

California red-legged frogs 

The Santa Clara Valley Water District has conducted and contracted for numerous surveys of California 
red-legged frogs along the Guadalupe River including Reach 12 and in the vicinity. Areas surveyed 
include Ross Creek, Guadalupe Creek, Alamitos Creek, the Alamitos Percolation Ponds, the 
Guadalupe Percolation Ponds, the Hillsdale drop structure, Stream Gauge 23B, and the Alamitos Drop 
Structure. No California red-legged frogs have been found on the Guadalupe River in Reach 12 or in 
the Guadalupe River upstream or downstream of Reach 12. The nearest known location of California 
red-legged frogs is located on Guadalupe Creek in the vicinity of Guadalupe Dam 6 miles upstream 
California Department of Fish and Wildlife Rarefind, California red-legged frog record no 420; Rarefind 
5 (accessed online June 12, 2014 at https://map.dfg.ca.gov/rarefind/view/RareFind.aspx). 

Jones and Stokes Inc conducted surveys on the Guadalupe River for the Upper Guadalupe River Flood 
Control Project in the late 1990’s (Jones and Stokes Associates, Inc. 1998). The surveys did not 
identify California red-legged frogs in the project vicinity. Based on these surveys the US Fish and 
Wildlife Service (USFWS) issued a letter of determination of not likely to adversely affect the frog 
(USFWS 1998). 

Since the construction of the Downtown Guadalupe River Flood Control Project the District has 
conducted annual steelhead and Chinook salmon redd surveys in the Guadalupe River and its 
tributaries. These surveys have been conducted by District fisheries biologists familiar with and have 
experience conducting California red-legged frog surveys. No California red-legged frogs have been 
observed in the Guadalupe River, including Reach 12, or in the tributaries in the immediate vicinity. 

In addition to California red-legged frog surveys, the District commissioned a report on the status and 
distribution of California red-legged frogs in Santa Clara County (Jennings et al. 1997). This report 
identified historic records of California red-legged frog based on museum specimens, and identified 
areas where the species was presumed extant and presumed extinct. The delineation of the presumed 
extinct and presumed extant regions was based on a wide variety of data including the history of land 
use, current land use, surveys for the species, habitat availability, and species requirements. The 
Guadalupe River Reach 12 is located in the area presumed extinct. 

The District contracted with the Coyote Creek Riparian Station to conduct a biological stream inventory 
of the Guadalupe River (Bernhard et al 1997). The reptile and amphibian portion of this study focused 
on the tributary creeks rather than the mainstem of the Guadalupe River. No California red-legged 
frogs were observed on the tributary creeks in the vicinity of Guadalupe River Reach 12. 

The District conducts stream maintenance activities throughout Santa Clara County. Since 2001 the 
District has been conducting these activities using a programmatic approach. The District and USFWS 
agreed the California red-legged frog has been nearly eliminated from urban areas and the Guadalupe 
River is located in a highly urbanized area (USFWS 2001). The District updated the stream 
maintenance program and obtained permits for the program from regulatory agencies including the 
USFWS in 2014. USFWS agreed the California red-legged frog was extirpated from the urban areas of 
Santa Clara County which includes Reach 12 of the Guadalupe River (USFWS 2014). 



The USFWS designated critical habitat and published a recovery plan for the California red-legged frog 
(USFWS 2001, and USFWS 2002). There is no critical habitat in the vicinity of the Guadalupe River 
Reach 12 and no core recovery areas in the Guadalupe River Watershed. 

The likelihood of California red-legged frogs occurring on the Guadalupe River in Reach 12 is very 
small. The habitat conditions are not suitable to sustain a population of California red-legged frogs due 
to lack of upland habitat, roads, urban development and intensive use of the riparian corridor by 
humans, feral cats, raccoons and other predators. The riparian woodland is restricted to the immediate 
banks of the Guadalupe River and does not extend beyond the top of the bank. In 2014 the extreme 
drought in the region has caused the Guadalupe River in Reach 12 to go dry. The adjacent percolation 
ponds are drying and the bottoms of the ponds will be groomed by the District. When water was 
present in the river, there were populations of predatory fish species including black bass ( Micropterus 
sp.), bluegill ( Lepomis macrochirus), and steelhead ( Oncorhynchus mykiss). In addition to the fish, 
non-native amphibians and reptiles are present in the creek and these may be predators and 
competitors with California red-legged frogs. Bullfrogs ( Rana catesbeiana), and various turtles 
including red-eared sliders ( Trachemys scripta) are regularly observed in the project vicinity. Aquatic 
rodents have also been observed in the Guadalupe River in the vicinity of Reach 12. Muskrats 
(Ondontra zibethica) feed in the creek and reduce vegetation cover that may be used by California red- 
legged frogs. Beavers (Castor canadensis) recently moved into the area and is may be reducing 
canopy cover by felling trees. While beaver dams may increase the habitat suitability for California red- 
legged frogs, the local beavers have not constructed any dams. 

In addition to the District, Army Corps of Engineers, and other professional biologists conducting 
surveys in the Guadalupe River, the public heavily uses the Guadalupe River corridor in Reach 12. 
Local activists regularly survey the river for the presence of rare or sensitive biological resources. The 
California Department of Fish and Wildlife wardens patrol the Guadalupe River, and the City of San 
Jose Park Rangers also regularly patrol along the Guadalupe River in the vicinity of Reach 12. None of 
these groups have reported the presence of California red-legged frogs in the vicinity of Reach 12. 

There is very low potential for the California red-legged frog to occur at Reach 12. 

Foothill yellow legged frog 

The District has not conducted surveys specifically for the foothill yellow-legged frog, however the 
District has conducted surveys for California red-legged frogs throughout the District and these surveys 
include the identification of all amphibians and reptiles encountered. Foothill yellow-legged frogs have 
not been identified during these surveys in the Guadalupe River. The nearest known location of foothill 
yellow-legged frogs is from the base of Guadalupe Dam approximately 6 miles upstream from the 
project site (California Department of Fish and Wildlife Rarefind, foothill yellow-legged frog record no 
736; Rarefind 5 accessed online June 12, 2014 at https://map.dfq.ca.gov/rarefind/view/RareFind.aspx) . 

Jones and Stokes Inc conducted surveys on the Guadalupe River the Upper Guadalupe River Flood 
Control Project in the late 1990’s (Jones and Stokes Associates, Inc. 1998). The surveys did not 
identify any foothill yellow-legged frogs in the project vicinity. 

Since the construction of the Downtown Guadalupe River Flood Control Project the District has 
conducted annual steelhead and Chinook salmon redd surveys in the Guadalupe River and its 
tributaries. These surveys have been conducted by District fisheries biologists familiar with foothill 
yellow-legged frog. No foothill yellow-legged frogs have been observed in the Guadalupe River 
including Reach 12, or in the tributaries in the immediate vicinity. 

The District contracted with the Coyote Creek Riparian Station to conduct a biological stream inventory 
of the Guadalupe River (Bernhard et al 1997). The reptile and amphibian portion of this study focused 




on the tributary creeks rather than the mainstem of the Guadalupe River. No foothill yellow-legged 
frogs were observed on the tributary creeks in the vicinity of Guadalupe River Reach 12. 

The mixture of riparian woodlands and open annual grasslands along the Guadalupe River is 
appropriate for foothill yellow-legged frogs. However, the lack of uplands adjacent to the Guadalupe 
River in Reach 12 reduces the suitability of the river in this section. Gravel and cobble sized rock are 
found within the Guadalupe River in Reach 12 but it is unclear how much of this is embedded in finer 
materials and unavailable to the foothill yellow-legged frogs. 

Foothill yellow-legged frogs are susceptible to predation by fish and birds. The Guadalupe River in 
Reach 12 supports black bass, bluegill, carp, steelhead and other species which may prey on the frogs. 
In addition, a variety of predatory birds are also present in Reach 12 including common merganser 
(.Mergus merganser), and at least species of herons and egrets. The percolation ponds adjacent to the 
river may not provide safe haven either. The sycamores (Platanus racemosa) in the Alamitos 
Percolation Ponds are a major roost site for double-crested cormorants ( Phalacrocoraxauritus). 

The District commissioned a report on the status and distribution of foothill yellow-legged frogs in Santa 
Clara County in 1999 (Jennings et al. 1999). This report looked at historic records including specimens 
in museums to identify areas where the foothill yellow-legged frogs were likely to be found and where 
they were not likely to be found. In this report the entire Guadalupe Watershed was considered an area 
where foothill yellow-legged frogs had been extirpated. 

The District conducts stream maintenance activities throughout Santa Clara County. Since 2001 the 
District has been conducting these activities using a programmatic approach. As part of the best 
management practices the District conducts pre-construction surveys for sensitive species when 
appropriate. The pre-construction surveys include sensitive amphibian and reptile surveys. The pre¬ 
construction surveys conducted between 2001 and 2014 have not identified foothill yellow-legged frogs 
on the Guadalupe River or on tributaries in the vicinity of the Guadalupe River Reach 12. 

The likelihood of foothill yellow-legged frogs occurring on the Guadalupe River in Reach 12 is very 
small. The habitat conditions are not suitable to sustain a population of foothill yellow-legged frogs due 
to lack of upland habitat, roads, urban development and intensive use of the riparian corridor by 
humans, feral cats, raccoons and other predators. The riparian woodland is restricted to the immediate 
banks of the Guadalupe River and does not extend beyond the top of the bank. In 2014 the extreme 
drought in the region has caused the Guadalupe River in Reach 12 to go dry. The adjacent percolation 
ponds are drying and the bottoms of the ponds will be groomed by the District. When water was 
present in the river, there were populations of predatory fish species including black bass, bluegill, and 
steelhead. In addition to the fish, non-native amphibians and reptiles are present in the creek and 
these may be predators and competitors with foothill yellow-legged frogs. Bullfrogs, and various turtles 
including red-eared sliders are regularly observed in the project vicinity. Aquatic rodents have also 
been observed in the Guadalupe River in the vicinity of Reach 12. Beavers recently moved into the 
area and is may be reducing canopy cover by felling trees. While beaver dams may increase the 
habitat suitability for foothill yellow-legged frogs, the local beavers have not constructed any dams. 

In addition to the District, Army Corps of Engineers, and other professional biologists conducting 
surveys in the Guadalupe River, the public heavily uses the Guadalupe River corridor in Reach 12. 
Local activists regularly survey the river for the presence of rare or sensitive biological resources. The 
California Department of Fish and Wildlife wardens patrol the Guadalupe River, and the City of San 
Jose Park Rangers also regularly patrol along the Guadalupe River in the vicinity of Reach 12. The 
District is has not heard from any of these groups about the presence of foothill yellow-legged frogs in 
the vicinity of the flood control project. There is very low potential for the foothill yellow-legged frog to 
occur at Reach 12. 


Western Pond Turtle 



The western pond turtle probably uses the Guadalupe River Reach 12 on an occasional basis to move 
between areas with more suitable habitat. California Department of Fish and Wildlife Rarefind records 
and District data show a pattern of use by western pond turtles in the Guadalupe River Watershed 
(California Department of Fish and Wildlife Rarefind, western pond turtle record nos 104, 301, 303, and 
304; Rarefind 5 accessed online June 12, 2014 at https://map.dfg.ca.gov/rarefind/view/RareFind.aspx ). 
Western pond turtles have been observed upstream and downstream of Reach 12 but no records have 
been identified in reach 12. 

In addition to the records listed above the District has conducted surveys for sensitive amphibians and 
reptiles in the Guadalupe River and the tributary creeks. The District has observed western pond 
turtles in Alamitos Creek upstream of Lake Alamitos and in the vicinity of the Almaden Drop Structure 
(SCVWD unpublished data). 

The District commissioned a report on the status and distribution of the western pond turtle in Santa 
Clara County in 1999 (Jennings et al. 1999). This report looked at historic records including specimens 
in museums to identify areas where the western pond turtles were likely to be found and where they 
were not likely to be found. In this report the entire Guadalupe Watershed was considered an area 
where western pond turtles were presumed extant. 

The western pond turtle probably uses the Guadalupe River Reach 12 on an occasional basis. The 
river is probably used as a movement corridor rather than as habitat for prolonged periods of time. The 
lack of significant pool habitat within the creek probably reduces the habitat suitability for the western 
pond turtle in the river. While the percolation ponds adjacent to the Guadalupe River may provide 
some additional aquatic habitat, the overall lack of suitable upland habitat in Reach 12 probably 
precludes the western pond turtle from using the reach as a breeding site. 

Tricolored Blackbirds 

The tricolored blackbirds use emergent wetland vegetation and shrubby upland plants for nesting 
substrate. Bulrush (Schoeneoplectus califbrnicus), and Himalayan blackberry (Rubus armeniacus) are 
used for nest sites. Agricultural operations within foraging distance may be important components of 
the habitat. These habitat components are significantly reduced or absent in the Guadalupe River 
Reach 12. 

California Department of Fish and Wildlife Rarefind records and District data suggest the species is not 
present along the Guadalupe River Reach 12. The nearest record for tricolored blackbirds is at the 
base of Calero Dam 8 miles upstream from the project site.(California Department of Fish and Wildlife 
Rarefind, tricolored blackbird record no 171; Rarefind 5 accessed online June 12, 2014 at 
https://maD.dfa.ca.aov/rarefind/view/RareFind.aspx ). It is unclear if nesting was actually taking place at 
this site. The site was abandoned by the birds 10 days later. The other Rarefind records are from the 
Pajaro Watershed in southern Santa Clara County. District records are limited to mid-winter sightings 
adjacent to San Francisco Bay. 

Scott Frazier (Pers. Comm.. June 12, 2014) indicated the populations of tricolored blackbirds continue 
to decline throughout the state and recommended looking at data on the tricolored blackbird portal. 

The 2011 tricolored blackbird triennial survey indicates no birds were observed in Santa Clara County 
in 2011 (accessed on June 12, 2014 at 

http://ca.audubon.org/sites/default/files/documents/audubon_2011_survey_report_final.pdf). The 
results for 2014 have not been posted to the internet; however Bob Meese (pers. Comm. June 12, 
2014) wrote that no birds were observed in the county during the April 2014 triennial survey but 600 
birds were observed at Calero Reservoir on June 7, 2014. 



In addition to the District, Army Corps of Engineers, and other professional biologists conducting 
surveys in the Guadalupe River, the public heavily uses the Guadalupe River corridor in Reach 12. 
Local activists regularly survey the river for the presence of rare or sensitive biological resources. The 
California Department of Fish and Wildlife wardens patrol the Guadalupe River, and the City of San 
Jose Park Rangers also regularly patrol along the Guadalupe River in the vicinity of Reach 12. The 
District is has not heard from any of these groups about the presence of tricolored blackbirds in the 
vicinity of the flood control project. 

Roving bands of tricolored blackbirds may forage in the vicinity of the Guadalupe River Reach 12 but 
larger areas of suitable habitat are present upstream and downstream of Reach 12 and tricolored 
blackbirds are not observed in these areas. The potential for tricolored blackbird to use the Guadalupe 
River Reach 12 is very low due to lack of sufficient suitable habitat. 

Literature Cited: 

Bernhard, J. C. Fischer, N. Pelkey, C. Preuss. 1997. Guadalupe River Watershed Stream Resources 
Inventory Summary Report. Volume one of two. Coyote Creek Riparian Station. 1997. 

Bousman, W. G. 2007. Breeding bird atlas of Santa Clara County, California. Santa Clara Valley 
Audubon Society, Cupertino. 

Jones and Stokes Associates, Inc. 1998. California red-legged frog survey results for the Upper 
Guadalupe River Flood Control Project, San Jose, California. Jones and Stokes Associates, Inc. 
Sacramento. 

Jennings, M.R., S. Townsend, and R. Duke. 1997. Santa Clara Valley Water District: California Red- 
legged Frog Distribution and Status, 1997. H. T. Harvey and Associates. 

Jennings, M.R., R.R. Duke, G.E. Flohr, T.P. Haney, and P.A. Hartman. 1999. Santa Clara Valley 
Water District Foothill Yellow-legged Frog Distribution and Status -1999. H.T. Harvey and 
Associates. 13 p. 

Jennings, M.R., R.R. Duke, G.E. Flohr, T.P. Haney, and P.A. Hartman. 1999. Santa Clara Valley 
Water District Western Pond Turtle Distribution and Status -1999. H.T. Harvey and Associates. 

18 p + appendices. 

USFWS. 1998. Proposed Upper Guadalupe River Flood Control Project, Santa Clara County, 
California. USFWS, Sacramento. 2 p. 

USFWS. 2001. Formal Endangered Species Consultation on the Santa Clara Valley Water District 
Ten-Year Maintenance Permit, PN 22525s. USFWS Sacramento, 50 p. 

USFWS. 2014. Programmatic Formal Endangered Species Consultation on the Santa Clara Valley 
Water District Stream Maintenance Program in Santa Clara County, California. USFWS 
Sacramento. 70 p. 



W. Douglas Padley 


WD Padley, L. Porcella 
WDP 

Guadalupe_Reach_12_Sensitive_Tech_Memo6-7-14.docx