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SJVDP LIBRARY 







San Joaquin Valley Drainage Program 



TlCllilMnC^lL 

OCTOBER 1988 



FORMULATING AND EVALUATING 

DRAINAGE MANAGEMENT PLANS FOR 

THE SAN JOAQUIN VALLEY 



The San Joaquin Valley Drainage Program was established in mid-19a4 

"ldli?rse'rv'ice Tw^'i''^ '^\ '"^^'" '' Reclamation, U.s" Hsh' nd 
Vnd rll ^f^y^'U-S.. Geological Survey, California Department of Fish 
and Game, and California Department of Water Resources. The purposes of 
the Program are to investigate the problems associated with the drainaSe 
of irrigated agricultural lands in the San Joaquin Valley and to 
formulate, evaluate, and recommend alternatives for the immediate and 
long-term management of those problems. immediate and 

v.ocoJI1k%'^®5°'"^ ^f °1® °^ several Program technical reports present i no 
research findings to date and implications on specific topics such a? 
geohydrology of the San Joaquin and Tulare Lake Basins fi'sh and 
wildlife resources, public health, agricultural setting d ann^na 
methods and drainage water treatment, reuse, and disposal The data 

eJal St?nTdUinJ" '\''' ''''''^' ''' ^^^"9 used in%o?mulat ng and 
nl^n^ wh?.h !-??^K "^^^'^ management options and preliminary alternative 
plans, which will be presented in a separate report in late 1988 a 

be'comn?S?rH T'^^i?? '''''' ''''' ''''''' ^"^ al?ernl iie pi ns wilt 
.nH Jl^.l ^^Jm'' P"^^'^ ''^^'^ ^" ^^^ ^^11 °^ 1989- Final study resu Us 

nnarr^SorJln ll.l%T^'ll%l'r '''' '^ '''''^''' '^ ''^ ^-^''-'^ 
directTto:^' concerning the San Joaquin Valley Drainage Program may be 

San Joaquin Valley Drainage Program 

2800 Cottage Way, Room W-2143 
Sacramento, California 95825-1898 



TECHNICAL REPORT 



FORMULATING AND EVALUATING 
DRAINAGE MANAGEMENT PLANS FOR 
THE SAN JOAQUIN VALLEY 



By 



Donald G. Swain, Consulting Resources Planner 

Craig M. Stroh, U. S. Bureau of Reclamation 

Nigel W. T. Quinn, Cornell University 

Steven Kasower, California Department of Water Resources 

Robert L. Horton, U. S. Bureau of Reclamation 



San Joaquin Valley Drainage Program 
Interagency Study Team 



October 1988 



TABLE OF CONTENTS 

Page 

EXECUTIVE SUMMARY vii 

I. INTRODUCTION 1 

Purpose and Scope of Report 1 

Valley Drainage and Drainage-Related Problems 2 

Previous Planning Efforts 3 

Current Program Efforts 4 

II. IMPROVED DATA BASE 7 

Source, Mobility, and Occurrence of Trace Elements 7 

Ground-Water Hydrology 9 

Geographic Extent, Nature, and Severity of Contamination 11 

Toxic Effects of Trace Elements on Fish and Wildlife 12 

Potential Risks to Public Health 14 

Irrigation and Drainage Management 16 

Drainage Water Treatment 16 

III. ANALYTICAL TOOLS AND PROCEDURES 19 

Westside Agricultural Drainage Economics (WADE) Model 20 

Hydrosalinity Model 24 

Hydrologic Studies Supporting the WADE Model 28 

Ground-Water Flow Model of the Panoche and 

Cantua Fan Area 30 

Hydrologic-Economic Model 32 

Ground-Water and Salinity Management Model 33 

Broadview Agricultural Return Flow Model 34 

Water Use Survey of Agricultural Lands in 

Western San Joaquin Valley 35 

Investigation of Ground-Water Flow into 

Subsurface Drains 36 

Potential Use of Ground-Water Pumping for 

Water Table Management 37 

Seepage Losses from On-Farm Distribution Systems. . . 38 

Analysis Using a Geographic Information System. ... 38 
Surface Water Network Model for the Grasslands 

Drainage Basin 39 

San Joaquin River Model 40 

San Joaquin Valley Agricultural Production Model 40 

Economic Studies Supporting the WADE Model 41 

Irrigation Technology Adoption/Diffusion Model ... 42 
On-Farm Decisionmaking under Salinity 

Conditions Model 42 



- iix - 



Page 

Additional Economic Analysis 44 

Economic Analysis of Environmental Impacts 45 

Farm Profitability Distribution Analysis 48 

Economics of Health Risk Assessment 49 

Financial Analysis: Public/Private Cost Sharing 49 

Regional Economic Analysis . . . . - 51 

Impact Analysis 51 

Input-Output Analysis 51 

Social Analysis 52 

Purpose and Objectives 52 

General Approach 53 

Tools and Methods 56 

Use of Social Analysis 57 

Institutional Analysis 58 

Overview of Institutional Setting 58 

Relationship to Drainage Problems and Issues 59 

Implementing Change 50 

IV. PLANNING PROCESS 61 

Problem Identification and Program Objectives 62 

Present Conditions 63 

Future without Coordinated and Comprehensive Action 63 

Identification of Management Options and Estimation of Effects ... 67 

Management Options 73 

Allocation of available water supply 74 

Changes in water cost 74 

Changes in irrigation technology 75 

Changes in land use 75 

Drainage discharge limit 76 

Drainage effluent fee 76 

Drainage treatment for selenium removal 75 

Disposal of drainage water 77 

Analysis of Options 77 

Evaluation Criteria 80 

Effectiveness in Accomplishing Objectives 81 

Technical Feasibility 81 

Implementation 82 

Economic Efficiency and Effects 82 

Cost Allocation and Cost-Sharing 82 

Risk Assessment 83 

Environmental Performance 83 

Institutional and Legal Performance 83 

- iv - 



Page 

Social Effects 83 

Irreversible Commitments and Irretrievable Adverse Effects. . . 84 

Unavoidable Adverse Effects 84 

Evaluation and Screening of Options 84 

Formulation of Alternative Plans and Estimation of Their Effects . . 85 

Plan Analysis 88 

Display of Plan Effects 91 

Evaluation of Alternative Plan Effects 91 

Review and Involvement 92 

Technical Review 92 

Local Advisory Groups 93 

Public Involvement 93 

Policy Review and Action 93 

REFERENCES. 95 

GLOSSARY 103 



- V - 



TABLES 
No. Page 

III-l Comparison of Model Characteristics 31 

IV-1 Grasslands Subarea, Year 2010 

Future-Without Scenario 65 

IV-2 Alternative Management Options under Consideration by the 

San Joaquin Valley Drainage Program - July 1988 68 

IV-3 Sources of Information on Agricultural 

Drainage Management Options 72 

IV-4 How Options are Analyzed by the WADE Model 79 

IV-5 Off stream Water Storage on Wetlands 86 



FIGURES 



i-1 Planning Subareas viii 

I-l Planning Process 1 

1-2 Planning Process - Identify Drainage and 

Drainage-Related Problems 3 

II-l Planning Process - Improved Data Base 7 

II-l Planning Process - Analytical Models and Procedures 19 

11-2 Polygon Cell Map for Grasslands Subarea 22 

11-3 Sequence of operation in the WADE Model 23 

:iI-4 Cell Polygon in WADE Model 25 

11-5 Hydrologic Models Relating to the WADE Model 29 

II-6 Economic Analysis Diagram 46 

11-7 Social Analysis Diagram 55 

IV-1 Planning Process - Planning Criteria 51 

IV-2 Conceptual Framework for Comparing Effects of Action 64 

IV-3 Projected Effects of Alternative Plans 90 



- VI - 



FORMULATING AND EVALUATING DRAINAGE 
MANAGEMENT PLANS FOR THE SAN JOAQUIN VALLEY 

EXECUTIVE SUMMARY 

This report describes the planning process being used by the San Joaquin 
Valley Drainage Program as a series of steps beginning with the identification 
of all contributing factors to valley drainage and drainage-related problems 
and culminating in the recommendation of site-specific plans for the valley 
subareas shown in Figure i-1. The report also illustrates how the Program's 
analytical methods can be used in developing and evaluating preliminary plans 
for these subareas. 

DATA BASE 

Current Program investigations are identifying the extent and impact of 
contributing factors to valley drainage and drainage-related problems and 
potential solutions. This research is focusing on specific geohydrologic 
conditions in the valley, toxic effects of drainage water trace elements on 
fish and wildlife, potential drainage-related risks to public health, 
irrigation and drainage technology, and drainage water treatment. The data 
from these investigations provide the foundation for establishing parameters 
to formulate and evaluate options as potential features of alternative 
management plans to solve valley drainage and drainage-related problems. 

ANALYTICAL TOOLS AND PROCEDURES 

Analytical studies being conducted by the Drainage Program are developing 
computer models and other tools for use in the planning process. Sophisticated 
data management methods are required because of the large size of the study 



- Vll - 



FIGURE i-1 



San Joaquin Valley Drainage Program 
Subarea Boundaries 



I u d f A r e e 
IK SU91IIC* 
AND S U 9 A « C ;^ 
NOS SUSilirA 

SUBAIfA 
U8AICA 



t 




- Vlll - 



area, the complexity of the problems and potential solutions, and the quantity 
and quality of information available for different subareas of the valley. 

The Westside Agricultural Drainage Economics (WADE) model is the most 
comprehensive of the Drainage Program's mathematical models and is designed to 
interact with several detailed economic and hydrologic models available from 
the U.S. Geological Survey, U.S. Department of Agriculture, California 
Department of Water Resources, University of California, and numerous Program 
contractors. These models represent three types in terms of their 
relationship to the WADE model: Data files that supply direct input to WADE, 
algorithms that help improve the manner in which the model simulates the 
western valley hydrology, and output verification used to check for 
consistency of results and to assist in calibration of the WADE model. 

The WADE model can be considered as two interacting models: 

An agricultural production model which simulates cropping decisions, 
farm profit and revenue, and water management technology selection, 

A hydrosal inity model which estimates the effects of these management 
decisions on the water table, salinization in the crop root zone, and 
drainage water quantity and quality. 

The agricultural production model and the hydrosal inity model interact 
sequentially. That is, the hydrosal inity model provides data to the 
agricultural model such as depth to ground water, drainage flow and quality, 
and salt concentrations in the root zone and semi -confined aquifer. The 
production model then solves for cropping, irrigation, and other management 
choices to maximize farm income under the given constraints. The resulting 
data on surface water application, ground-water and drainage water pumping, 
crops grown by soil type, irrigation technologies used, deep percolation, and 
other relevant information are then fed back to the hydrosal inity model. 

- ix - 



For the WADE model analysis, the total study area has been divided into 
more than 180 geographic areas described as "polygon cells," representing 
distinct homogeneous soil and drainage characteristics. Four vertical soil 
layers are included in the hydrosalinity model from the crop root zone to 
below the Corcoran clay layer. 

Other major analytical investigations being conducted for the Program are 
financial, social, environmental, and institutional analysis. The information 
provided by these investigations is used in evaluating methods to implement 
alternative plans. 

PLANNING PROCESS 

In the plan formulation process, the Drainage Program and its advisors 
are developing alternative plans that address the principal Program concerns 
of agricultural productivity, fish and wildlife resources, water quality, and 
public health. These are formulated through a combination of professional 
judgment, experience with the subject area, and from analyses of model runs. 

The planning process is being conducted in two phases: The development 
and evaluation of the effects of management options and preliminary plans, and 
the refinement and evaluation of the effects of detailed alternative plans. 
The first phase will be reported on in the Program's Alternative Plans Report 
scheduled later this year. Potential management options identified to date 
include approximately 60 structural and nonstructural approaches which have 
been organized in six interrelated categories: (1) Institutional and 
regulatory changes, (2) source control (including water conservation, drainage 
management, ground-water management, crop management, and alternative land 
use), (3) drainage treatment, (4) drainage reuse, (5) drainage disposal, and 
(6) fish and wildlife management measures. 

- X - 



Alternative management plans are being formulated and evaluated using the 
following criteria: 

Effectiveness in accomplishing objectives, 

Economic efficiency and effects, 

Cost allocation and cost-sharing, 

Risk assessment, 

Environmental performance, 

Institutional and legal performance, 

Social effects, 

Irreversible and irretrievable committment of resources, and 

Unavoidable adverse effects. 

Each plan is assessed on how well it meets these criteria and comparisons 
are made among the plans. The results of these comparisons will provide the 
basis for recommending one or more plans for each subarea. 

To illustrate how Program planning methods and analytical tools are being 
used in analyzing options and formulating alternative plans, six steps are 
described for the planning process: 

1. Identification of drainage and drainage-related problems (both current 
and projected future conditions without a coordinated and 
comprehensive plan). A set of "future-without" conditions will serve 
as a baseline for comparison of alternative plans. 

2. Identification of potential management options to achieve Program 
objectives and estimation of their effects. 

3. Preliminary evaluation of options using the evaluation criteria 
identified above. 

4. Formulation of alternative plans (combination of options) for each of 
the five planning subareas and estimation of effects. To display and 



- XI - 



evaluate the effects of alternative plans, the Program is using the 
four accounts described in the Federal Economic and Environmental 
Principles and Guidelines for Water and Related Land Resources 
Implementation Studies . These accounts are: National Economic 
Development, Environmental Quality, Regional Economic Development, and 
Other Social Effects. 

5. Evaluation of alternative plans using criteria referred to in step 3. 

6. Recommendation of plan(s) (not discussed in this report). 
This process is iterative and steps 4 and 5 will be repeated, as 

necessary, to further refine plans in light of new information and knowledge 
related to plan effects. 

REMAINING ACTIVITIES 

Much work remains to be accomplished before the Drainage Program 
concludes in 1990. The activities necessary to complete development and 
calibration of several of the analytical models that support the WADE model 
are expected to be completed during the next 6-9 months. Scenarios will be 
developed for the five subareas with the assistance of representatives of 
local interests to serve as the basis for formulating alternative plans. 
Plans will include details of the features such as descriptions of operating 
criteria, feature interrelationships, and costs for each subarea. 

Currently, the data available for Program planning purposes are most 
extensive for: (1) Grasslands Subarea, followed by (2) Westlands, (3) Tulare, 
(4) Kern, and (5) Northern Subarea. The Alternative Plans Report, scheduled 
for completion later this year, will reflect the available analytical results 
to that time for each of the subareas. 



- xil - 



CHAPTER I 
INTRODUCTION 

PURPOSE AND SCOPE OF REPORT 

This report describes the planning process that is being used by the 
San Joaquin Valley Drainage Program in formulating and evaluating alternative 
plans for the management of valley agricultural drainage and drainage-related 
problems. The planning process, as shown in Figure I-l, follows a series of 
steps beginning with the identification of all contributing factors to valley 



PLANNING PROCESS 



Identify Drainage 
and Drainage- 
Related Problems 



Improve Data Base 

Source. Mobility , and 

Avail, of Trace Elements 
Ground-Water Hydrology 
Geog. Extent. Nature, and 

Severity of Contaminants 
Toxic Effects of Trace 

Elements on Fish 

and Wildlife 
Potential Risks to 

PubUc Healtli 
Irrigauon and Drainage 

.Mgmi. Technology 
Drainage Water Treatment 



Identify Potential 
Manajgement Options 
and Effects 

Institutional Changes 
Source Control 
Drainage Treatment 
Drainage Reuse 
Drainage Disposal 
Fish and Wildlife 
.Management 



Apply Evaluation Criteria 

Effectiveness 
Economic Efficiency 
Cost Allocation/Sharing 
Risli Assessment 
Environmental Performance 
Institutional Feasibility 
Social Effects 

Irreversible/Irretrievable Effects 
Unavoidable .Adverse Effects 



Evaluate and 
Screen Options 



H 



Formulate Alt. 
Plans and 
Estimate Effects 



Develop Analytical 
Models & Procedures 



Hydrological .Analysis 
Agricultural Productivity 
Fish and Wildlife Resources 
Health Risk Assessment 
Financial Analysis 
Regional Economics 
Social Factors 
Insututional Analysis 



Iterative Process 



Evaluate Effects of 
Alternative Plans 



Recommend Plans 



Revised 9/88 



FIGURE I-l - Planning Process. The Drainage Program planning 
process follows a series of steps beginning with the identification 
of all contributing factors to valley drainage and drainage-related 
problems and culminating in the recommendation of subarea plans. 
To assist the reader in following the process and the details 
involved in the steps, the planning process figure and brief 
descriptions appear at the beginning of appropriate sections of 
this report. 



drainage and drainage-related problems and culminating in the recommendation 
of site-specific plans for valley subareas. The report also illustrates how 
the Program's analytical methods can be used in developing and evaluating 
plans for these valley subareas. 

Specifically, the purposes of this report are to: 

Describe the concepts and process used by the Drainage Program in plan 

formulation and evaluation, 
Illustrate the use of hydrologic and economic analytical tools to 

address valley agricultural drainage and drainage-related problems, 
Describe analytical tools currently being developed to address the 
environmental, social, institutional, and financial aspects of these 
problems, 
Discuss baseline conditions which would likely occur in the absence of 
comprehensive, coordinated action to solve valley drainage and 
drainage-related problems, 
Assess the options which are being considered as features for 

alternative plans, and 
Outline the steps to be undertaken in developing alternative plans for 
subareas of the San Joaquin Valley. 

VALLEY DRAINAGE AND DRAINAGE-RELATED PROBLEMS 

Problems associated with drainage of irrigated agricultural lands on the 
west side of the San Joaquin Valley are most easily understood in terms of the 
need for and the impacts resulting from subsurface agricultural drainage. The 
use of installed subsurface drains allows irrigation water to leach high salt 
concentrations from semi-pervious, slow draining soils. These salts, which 
threaten the productivity of irrigated agriculture in the valley, also include 



toxic and potentially toxic trace 
elements such as selenium which are 
then concentrated in the subsurface 
drainage water. Negative impacts, 
however, have been associated with 
the storage and disposal of this 
subsurface agricultural drainage 
including degradation of surface- 
and ground-water quality, 
contamination of fish and wildlife 
habitats, and potential risk to 
public health. 



Idenlifv Drainage 
and Dramaee- 
Related Problems 




PLANNING PROCESS 



Improi^ DsU Base 

Source, MobDur. md 

AviU. r,f Tiac« Elemooa 
Ground- Wil«r UydnDtogjr 
Ccog- Extent. Natun, tnd 

S«vcncy o( ConuniiDims 
Tojuc Elfeco ot Traw 

EkowMJ on Fbh 

and WiLdofe 
PtneooiJ Riiki la 

Pubic Heafth 
Impooo uhJ Drainage 

Mfmi. T«ichnolo{T 
Dramage W>ref Trtatjpgrn 



IdeoOry Potenliii 
MaiuMmenl Options 
end LTiecls 

Source Ciniral 
Diaiiu^ Tr«*ur«nl 
DraiDi^-e Reus< 
Druofltr^ DiEpoul 
Fi%b *nU WddJi/o 
M3na(»mem 



Apply EvalualtOQ Crtteha 

EnetU«eneii 
EcoflomK EiTicieoqr 
Q'jt AJJocauoiWShAnot 

EnvuT'niTMniJ Peilomunce 
iootuuofial FeacibUitf 
Sociil E fleets 

inpveiiiblo/Ineineoble EUecu 
UMvoidable Ad»*rM EiJea» 



Evaluate and 
ScrecD Opt ions 



Formulate Alt. 
rtans and 
Estimsie Effects 



Evniiiale Effects uf 
AHenuU've Plans 



Develop Analytical 
^fodeta & Proc7dui«« 



llydn>logicaI Aq*Jvbu 
ApKuUiual Produttjvirr 
f«h and WTUliU fiejoorcM 

Fm^aciil Anjivsw 
RtponaJ Econotnics 
StKmi Fauon 
InsHuiioiul Aiuirw 



Recommend Plans 



[tcr^iive Process 



Revised 9/S8 



FIGURE 1-2 - Identify Drainage and 
Drainage-Related Problems. This part of 
Chapter I discusses valley drainage and 
drainage-related problems, previous plan- 
ning efforts, and current Program efforts, 
setting the stage for the analyses and 
plan formulation discussions that follow. 



PREVIOUS PLANNING EFFORTS 

Studies have been conducted over the past several decades by public and 
private researchers and planners seeking a technically feasible, economically 
justified, environmentally sound, and politically acceptable approach to 
managing agricultural drainage problems on the west side of the San Joaquin 
Valley. Efforts to provide for appropriate management of subsurface 
agricultural drainage on the west side of the valley have been documented 
since the early 1920's. 

Several Federal and State studies conducted from the 1950' s through the 
1970' s recommended construction of a master drain to remove saline drainage 
water from the San Joaquin Valley through the western Sacramento-San Joaquin 
Delta for disposal to the Pacific Ocean. An investigation begun in the early 
1980's was designed to provide necessary analysis to complete planning for a 
master drain. This work was to address safeguards for protection of lands and 



- 3 



water supplies along the drain alignment as a prerequisite to obtaining 
Federal funding for construction of the drain. 

The 1983 discovery of migratory-bird deaths and deformities linked to 
selenium concentrations in agricultural drainage, however, required a total 
reassessment of impacts associated with disposal of agricultural drainage. 

CURRENT PROGRAM EFFORTS 

The need to address toxic constituents in drainage water has complicated 
the drainage issues significantly beyond just "salt disposal." The complexity 
of the problems has required expanding the process used in formulating and 
evaluating alternatives for drainage management. The analytical methods 
developed for the Drainage Program allow consideration of site-specific 
geology and water-quality characteristics of various subareas of the valley 
and the role of individual growers and water districts in reducing 
agricultural drainage water at the source. 

Because of the complexity of the factors contributing to valley drainage 
and drainage-related problems and potential solutions, the Drainage Program is 
currently developing more sophisticated tools including computer simulation 
models. These analytical models are used to organize the extensive data 
available to the Program and to anticipate the effects of decisions at the 
local and on-farm level and to forecast how the use of various management 
options can contribute to solving drainage and drainage-related problems. 
These management options, or plan features, include (but are not limited to) 
irrigation practices and technology, cropping patterns, water reallocation, 
institutional and regulatory approaches, and efforts to combine agricultural 
and wetlands management into mutually supporting plans. While the emphasis of 
the current effort focuses on nonstructural management options, structural 



features will be considered and integrated in the development of plans as 
appropriate. 

The Drainage Program is being conducted as a cooperative Federal -State 
effort to provide for comprehensive planning as well as serve as a framework 
for recognizing non-Program decisions and actions to help provide effective 
and equitable solutions to valley drainage and drainage-related problems. 



- 5 - 



CHAPTER II 
IMPROVED DATA BASE 



During the process of 
establishing the Drainage Program 
goals and objectives, critical data 
needs were identified to help in 
defining all contributing factors 
to valley drainage problems and 
potential solutions. Subsequently, 
significant work has been devoted 
to identifying specific data 
requirements and conducting 
research to meet those needs. This 
chapter discusses some of the 
investigations underway and how the 
improved data base contributes to plan formulation and evaluation. Detailed 
research findings and implications are contained in Program technical reports 
which address specific topics such as the valley agricultural setting; 
drainage water treatment, reuse, and disposal; San Joaquin Basin geohydrology; 
Tulare Basin geohydrology; fish and wildlife resources; and public health. 













PLANNING PROCESS 














Idealirv Dramage 
and Drainage- 
Related Pixtblems 








Apply EvalulMD Cnteiia 

EnfcLiencM 
Ecooamic Elfitieocy 
- Coji AUocauoo'StinDf 
Rjik A«Mimem 
EnvuTffimcnuI Pertonnante 
iDsOunK-fiat f eaiibiliif 
Socijl Effeos 

Idrveiu&leJinvtrMirabIc Etiecu 
Ufiavoidablw Ad«<rw EtIecLi 














„t 






' 








Improve Data Base 

Soutce, Mubiliiv. Jnd 

Avail ol Ttace Ek-menis 
Ground-Waier Hydrologv 
Gcog Exicnt, \aiure, and 

Seveniv ul Coniamiranii 
Toxic Ellecii o( Tface 

Elemenii on Fi'.h 

itid Wildlilv 
Poieniial tUih* lu 

Ptjblic HuMh 
Irrmaiion and Dtjinage 

M^i Technology 




IdeoUfy Polenlul 
MBiMiEemenI Opttoos 
snd hTfects 








f 




1 




— 


Evahiat« Qnd 
Screen Opltoa* 




1 i>«uiu<i<'nal Chani^ 
DrtiMje Treiimtm 

DtWMW DttpOiiJ 

Fiifa 4nO WiMJiJfl 
Management 


i 




♦t 




» 






formula le All. 
Hans aod^_ 
EjiinMie Effects 




Evalakle Effects of 
AitenuUve Plans 










i 














1! 




f 












De^tlop AnalvUcttl 
Models & Procedures 






" 




AsnojUural ProdVKUvity 

Fuf, aod WiidbU RcmorCM 
Health PJih, A.S'^aStnent 
Firiancijl AtuftTiS 

S-mM f jQora 
bmnuliotiil AhaJtsi* 




Recoflnnend Plans 























lieraiive PtoceiS 

Revised y/85 


. 


FIGURE II-l - Improved Data Base. This 
chapter discusses some of the research 
being conducted on valley drainage and 
drainage-related problems and how the 
improved data base contributes to plan 
formulation and evaluation. 




■ 





SOURCE, MOBILITY, AND OCCURRENCE OF TRACE ELEMENTS 

Geohydrologic research being conducted for the Drainage Program is 
designed to increase our knowledge of the source, mobility, and occurrence of 
selenium, other trace elements, and salts in valley soils, ground water, and 
streams. Although selenium has been the focus of much of the Drainage Program 
research because of its documented toxic effects on wildlife at Kesterson 

- 7 - 



Reservoir, other potential drainage water contaminants are also being studied 
including arsenic, molybdenum, chromium, and boron. The results of this 
research are being used in the assessment of alternatives for managing 
subsurface agricultural drainage. 

Most of the selenium and other soluble salts now in the ground water have 
been leached from soils by decades of irrigation which commenced in the early 
1900's and developed sporadically throughout the valley until the 1950's when 
more intensive irrigated agriculture began. The highest ground-water 
concentrations of selenium coincide with highly saline soil derived from the 
marine sedimentary rocks of the Coast Range alluvium. The highest soil 
salinity occurs along the eastern and outer margins of alluvial fans of Coast 
Range streams, where soils have the finest texture, streamflow is infrequent, 
and evaporation of near-surface ground water concentrates trace elements and 
salts in the upper soils. 

As a result of decades of irrigation, the water table has risen at rates 
of 1 to 3 feet per year in many places. Rising ground-water levels during the 
past decade have resulted in a substantial increase in the land area 
experiencing shallow ground-water' levels (0 to 5 feet below ground surface) 
requiring artificial drainage during at least part of the year. 

Evidence from ground-water surveys indicates that irrigation in recent 
years has added less selenium to the ground water than In previous years, most 
soluble soil selenium having already been leached to the underlying ground 
water. Irrigation during the 1950's and 1960's has created a ground-water 
zone with high selenium and salt concentrations lying from about 30 to 150 
feet below the land surface beneath much of the Grasslands and Westlands 
subareas. The quality of the ground water both above and below this highly 
saline zone is more suitable for agriculture and fish and wildlife and less 



likely to contribute to contamination problems if drained or removed through 
pumping. 

Several management alternatives are suggested by these research findings 
on selenium distribution in ground water. For example, the concentration and 
distribution of ground-wcter selenium (as well as any other contaminants which 
adversely effect beneficial uses) may suggest potential locations for 
treatment facilities, the degree of treatment needed, opportunities and 
priorities for water-table control, and areas where changes in agricultural 
practices or technology would be the most effective. 

Most selenium remaining in surface soils of irrigated land is relatively 
resistant to leaching. Current soil concentrations have a wide range from 
about 1 to over 100 parts per million (ppm) depending on such factors as the 
original soil salinity and how long the areas have been irrigated and drained. 
This leach-resistant selenium represents a long-term source in these soils 
since only a fraction of the remaining selenium will be leached in any 
particular year. 

GROUND-WATER HYDROLOGY 

Quantitative data on the ground-water flow system provide the necessary 
information to estimate how effective various irrigation reduction or recharge 
strategies may be in controlling ground-water levels. These data are also 
used to predict locations and mobility rates of high salt and selenium 
concentrations in ground water. A steady-state model of the ground-water flow 
system at key intervals has been developed to integrate data now being 
collected on texture and permeability with historical ground-water data. This 
research provides the physical parameters to model future system behavior. 

The ground-water flow system is not in equilibrium throughout the valley. 
Where the Corcoran Clay layer is present, it divides the flow system into an 

- 9 - 



upper semiconf ined zone and a lower confined zone. Three types of 
hydrogeologic conditions occur above the Corcoran Clay in different parts of 
the valley: Coast Range alluvium, Sierran sand, and flood-basin deposits. 
These soil conditions differ in texture, hydrologic properties, and oxidation- 
reduction state. 

The development of irrigated agriculture in the central part of the 
western valley has significantly altered the flow system. Percolation of 
irrigation water past crop roots has caused the upper water table to rise in 
midfan and distal fan areas. Historical pumping of ground water has lowered 
the piezometric surface of the confined ground-water zone (below the Corcoran 
Clay) by hundreds of feet over a large area of the western valley and has 
lowered the water table up to hundreds of feet in fan head areas and along the 
rim of the valley at the Coast Range. The combination of percolation from and 
pumping by irrigated agriculture has also created a substantial downward 
hydraulic head gradient over a large part of the western valley. This 
condition has been developing in the lower ground-water system at the same 
time that percolation of irrigation water beyond root zones has been slowly 
filling the ground-water system from the top. 

Findings to date suggest some implications for management of the 
hydrologic system. For example: 

The depth and spacing of on-farm drains control the depth at which 
ground water is intercepted. Shallow, close spacing tends to remove 
ground water with lower selenium concentrations from the upper zone. 
Traditional depth and spacing of drains (about 5 to 8 feet deep, 
spaced about 200 to 500 feet apart) remove water from greater depths 
with higher concentrations of selenium because flow lines extend 
deeper within the aquifers and displace water with higher selenium 
concentrations into the drains. 

- 10 - 



Pumping to lower the level of shallow groundwater causing drainage 
problems may also produce the long-term effect of shifting downward, 
permanently, the highly contaminated zone of groundwater that is 
contributing most of the contaminant load to farm drains. 

Temporary control of the water table may be possible in some areas by 
pumping low-selenium ground water from the deeper parts of the ground- 
water system, causing increased downward flow and a general lowering 
of the water table. 

The large volume of high-selenium water present in the upper part of 
the ground-water system from approximately 20 to 160 feet below the 
land surface suggests the desirability of management practices which 
isolate this water from surface soils and from good quality water in 
aquifer zones below the Corcoran Clay layer. 

Complete findings and conclusions on valley geohydrology and geochemistry 
are available in papers and reports published periodically by the USGS on 
specific studies and the Drainage Program's technical reports on geohydrology 
in the San Joaquin and Tulare Basins currently pending publication. 

GEOGRAPHIC EXTENT, NATURE, AND SEVERITY OF CONTAMINATION 

Kesterson Reservoir continues to serve as a significant example of the 
contamination of valley fish and wildlife resources by agricultural drainage. 
Selenium levels in fish and wildlife and important food-chain organisms 
at Kesterson Reservoir remain elevated (above normal background levels for 
species in uncontaminated areas) despite termination of drainage water 
deliveries in the summer of 1986. Dead adult birds continue to be found at 
the reservoir. The tri -colored blackbird (an Endangered Species list 
candidate that uses Kesterson Reservoir for roosting and nesting) experienced 
almost a total nesting failure in 1986 and a low success rate in 1987 although 

- 11 - 



no specific cause has been determined. Endangered San Joaquin kit foxes have 
been observed in Kesterson Reservoir and surrounding lands. 

Results of studies to date also indicate more widespread contamination of 
valley fish and wildlife resources than earlier believed. Elevated levels of 
selenium have been found in aquatic insects and waterfowl eggs in wetlands in 
the Grasslands area, even two years after drainage water was no longer being 
applied. Elevated levels of arsenic, boron, and selenium have also been found 
in fish, migratory birds, and aquatic plants and insects in evaporation ponds 
in the Tulare Lake Basin. 

Several comprehensive field surveys and related assessments have been 
completed of the effects of agricultural drainage contamination on valley 
wildlife, and other studies are ongoing. A computerized data base has been 
developed which includes contaminant residue data for fish and wildlife, and 
other biological tissues, collected throughout the San Joaquin Valley. 

This research is providing critical information on the geographic extent 
and severity of contamination including insights on measures to prevent 
resource contamination problems from expanding and appropriate methods for 
restoring the habitat to a desirable quality. Complete findings and 
conclusions from investigations and' research to date are included in the 
Drainage Program's technical report on fish and wildlife resources now pending 
publ ication. 

TOXIC EFFECTS OF TRACE ELEMENTS ON FISH AND WILDLIFE 

Diet appears to be the most important exposure pathway for selenium 
uptake by fish and wildlife. Organic selenium in the diet (the chemical form 
commonly found in wildlife food-chain organisms) appears to be much more toxic 
to a broad variety of fish and wildlife species than selenate or selenite. 
The toxicity of selenium is dependent upon its chemical form and varies for 

- 12 - 



different species of fish and wildlife. Mallards appear to both take up and 
lose selenium quite rapidly (in a matter of weeks). 

Studies have shown that very low dietary dosages of organic selenium {8, 
16, and 20 ppm dry weight, respectively) can result in adverse effects upon 
reproduction, and physiol?gical and biochemical changes in adult mallards, and 
growth of mallard ducklings. Organic selenium fed to chinook salmon (0 0.92 
mg/g dry weight body wt/day) can result in reduced growth, impaired migratory 
behavior, and damage to organs. Organic selenium at less than 1 ppm in the 
water is acutely toxic to daphnia (aquatic invertebrate - part of diet of 
young fish). Selenium concentrations in water and food chain organisms 
exceeding these levels have been found in many areas on the westside and 
southern end of the San Joaquin Valley. 

In addition to selenium, San Joaquin Valley fish and wildlife are 
presently exposed to toxic levels of other agricultural drainage water 
contaminants including boron, arsenic, and chromium. Understanding both safe 
and toxic concentrations of such contaminants in the environment and diet of 
fish and wildlife has been greatly improved through research conducted during 
the last several field seasons. In addition, a major search and evaluation of 
toxicological literature (including unpublished findings of ongoing research) 
was recently completed to identify safe and toxic thresholds of several 
contaminants in agricultural drainage water. Information from field work, the 
literature review, and other information included in the technical report on 
fish and wildlife resources will be used in establishing parameters for 
evaluating the potential impacts of drainage management alternatives on fish 
and wildlife resources. 

Current and planned research efforts are focusing on the independent 
effects of contaminants other than selenium and on the interactive effects of 
multiple contaminants. Recent studies have shown for the first time that 

- 13 - 



boron in the diet (at 900 ppm dry weight) can adversely affect wildlife, 
including mallard reproduction and possibly growth of mallard ducklings. 
Boron concentrations in some vegetation collected from Kesterson Reservoir 
exceed that level . 

Dietary dosages of arsenic as low as 30 ppm dry weight have also been 
shown to result in adverse effects on the growth of mallard ducklings. 
Arsenic concentrations in vegetation collected from soliie evaporation ponds in 
the Tulare Lake Basin exceed that level. Studies have recently been initiated 
to determine if waterfowl exposure to drainage contaminants in evaporation 
ponds undermines the ability of the birds to resist disease. 

Another current study is documenting use of San Joaquin Valley 
agroforestry plantations by wildlife and determining whether agroforestry 
sites provide safe habitat in terms of contaminant accumulation from drainage 
water. In addition, the potential economic values of wildlife associated with 
such woodlots are being assessed. This information will be used in evaluating 
the potential use of agroforestry as an alternative in managing agricultural 
drainage water. 

POTENTIAL RISKS TO PUBLIC HEALTH 

High levels of selenium detected in fish, wildlife, and plants raised 
concerns about potential health risks associated with drainage water. As a 
precaution, public health warnings have been issued twice during the last 
2-3 years by the California Department of Health Services advising pregnant 
women and young children to avoid or limit consumption of fish and waterfowl 
collected in the Kesterson Reservoir, and the Grasslands Drainage and Tulare 
Subareas. 

In 1985, a scientific-medical committee established by the Merced County 
Health Department completed an assessment of potential health risks associated 

- 14 - 



with Kesterson Reservoir. The assessment concluded that there was no evidence 
of toxic effects to residents of the Kesterson area. Because of the limited 
available data and information at that time, the committee recommended further 
environmental and public health monitoring throughout the process of cleaning 
up Kesterson. 

Since 1985, health surveys have been conducted of local residents, 
workers in the Kesterson refuge area, and foragers in the Kesterson and 
Grasslands areas. Samples of drainage water, ground water, air, vegetation, 
domestic animals, and wildlife have been collected to assess any potential 
public health problems. The Department of Health Services completed a report 
in mid-1987 presenting public health implications of elevated selenium levels 
in the valley, specifically Merced County and the area surrounding Kesterson 
National Wildlife Refuge. Investigative activities by various agencies were 
summarized and assessed in the report. 

In general, the report found that studies to date have indicated no 
adverse health effects on local residents, but concluded that levels of 
selenium in fish, aquatic birds, and waterfowl could be unsafe for 
unrestricted human consumption. Data on drinking water, livestock, animal 
products, and air particulates did not suggest a high level of exposure. 
Because of the limitations in existing data, the Department of Health Services 
has recommended further studies be conducted to make a conclusive assessment 
of potential health risks. 

Additional investigations being undertaken for the Drainage Program 
include ethnographic surveys of high-risk populations in the Kesterson area. 
These surveys will assess the food consumption patterns of various local 
population groups, including foraging habits and locally grown food products 
that make up part of the diet of local residents. The expanded studies will 
include a market basket survey for the general population outside the 

- 15 - 



immediate area to provide data necessary to help assure protection of public 
health from potential adverse impacts associated with agricultural drainage 
water. The Drainage Program's technical report on public health concerns 
related to valley drainage (August 1988) discusses all information from public 
health studies conducted to date and includes information on selenium and 
other drainage-water constituents which may be a health risk. 

IRRIGATION AND DRAINAGE MANAGEMENT 

Improved irrigation and drainage management techniques have been 
estimated to reduce total drainage water volume by as much as two-thirds on 
individual valley farms. Among the most promising on-farm techniques 
identified to date for drainage reduction are precise scheduling of 
irrigation, improving water application uniformity, recirculating field runoff 
(tailwater), and reusing subsurface drainage water where possible. 

Because of differences in local soil and ground-water conditions, the 
appropriateness, practicality, and cost-effectiveness of specific practices 
vary within individual fields and from farm to farm. Field research and 
demonstration efforts are investigating the relative effectiveness of various 
irrigation and drainage options and refining the information for use in 
formulating and evaluating plans for specific valley subareas. 

DRAINAGE WATER TREATMENT 

In addressing the particular drainage problems of the San Joaquin Valley, 
the Drainage Program has examined numerous treatment processes specific to 
removal of selenium, total dissolved solids, and other substances of concern 
in valley drainage water. Of those evaluated to date, eight processes have 
demonstrated the best potential for possible use in the valley: Bacterial 
treatment, iron-filing adsorption, iron-hydroxide precipitation, microalgal 

- 16 - 



bacterial treatment, ion-exchange resins, in-situ volatilization from soil, 
chemical/physical attenuation in soil, and reverse osmosis. Detailed 
discussions of these processes are included in the Program's technical report 
on drainage water treatment. Information on the relative costs and efficiency 
in removing drainage water contaminants is being used in the plan formulation 
process to evaluate these processes as potential management options to solve 
valley drainage and drainage-related problems. 



17 - 



CHAPTER III 
ANALYTICAL TOOLS AND PROCEDURES 



Analytical studies are being 
conducted by the Drainage Program 
to develop computer models and 
other tools to assist in 
formulating and evaluating 
alternative management plans to 
solve valley drainage and drainage- 
related probl ems . Sophisticated 
data management methods are 
required because of the large size 
of the study area, the complexity 
of the problem, and the quantity 
and quality of information 



PLANNING PROCESS 



IdenlH^ Drainage 



Improve Data Base 

S<n^«c. MobUuv. aod 

Avtif. 'A Tiate ElMnwai 
Ground- Water Hytirokia 
G«og. L««n. NoruT*. And 

S«»«rtn o( ConiiraiDMitB 
ToiQC £ffeco of Trace 

£I«(n«DQ on Ftsh 
' and WrUbk 
PotsnU&j Risks [o 

PuWic He»Rh 
tmf^ooa uid Dtatnage 

Mpjxi. Technolojy 
E>ratnagt WitCf Tttitrpfm 



IdeDliTy Potwillal, 



[(MJtutktnai Chinees 
SouicQ Comrol 
Druoace Tra^uncoi 

DcttiMce Dupou) 

Fiib *7Kl WiMUe 

MaueBfRem 



Apply Evaloatioo Crit«Tia 

EcoaoiDic EtftciwjCT 
Cos Allocaoo(wSb4noe 
Risk A«e:>unem 
Efivtn>nmeQUl Palonnaiwe 
Io«ituiiwifll f eaiibdHy 
Social Efftfco 

(Joavoidable Advene Effects 



Ponnulale Alt. 
Plans and 
Estuuaie EftecLs 



Develop Analytical 
Models & Procedures 

Hydfoloycal Analvsii 
Aericuliiiial Pcoduciiviiv 
Fuh and wadlile Resources 
Health Rjsk Asseismeni 
Financial Analytu 
Re^onai Economics 
Social Facion 
Insuiutional Analv^i^ 



Evalaale EfTeds of 
AheniaUve Plans 



Recommrnd Huis 



lietaiive Proc«s 



FIGURE III-l - Analytical Models and Proce- 
dures. The Drainage Program is conducting 
analytical studies to develop models and 
other tools for formulating and evaluating 
alternative plans. 



available for different subareas of the valley. Computer models have been 
developed to assess the implications of various on-farm and wetland management 
decisions in terms of both economics and hydrology under current valley 
conditions. These conditions include rising water tables and drainage return 
flows which contain high concentrations of selenium and other toxic and 
potentially toxic trace elements. 

The planning models being developed range from on-farm studies which use 
field-specific data, to regional models which aggregate information to the 
water district level and can be used in assessing response to decisions on a 
regional basis. The models will help determine the cause-effect relationships 
of different actions which can be expected to occur with or without 



19 



implementation of a coordinated, comprehensive action plan to solve valley 
drainage problems. 

Planning models and other analytical tools are being developed for six 
subject areas: Hydrologic analysis (including quantity and quality aspects), 
economic analysis (including agricultural production and valuation of fish and 
wildlife resources), financial analysis, regional economic analysis, social 
analysis, and institutional analysis. These tools are described in this 
chapter beginning with the Westside Agricultural Drainage Economics (WADE) 
model which is the most comprehensive of the Drainage Program's mathematical 
models and combines hydrologic and economic aspects. The WADE discussion is 
followed by descriptions of supporting economic and hydrologic studies which 
are being used by the Program to enhance the predictive capability of the WADE 
model. The section on economic analysis also includes studies that are not 
directly related to (but which complement) the WADE model. The four other 
major areas of analysis discussed in this chapter are financial, regional 
economic, social, and institutional analysis. 

WESTSIDE AGRICULTURAL DRAINAGE ECONOMICS (WADE) MODEL 

The WADE model, based on a previous study by Horner and Dudek (1985), 
can be considered as two interacting models. One is the San Joaquin 
Agricultural Production Model which simulates cropping decisions, farm revenue 
and profit, and water management technology selection. The other is a 
hydrosal inity model which estimates the effects of these management decisions 
on the water table, salinization in the crop root zone, and drainage quantity 
and qual ity. 

The hydrosal inity portion of the WADE model has recently been expanded to 
include the management of both private and public wildlife habitat areas. 
Modifications to integrate the operation of wildlife habitat areas into the 

- 20 - 



agricultural production model are being considered. The fundamental 
assumption of the agricultural production model is that growers behave in ways 
to maximize profits, and it is uncertain whether an analogous assumption is 
relevant for wildlife habitat managers, particularly managers of public areas. 

The current economic and hydrologic models that together comprise the 
WADE model are the result of an extensive review of existing modeling 
literature and both formal and informal peer review. A detailed description 
of the WADE model is being prepared for formal review in January 1989 by the 
National Research Council's Committee on Irrigation-Induced Water Quality 
Problems (one of several advisory groups to the Drainage Program.) 

WADE is a regional model covering the entire west side of the San Joaquin 
Valley. For the purposes of the Program's analyses, the study area has been 
divided into more than 180 "polygon" cells each representing distinct 
homogeneous soil and drainage characteristics. Study area cell maps delineate 
areas with common characteristics based on the direct association between 
these characteristics and agricultural productivity and yields established in 
the Horner and Dudek study. Figure III-2 is an example of a polygon cell map 
for the Grasslands Subarea. By using a computer-based Geographic Information 
System, information developed for water district areas or other local or 
regional boundaries can be displayed on the cell map. Similarly, information 
developed for the cells in the WADE model can be projected on specific local 
bases as desired. 

As illustrated in Figure III-3, the WADE agricultural production and 
hydrosalinity models interact sequentially. That is, the hydrosal inity model 
provides data to the agricultural model on the depth to ground water, drainage 
flow and quality, and salt concentrations in the root zone and in the semi- 
confined aquifer. The production model then solves for cropping, irrigation, 
and other management choices that maximize farm income under the given 

- 21 - 



Figure III-2 

BOUNDARIES OF POLYGON CELLS 

AND WATER DISTRICT AREAS IN 

GRASSLANDS SUBAREA 



MUSTANG WO 




WADE MODEL POLYGON 
CELL BOUNDARIES 

GRASSLANDS SUBAREA BOUNDARY 

WATER DISTRICT BOUNDARIES 



- 22 - 



Figure III-3 



SEQUENCE OF OPERATIONS IN THE WADE MODEL 



Starting Conditions 



Aquifer Levels 

Salinity of GW and Root Zone 
Root Zone Moisture 
Hydrologic and Soil Parameters 



I 




Winter Agricultural Production Model 
Predicts: 

§8 Crop Wetland Acres 

°° Irrigation Technology Choice 

§8 Drainage Installation 

S§ Applied Water 

§§ Groundwater Pumping 

§s ET 



I 



Winter Hydrosalinity Model 



\ 




C Costs I 

Constraints 1 



Summer Agricultural Production Model 
Predicts: 
- Yields 
°° Farm Income 
°° Crop Acres 
" Irrigation Technologies 
§§ Applied Water 
~ Groundwater Pumping 
§g EX 



^SWVMAAftw^ 







Summer Hydrosalinity Model 



"!a&^^ -J^lsl 384C!3»MJ<a^*i 



- 23 - 



constraints. The resulting data on surface water application, ground-water 
and drainage water pumping, crops grown by soil type, irrigation technologies 
used, drains installed, deep percolation, and other relevant information are 
then fed back to the hydrosal inity model. 

HYDROSALINITY MODEL 

The hydrosal inity model is used to predict drainage quantity and quality 
in the WADE model by establishing relationships between irrigation system 
performance and deep percolation, between deep percolation and flow into 
subsurface drains, and between constituent load and drainage discharge. Four 
vertical soil layers shown in Figure III-4 are included in the hydrosal inity 
model: (1) The crop root zone, (2) a layer which extends from the bottom of 
the root zone to 20 feet below the ground surface, (3) the unconfined/semi - 
confined aquifer zone which ends at the upper surface of the Corcoran Clay 
layer, and (4) a confined aquifer zone which represents sub-Corcoran storage. 

Irrigation hydrology is simulated by allocating all water applied to a 
field among four uses, or fates: evapotranspiration, deep percolation, 
runoff, and evaporative loss. The simulation is presently conducted for seven 
types of irrigation practices and two levels of irrigation water management. 
The practices are furrow irrigation with 1/4-mile and 1/2-mile rows, furrow 
irrigation with a recycle system, border strip, drip, and hand-move sprinkler 
systems. Irrigation management is considered either average or well managed 
based on water use efficiency and distribution uniformity. The simulation 
technique also accounts for differences in the proportion of crop 
evapotranspiration that is met by pre-season and regular season irrigation 
applications for various crops. Two 5-month intervals are simulated by the 
model for October through March (preseason) and April through September 
(regular season). Use of two seasonal intervals allows the hydrologic 

- 24 - 



Figure III-4 



WADE HYDROLOGY MODEL 



Applied 
Water 



PERCOLATION TO 
GROUNDWATER 



Canal 
Seepage 



. Crop 
a ET 



Evaporative losses from 
Distribution System 



GROUNDWATER 
PUMPING 




VERTICAL FLOW 
BETWEEN LAYERS 



Corcoran 
Clay Layer 




Drainage 
Contribution Zone 



Remaining 

Unconfined or 

Semi-Confined 

Aquifer 



Confined Aquifer 



Runoff 



TILE DRAINAGE 
FLOWS 



LATERAL SUBSURFACE 

FLOW BETWEEN 

ADJACENT CELLS 




CELL POLYGON IN WADE MODEL 



Agricultural production model interacts with the hydrology model 
to provide water application, cropping and irrigation and drainage technology decisions. 



- 25 - 



implications of various combinations of crops and irrigation systems to be 
evaluated in the model without significantly adding to the size of the model 
or greatly increasing execution time. The current data base does not support 
using a smaller time-step in the regional -scale model. To ensure that the 
WADE model adequately captures seasonal hydrology, the results of intensive 
field-level studies of irrigation scheduling, drainage, and root zone salinity 
response have been incorporated into the distribution fractions and 
hydrosal inity model . 

The hydrosal inity model performs mass balance calculations within each of 
the four subsurface soil layers for both water and total dissolved solids 
(TDS). The model uses parameter values estimated in a detailed regional flow 
model by the U.S. Geological Survey (USGS) for approximately approximately 
450,000 acres within the Grasslands and Westlands Subareas. These include 
aquifer characteristic parameter values for horizontal and vertical hydraulic 
conductivity and flow, and vertical leakage between layers in the saturated 
aquifer. Aquifer hydraulic properties for areas outside the region studied by 
the USGS are being estimated from parameter values obtained from the 
California Department of Water Resources' ground-water Hydrologic-Economic 
Model (discussed later in this chapter), from a previous USGS study by 
Williamson and others (1985), and from available well logs. 

The WADE model calculates salt concentration (TDS) in the root zone for 
both winter and summer periods for each polygon cell. Salt migration out of 
the root zone of a cell into the ground water is assumed to be dependent on 
net water movement out of the root zone layer. These seasonal salt fluxes 
include accumulated salts in the root zone due to irrigation and solubilized 
gypsum which results from natural weathering of soils. A piston-flow 
algorithm is used to calculate the concentration of deep percolation from the 
root zone. Gates and Grismer (1988) have developed algorithms for estimating 

- 26 - 



these salt fluxes and for estimating both mineral precipitation and gypsum 
solubilization in the root zone. These algorithms have been incorporated in 
the WADE model . 

Downward movement of salts into the deeper aquifer is dependent on 
vertical flow between the 20-foot layer and deeper aquifer layers and any 
lateral inflow or outflow between the cell and adjacent cells. Lateral flows 
between adjacent polygon cells are determined by applying Darcy's Law between 
adjacent cell centers. The hydraulic gradient and mean horizontal hydraulic 
conductivity are used to calculate these lateral flows. An effective flow 
cross-section is calculated in cases where the flow vector {magnitude and 
direction) is not at right angles to the common boundary between cells. 

Drainage quantity and quality estimates for the cells during each 5-month 
season simulated by the model are calculated using an algorithm which 
considers the total area drained, water application rates for each polygon 
cell, and the elevation of the water table. Most salts in drainage water are 
assumed to derive from the layer which extends from the water table to the 
20-foot depth contour. The concentration of salts in drainage flows for each 
polygon cell is computed by volume weighting the proportion of flows from both 
the shallow (saturated to 20 feet) layer and the deep (20 feet to top of 
Corcoran) aquifer layer. Field level data is available to permit an 
approximation to be made of the average proportions of these flows for certain 
polygon cells and for known drainage system depths, spacing, and various 
irrigation management/cropping combinations. 

Concentrations of selenium and boron in drainage water can be estimated 
from the relationships that have been developed between TDS and these 
constituents in drainage flows. Research to date, conducted by the Geological 
Survey for the Drainage Program, has indicated good correlation between TDS 
and both boron and selenium. 

- 27 - 



The WADE model is currently being calibrated to reproduce historic 
drainage flows and drainage flow quality for each polygon cell. Three sites 
have been chosen for calibration -- the drained area within the 42,000 acre 
area of Westlands Water District, Broadview Water District, and Panoche Water 
District -- all of which have good records of drainage installation and have 
data on drainage flows and quality for a number of years. 

Large variation in groundwater TDS within individual polygon cells make 
it extremely difficult to make reliable predictions of trace element 
concentrations. Simulation model runs are therefore used to assess the 
relative impact (rather than determine absolute values) of various policy 
alternatives on drainage quality. 

Hydroloqic Studies Supporting the WADE Model 

Detailed hydrologic studies are being used in the planning process to 
improve our understanding of some of the mechanisms which control complex 
hydrologic processes observed in the study area and to assess the reliability 
of model predictions in light of the spatial variability of soil and aquifer 
properties known to exist on the west side of the San Joaquin Valley. 

These studies can be classified by three types in terms of their 
relationship to the WADE model: (1) Data files that supply direct input to 
the WADE model, (2) algorithms that help improve the manner in which the model 
simulates the western valley hydrology, and (3) output verification used to 
check for consistency of results and to assist in calibration of the WADE 
model. The detailed hydrological studies being conducted for, or providing 
information used by, the Drainage Program are listed below and discussed in 
the following sections. Figure III-5 shows how each of the hydrological 



28 - 



FIGURE III- 5 

HYDROLOGIC MODELS RELATING 
TO THE WADE MODEL 



Groundwater 
Flow Model 
(USGS) 



Groundwater 

Model 
(DWR-HEM) 



Water Use 
Survey 
(USGS) 



Seepage Study 
of Farm Ditches 
(Westlands WD) 




WADE 

HYDROLOGY 

MODEL 



Groundwater 

Model 
(DWR-HEM) 



Output Display and 

Interpretation using 

a CIS (SJVDP) 



'T) Input data files to the USGS and DWR groundwater models are used to obtain aquifer 
characteristic parameter values for the WADE model. 



, 1 Intensive data collection efforts to improve estimates of the hydrologic mass balance calculations for 
' water use and irrigation efficiency. 



Q 
Q 

Q 
G 



Modeling studies which focus on specific hydrologic phenomena that are treated in a more general 
fashion within the WADE model. Results of these investigations may indicate opportunities to 
modify the current model algonthms within WADE to improve predictive capability. 

Transient simulations run with the USGS and DWR models will be compared to simulation runs 
using the WADE model. For regions within the suidy boundaries where measured data are 
inadequate, the WADE model will be calibrated to the outputs from these models. 

Use of a geographic information system allows results of the WADE model runs to be presented 
graphically improving interpretation of these results. The CIS model output can be transformed 
From a polygon cell to a water district basis. 



- 29 - 



studies relates to the WADE model. Table III-l compares the characteristics 
of the various hydrologic models used by the Program. 

Ground-water flow model of the Panoche and Cantua Fan areas (USGS) 

Ground-water and salinity management model (J.M. Lord) 

Hydrologic-Economic Model (DWR) 

Broadview agricultural return flow model (URI, Broadview Water 

District) 
Water use survey of agricultural lands in the western San Joaquin 

Valley (USGS) 
Investigation of ground-water flow into subsurface drains (USGS) 
Potential use of ground-water pumping for water table management 

(SJVDP/Matanga/Schmidt) 
Seepage losses from on-farm distribution systems (Westlands/Boyle) 
Analysis using a Geographic Information System (SJVDP) 
Surface water network model for the Grasslands drainage basin 

(SJVDP) 
San Joaquin River model (SWRCB) 

Ground-Water Flow Model of the Panoche and Cantua Fan Areas . The USGS 
has constructed a model to study the effect of irrigated agriculture on the 
regional ground-water flow system and to explain the current area! 
distribution of the water table and the distribution of salts and selenium in 
the vicinity of the Panoche and Cantua alluvial fans. These areas contain 
some of the highest ground-water selenium levels in the western San Joaquin 
Valley. 

The USGS ground-water flow model considers five layers between the ground 
surface and the top of the Corcoran Clay and divides the study area into a 
I-mile grid, aligned parallel to the general direction of ground-water flow. 

- 30 - 



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- 31 - 



The current model runs a steady-state analysis and is the result of two years 
of intensive calibration and verification studies using both recent and 
historic well logs and aquifer pump tests. These studies have indicated that 
reductions in the rate of ground-water transmission across the Corcoran Clay 
due to increasing piezometric heads in the confined aquifer will lead to a 
faster rate of rise in shallow ground-water levels. A transient flow model of 
the regional aquifer in the study area is being constructed by the USGS to 
simulate water table elevations as affected by water conservation and drainage 
management practices. 

Aquifer hydraulic parameters from the steady-state analysis have been 
used to estimate vertical hydraulic flows between layers and lateral flows 
between polygon cells in the WADE model. Estimates of ground-water fluxes 
across the Corcoran Clay from the USGS model are also used in the WADE model. 
These estimates may be applicable to other areas with similar piezometric 
heads in the confined aquifer and where the Corcoran Clay is penetrated by a 
similar numbers of deep wells. Many of the wells that penetrate the Corcoran 
Clay permit significant leakage between the upper semi -confined and confined 
aquifers. Predicted water table elevations from simulation runs using the 
transient regional flow model will be used where appropriate to assist the 
calibration of the WADE model. 

Hydrologic-Economic Model . The Department of Water Resources (DWR) has 
developed an integrated Hydrologic-Economic Model (HEM) which evaluates the 
economic impact of ground-water overdraft in the San Joaquin Valley. The 
Drainage Program uses the calibrated HEM ground-water model to estimate the 
initial aquifer conditions assumed in the WADE model. These conditions 
include horizontal and vertical hydraulic conductivities, aquifer specific 
yield (unconf ined/semi-confined) , and boundary conditions. 

- 32 - 



The major differences between the HEM and the WADE model are the size of 
the polygon cells and the detail of simulated irrigation and drainage 
activities. The analysis units (cells) used in the HEM are based on 
institutional boundaries and are larger than those in WADE. HEM does not 
consider soil and ground-water salinity nor does it explicitly model 
agricultural drainage. A summary of the differences between the two models is 
shown in Table III-l on page 31. 

Ground-Water and Salinity Management Model . Irrigation scheduling 
information provided to valley farmers by agricultural advisors is generally 
based on available data for crops and daily evaporation rates. A Ground-Water 
and Salinity Management Model is being developed for the Drainage Program to 
combine irrigation scheduling and water application data with a drainage model 
that reflects root-zone salinity and estimates return flow quantity and 
quality from individual farm fields. 

The Drainage Program contracted with J.M. Lord, Inc. to develop the 
combination irrigation/drainage model (SWAP-ET/DRAINMOD) specifically to 
evaluate the effects of various water table management strategies on drainage 
flows and on the rate of salinity buildup in the root zone. The ground-water 
and salinity management model includes a weather-based irrigation scheduling 
program, SWAP-ET, to provide water application information to a water-balance 
model. The water balance model, DRAINMOD, originally developed for drainage 
in humid climates, has been modified to provide estimates of upward water 
flux, a phenomenon which occurs under arid conditions when the water table is 
within 4 feet of the soil surface. 

An intensive monitoring program is being conducted to calibrate the model 
for general use in the study area. The SWAP-ET/DRAINMOD model requires crop- 
specific information and climatic data available through DWR's California 

- 33 - 



Irrigation Management Information System program to develop daily 
evapotranspiration (ET) and potential evapotranspiration (ETp) estimates. 
DRAINMOD requires detailed soil information to calculate infiltration and 
seepage, upward flows of water into the root zone, and water table responses 
to irrigation applications. Root-zone salinity is estimated by using a system 
of equations which considers the movement of shallow ground water and salts 
between a number of layers in the root zone. 

This SWAP-ET/DRAINMOD model is being used to design and evaluate water- 
table management techniques that can reduce subsurface drainage flows while 
sustaining crop yields. Common drainage-control techniques include in-line 
weirs and flow control valves in subsurface drains. The ground-water and 
salinity management model provides the WADE model with the design 
specifications necessary to estimate drainage hardware and installation costs 
to more closely simulate average drainage system performance and cost in the 
study area. This model, which runs on a daily timeframe, produces accurate 
estimates of seasonal deep percolation losses and seasonal upward flow into 
the root zone from the ground-water table than can be obtained from WADE. In 
areas where there are sufficient drainage monitoring records to calibrate the 
model, it can be used to provide WADE with accurate estimates of seasonal salt 
fluxes into and out of the root zone. 

Broadview Agricultural Return Flow Model . To obtain detailed farm-level 
data for incorporation in the WADE model, the Drainage Program contracted with 
the University of Rhode Island to expand on an existing data collection 
program at Broadview Water District. The additional work included an economic 
analyses of grower management decisions affecting crop yields and soil 
salinity. This information was compared with drainage-related conditions 
which occurred prior to the availability of a District drainage outlet (1983). 

- 34 - 



The Broadview study also involved developing crop-specific agricultural 
production functions for the WADE model from areas with cropping patterns 
similar to Broadview's. 

Another task in the Broadview study involved examining the relationships 
between flows, loads, and concentrations of total salts, selenium, and boron 
in subsurface drainage. Findings from this part of the study showed that 
although linear load-flow relationships could be established for selenium, 
total dissolved solids, and drainage flows for individual sumps, the salt and 
selenium concentrations in these flows varied widely. The design of the 
drainage system, its age, and the aquifer layers that contribute to drain flow 
play major roles in determining the salt and selenium concentrations in the 
sumps. A methodology was developed for estimating the contribution of 
baseflow to total drainage flows over an irrigation season. Observed drainage 
flow and quality data from the Broadview study are being used in calibrating 
the WADE model . 

Water Use Survey of Agricultural Lands in Western San Joaquin Valley . 
The water use survey being conducted for the Drainage Program by the USGS 
involves compiling water delivery and well pumping records and estimating 
irrigation water use in the study area. This study serves several purposes 
which include providing water use data for both the WADE and USGS ground-water 
flow models, ensuring the quality of records in the data base for the study 
area, and establishing a public clearing house for water-use records. 

To date, cropping maps, water delivery records, and public utility power- 
use records have been integrated using a Geographic Information System to 
determine water applications on a 1-mile grid for the Grasslands Subarea and 
for much of the Westlands Water District. Current research by the USDA Water 
Management Laboratory; J.M. Lord, Inc. (previously described); and monitoring 

- 35 - 



programs by individual water districts provide information on the relationship 
between water application and ground-water recharge. Irrigation performance 
data collected from over 1,000 locations throughout the drainage service area 
by the DWR-SCS Mobile Labs have been summarized in the WADE polygon cells and 
will be used in further refining ground-water recharge estimates. 

Investigation of Ground-Water Flow into Subsurface Drains . Stratifica- 
tion of the regional ground-water aquifer, both in terms of soil texture and 
the concentration of salts and other chemical constituents, makes it difficult 
to establish general relationships between drainage flow and solute 
concentration. A two dimensional finite-difference study initiated by the 
USGS in 1987 uses isotopes to trace the origin of drainage water at several 
sites in the study area. USGS monitoring studies of the complex hydraulics of 
water movement into subsurface drains have shown that much of the water moving 
into the drains has been in the ground-water system for periods of up to 30 
years. These studies have also shown that drainage water concentrations of 
salts and trace elements are much higher for recently installed drainage 
systems than for systems five to ten years old. The elapsed time since drain 
installation and the travel time from the point of application to entry into 
the subsurface drains are both factors which determine the concentration and 
loads of salts and trace elements in drainage water. The lengths of the 
flowpaths into the drains are related to drain spacing and depth and dictate 
the strata of the shallow aquifer from which return flows are derived. Thus a 
knowledge of these flowpaths and the chemical stratification of the shallow 
ground-water aquifer can help to improve estimates of seasonal concentrations 
of salt, selenium, and other trace elements in drainage. 

Results of these studies and the Broadview studies indicate that drain 
sump concentrations of selenium and other trace elements vary more widely 

- 36 - 



between sites than they do over time at any one site. Since drainage water 
consists mainly of displaced ground water, the TDS and trace elements in 
drainage are more comparable to shallow ground-water concentrations than the 
concentrations in percolating irrigation recharge. The WADE model estimates 
the salinity of subsurface drainage water for each polygon cell and for each 
layer within a polygon cell by mass balance. Regression equations have been 
formulated between TDS and trace element concentrations for drainage return 
flows in polygon cells with installed subsurface drains. This allows the WADE 
model to estimate selenium and boron concentrations in drainage return flows 
based on the salt loads generated by each polygon cell. 

Potential Use of Ground-Water Pumping for Water Table Management . 

Ground-water pumping may be a cost effective means of controlling shallow 
ground-water tables for several areas in the western San Joaquin Valley which 
have poor quality shallow ground water (3,000 to 30,000 electroconductivity in 
millimhos per centimeter) which is underlain by relatively good quality water 
(1,500 to 2,500 electroconductivity in millimhos per centimeter). A study is 
being conducted for the Drainage Pr*ogram by G. Matanga and K. Schmidt to 
evaluate the technical feasibility of pumping from various levels in the 
semiconfined aquifer to control water levels. Ground-water flow and solute 
transport models are being used to simulate the effect of ground-water pumping 
on water-table response and the movement of salts in the semiconfined aquifer. 

The technical feasibility of water-table management through pumping has 
been demonstrated in field evaluations at a location in the Panoche Water 
District where rapid areal drawdowns were achieved during a 72-hour test. 
Long-term simulation of ground-water pumping strategies will help in 
evaluating the feasibility, cost, and environmental acceptability of this 
technology as a component of an overall management plan for salt and selenium 

- 37 - 



management in the western San Joaquin Valley. Ground-water pumping strategies 

and the resulting effects on the aquifer will be simulated by the WADE model. 

Costs associated with the pumping option will be included in the economic 
analysis. 

Seepage Losses from On-Farm Distribution Systems . Seepage can contribute 
significantly to shallow water tables and resulting ground-water problems. 
Annual seepage losses in Westlands Water District have been estimated to be as 
high as 100,000 acre-feet from on-farm canals, ditches, and reservoirs. 
Knowing the magnitude of seepage losses is important to both individual 
growers and district officials in assessing drainage reduction alternatives. 
Additionally, this information is used by the WADE model in characterizing the 
drainage reduction potential of the average farm area in each polygon cell. 

A study is being conducted by Westlands and Boyle Engineering to estimate 
seepage losses from on-farm distribution systems and to evaluate the net 
benefits of constructing alternative conveyance systems. Soil survey reports 
and field analysis are being used to classify the various soil types in the 
water district to identify relationships between seepage losses, soil texture, 
and drainage system construction techniques. The results of this study will 
be used in establishing seepage loss estimates for polygon cells in the WADE 
model . 

Analysis Using a Geographic Information System . A Geographic Information 
System (GIS) has been developed using ARC-INFO software to support ground- 
water modeling studies by providing a graphical means to inventory and analyze 
a wide range of data. The primary functions of a GIS are to automate, 
display, manipulate, and analyze spatially organized data as an aid to 
decisionmaking. 

- 38 - 



One prominent feature of the GIS is its ability to represent spatially 
aggregated data in several formats. This allows results of simulations 
produced by the WADE model to be presented for individual polygon cells, for 
water district areas, or for areas within other specific institutional, 
political, or topographical boundaries. During plan evaluation, output from 
simulation runs will be graphically displayed as overlay maps. The evaluation 
criteria will then be applied to evaluate the effects estimated by the model 
and produce a ranking of the management options that produce the maximum 
returns in terms of four accounts described in Chapter IV. 

Surface Water Network Model for the Grasslands Drainage Basin . The WADE 
model does not consider the surface water distribution system explicitly. 
Rather, it assumes that crop or wetland water needs within each polygon cell 
are fully met without constraints imposed by the delivery system. Algorithms 
have been formulated in the WADE model to distribute the water-use estimate 
for each polygon cell among beneficial use, deep percolation, surface runoff, 
and drainage for each polygon cell. 

The surface water conveyance system in the Grasslands drainage basin 
delivers fresh water to privately and publicly managed wetlands and some 
agricultural lands and accepts agricultural and wetland return flows through 
Mud and Salt Sloughs for discharge into the San Joaquin River. Tracking flow 
volumes and the concentration of salt, selenium, and other trace elements in 
these flows is very difficult in Grasslands because of the variety of wetland 
management practices, each of which takes and releases water on a different 
schedule. Flow volume and concentrations are also affected by the variability 
of drainage quality and quantity from upslope irrigation. As much as 15 per- 
cent of this drainage water is used as a water supply to lands within the 
Grasslands sub-basin in any one year. 

- 39 - 



The surface water network model will permit evaluation of various wetland 
management options including the conjunctive use of drainage water. The 
hydraulic and economic implications of these various options can then be 
incorporated into WADE. 

San Joaquin River Model (SWRCB) . An input/output model of the San 
Joaquin River developed by the State Water Resources Control Board in 1987 is 
being used by the Drainage Program to estimate the effect of TDS and trace- 
element concentrations in Mud and Salt sloughs on water quality in the river. 
The data base built into the model is for 1977-1985. However, selenium and 
molybdenum data are available only for 1984 and 1985. 

The river model will be operated with the surface water network model to 
determine how changes in wetland practices and reductions in the quantity and 
quality of agricultural drainage water moving through the Grasslands area 
affects the concentrations of salt, selenium, and trace elements in Mud and 
Salt Slough and the San Joaquin River. 

SAN JOAQUIN VALLEY AGRICULTURAL PRODUCTION MODEL 

The WADE San Joaquin Valley Agricultural Production Model simulates 
on-farm production decisions in response to changes in prices, costs, 
technological factors, and the institutional environment. The model assumes 
that growers make decisions to maximize profits. Based on this assumption, 
the model predicts cropping patterns, agricultural production and income, 
adoption of irrigation technologies, ground- and surface-water use, the amount 
and quality of deep percolation, and the reduction in tailwater and subsurface 
drainage associated with alternative management options. It can describe 
developments in farming conditions over a specific time period for alternative 



40 - 



option and scenario assumptions which can be varied to meet different 
objectives of those using the model. 

The production model requires data on fixed and variable costs for each 
crop (for example capital costs, labor, irrigation system maintenance, and 
other equipment costs), market prices, price elasticity, energy requirements 
for each irrigation technology, evapotranspiration and deep percolation by 
soil type, and crop and water application. 

A technique known as Positive Mathematical Programming (PMP) is used to 
overcome a fundamental difficulty in using linear programming models to 
portray regional production activities. The simplification required to keep a 
linear model manageable prevents it from performing realistic simulations. 
Local variations in costs and management practices are difficult to account 
for in these types of models, and thus they often fail to predict actual 
farmer behavior. Using PMP, the San Joaquin Valley Agricultural Production 
Model is calibrated to the observed grower responses for the years with 
recorded crop acreages. Thus PMP matches model results to observed 
conditions, taking into account social, institutional, and other factors not 
shown in a grower's crop budget. This approach results in more realistic 
projections and allows validation of the economic model similar to validation 
of hydrologic models. 

Economic Studies Supporting the WADE Model 

Two additional economic models are being developed to enhance the power 
and reliability of the WADE agricultural production model to simulate grower 
on-farm decisionmaking. Both models will be incorporated into the WADE model. 
The first is the Irrigation Technology Adoption/Diffusion model which will 
consider: (1) A variety of factors influencing grower decisions regarding 
adoption of irrigation technology, and (2) the effects of time on technology 

- 41 - 



diffusion. The second model, On-Farm Decisionmaking under Salinity 
Conditions, will enable an expanded WADE model to consider the effects of 
salinity on grower decisionmaking at the farm level. The WADE model currently 
treats each cell as a single grower unit. 

Irrigation Technology Adoption/Diffusion Model . As previously explained, 
a fundamental assumption of the WADE model is that growers will make decisions 
to maximize their profits, including irrigation technology choices and 
drainage installation decisions. Social and other non-economic factors such 
as grower knowledge, tradition, farm size, perceptions of soil salinity, risk 
aversion, and crop yield also appear to be important in the decisionmaking 
process. Changes in irrigation and drainage practices typically occur more 
slowly than profit maximization alone would predict. To help reconcile these 
differences, the Drainage Program is developing a model of technology adoption 
and diffusion behavior and plans to validate it with survey information 
collected from farm consultants and advisors during the summer of 1988. This 
model will be incorporated into WADE and will enable the model to make more 
realistic simulations of water table rise, drainage production, land use, and 
farm income. 

Qn-Farm Decisionmaking under Salinity Conditions Model . Knowledge of 
crop production functions (yield response to total water application) is 
critical in determining optimal cropping patterns in the agricultural 
production model and optimal irrigation technology in the Technology 
Adoption/Diffusion model. These production functions are developed by the On- 
Farm Decisionmaking model constructed by the University of Rhode Island. (The 
hydrologic aspects of this study were previously described.) The On-Farm 
Decision model is a micro-level that estimates yield response for various 

- 42 - 



irrigated crops and examines the economic impacts of salinity at the farm 
level. The model, which assumes that farmers maximize net revenues subject to 
constraints, develops a different production function for each irrigation 
technology and examines yield response to water application for that 
technology. 

Understanding the production functions for different crops at different 
salinity levels is fundamental for assessing the impacts of different policies 
regarding water and drainage charges or quantity limitations. These 
production functions will be used in the WADE model and improve the model's 
ability to optimize total farm income at different salinity levels and to 
compare changes in farm income with the cost of various actions to reduce 
sal inity problems. 

The model has been applied to the 10,000-acre Broadview Water District in 
Fresno County, which is representative of the high-selenium soil conditions 
derived from Panoche Fan alluvium. In applying this model to the Broadview 
Water District, production functions were developed for major crops for four 
time periods representing different soil salinity and drainage conditions. 
The model calculates changes in the production function between those periods. 

Broadview Water District, which is almost entirely surface-irrigated, has 
an adequate supply of good-quality water. Until 1983, however, the district 
did not have a drainage outlet, and thus had to recycle all subsurface 
drainage water. By the early 1980's, this recycled water accounted for about 
50% of applied water resulting in saline water application and salt buildup in 
the soil. As a result, high-value crops such as tomatoes and melons were 
replaced with lower-value salt-tolerant crops such as cotton and sugar beets. 

The four time periods referred to above included: 

1962-1970 (prior to the installation of subsurface drains) - 
Barley, cotton, and melons were the major crops. 

- 43 - 



1971-1976 (installation of drains and flushing of soils) - 
Tomato production peaked, cotton increased moderately. 

1977-1982 (recycling drainage and increasing salt buildup) - 
Dominated by cotton. Tomatoes dropped to nearly zero. 

1983-1986 (after installation of a drainage outlet in 1982) - 
As water quality improved, tomato and melon acreage was greatly 
increased and yields increased for all crops. 

Model parameters include crop acreages, yields, revenues, and total water 
application for each farm. Farm-level data were provided by the water 
district and field-specific data from the growers. Interviews with growers 
were designed to record their approach to on-farm water management, including 
their perceptions of the nature of their soils. This information will be used 
in identifying water management options and predicting grower response to 
these options. 

Currently, the production functions are formulated for water salinity 
levels during different time periods. Soil salinity and nutrients have been 
analyzed at the field level (20 samples per field) to correlate crop yields 
directly with in-field salinity level. When soil salinity is factored into 
the production function, it will be possible to plan optimal leaching 
strategies and thus minimize deep percolation. 

Other plans for the model include factoring soil texture into the 
production function in order to correlate the yields with various soil types. 

ADDITIONAL ECONOMIC ANALYSIS 

The Drainage Program is developing three additional models for economic 
analyses. One of these models addresses environmental values associated with 
drainage and related problems and potential solutions. A second examines the 
potential effects of management options (such as a drainage effluent charge) 

- 44 - 



on farm profitability. The third model addresses the economic analysis of 
potential health risks associated with agricultural drainage. Figure III-5 
shows how all of the economic models relate to the plan formulation and 
evaluation process. 

Economic Analysis of Environmental Impacts 

The environmental impacts associated with drainage and drainage-related 
problems and potential solutions will be assessed in terms of physical, 
biological, and economic effects on wildlife resources and habitats. The 
Drainage Program's approach to the economic analysis of environmental impacts 
proceeds in two phases: (1) Estimating the physical and biological effects of 
various options and alternative plans on fish and wildlife resources and 
habitats, and (2) economic valuation (monetary measurement of the benefits 
that society derives from the environment) of the estimated physical and 
biological effects. 

Current knowledge of the interrelationships between physical and 
biological factors and their effects on habitat is not advanced enough to 
permit formulation of mathematical models of ecosystem production functions. 
Consequently, assumptions concerning physical and biological relationships 
will rely heavily on professional judgment. Information generated by the WADE 
model such as farm drainage practices, levels of selenium and other 
constituents in drainage water, and quantities of drainage water will become 
input data which can be manipulated in terms of physical and biological 
relationships to produce estimates of environmental effects and the potential 
economic costs and benefits of these effects. Maps of these effects will be 
generated by the Geographic Information System to facilitate economic 
evaluation. 



45 - 



FIGURE III-6 

ECONOMIC ANALYSIS DIAGRAM 



AGRICULTURE 



ENVIRONMENT 



WADE Model 



Irrigation Technology 

Adoption / Diffusion 

Model 



On-Farm 

Decisionmaking 

Under 

Saline Conditions 



Estimate 

Physical / Biological 

Effects 



Improved 
WADE Model 



Farm Profitability 
Distribution Analysis 



Valuation 
Methods 



Ecosystem Values 



Health 

Risk 

Assessment 



Input to Plan Formulation 
and 
Evaluation Process 



- 46 - 



Environmental values are examined in terms of the public valuation of 
environmental amenities. This involves estimating the following values: 

Public recreation value which measures users' willingness to pay for 
recreation opportunities in the San Joaquin Valley such as hunting, 
fishing, and nature observation, 
Existence value which is the economic benefit society receives from 
simply knowing that environmental amenities in the valley continue 
to exist, now and in the future 
Option value which refers to public willingness to pay to assure the 
availability of environmental resources in the valley for their 
possible use in the future. 
The analysis of valley environmental amenities considers productive 
wildlife habitats, species that reside and/or rely on these habitats, and the 
potential effects on these amenities of various actions to resolve drainage 
problems. 

Figure III-6 shows two types of economic models used in analyzing San 
Joaquin Valley drainage problems: Agricultural economics and environmental 
economics. Methodologies have also been suggested to examine risk/benefit 
trade-offs and an approach to minimize costs associated with protecting public 
health. These models and methodologies are being used to help formulate, 
analyze, and evaluate alternative management options and plans. 

Monetary values will be estimated for three categories of San Joaquin 
Valley environmental resources previously described (recreational, option, and 
existence.) The methodology used to estimate these values is similar to a 
public opinion poll which asks people how much money they would be willing to 
pay to improve a resources or how much they would need to be paid to give up 
(or "sell") a resource. The first approach is known as "willingness-to-pay" 
and the second as "willingness-to-sell." Application of both methods has 

- 47 - 



shown that the "willingness-to-sell " approach typically results in higher 
values. Although the "willingness-to-pay" approach is more commonly accepted 
among economists, the Drainage Program will develop both for use in our 
analysis. 

Mitigation of environmental damages caused by agricultural drainage will 
be an integral part of solutions. In addition, any proposed enhancement of 
environmental resources above the base level will be evaluated in terms of 
benefits and costs prior to committing resources to such an effort. Economic 
valuation is important to help determine completeness and effectiveness of 
mitigation efforts. 

Farm Profitability Distribution Analysis 

An important consideration in setting drainage policy is the probable 
effect of higher drainage charges in terms of land-use changes, land going out 
of production, and the impact on employment and on local government revenue. 
The Farm Profitability Distribution Analysis addresses this question by 
defining the distribution of gross profitability (sales revenue less variable 
costs) associated with each crop. This analysis was originally performed by 
the State Water Resources Control Board Technical Committee. (An explanation 
of the methodology used and results of the analysis appear in Appendix G, 
Volume 1 of their 1987 report: "Regulation of Agricultural Drainage to the 
San Joaquin River. ") 

Using this analysis, the Technical Committee report projected that 
drainage charges up to $30/acre, would result in temporary insolvency for 
about 4% of the land. Only with drainage charges exceeding $30/acre was land 
projected to be permanently forced out of production. 

The farm profitability analysis is being expanded by the Drainage Program 
to a broader study area to investigate the financial impacts on grower 

- 48 - 



operations of cost increases associated with implementing alternative drainage 
management options. Using this profitability analysis in conjunction with the 
WADE model, the Program will examine both short-term economic impacts 
(financial distress and bankruptcy) and long-term impacts (land going 
permanently out of production). 

Economics of Health Risk Assessment 

Potential public health risks associated with agricultural drainage are 
being assessed in terms of five main drainage water constituents: selenium, 
molybdenum, boron, chromium, and arsenic. This involves several steps 
including determining maximum observed concentrations of these potentially 
toxic constituents, determining maximum safe concentrations, and identifying 
public health and environmental criteria for each constituent (established, 
proposed, or 1 ikely.) 

Research is also being conducted on potential routes of exposure such as 
direct inhalation, direct consumption of the water, and consumption of fish 
and wildlife with high bioconcentrations of the constituents of concern. This 
information will be incorporated in the Program's Health Risk Assessment Model 
which is based on a methodology developed by Lichtenberg and Zilberman (1987). 
This methodology can be used to assess the economic and social costs to 
control exposure routes and to maintain various standards for concentrations 
of the constituents of concern in the environment. Economic and social costs 
to assure protection of public health will then be assessed for each 
alternative plan. 

FINANCIAL ANALYSIS: PUBLIC/PRIVATE COST SHARING 

The Drainage Program is developing a methodology that will allow 
decisionmakers to evaluate the appropriate role for public cost sharing with 

- 49 - 



private parties for solutions to agricultural drainage and drainage-related 
problems in the San Joaquin Valley. Public participation in cost sharing 
would be based on benefits accruing to the public from implementing a 
solution. For example, given the national interest in migratory waterfowl and 
anadromous fishery resources, costs incurred to enhance these and other public 
environmental resources beyond levels associated with the mitigation of 
agricultural drainage-related damages may be proper candidates for sharing 
with the public at large. Likewise, the public would directly benefit from 
solutions which would lessen any risk to public health and protect the quality 
of surface- and ground-water resources for current and future beneficial uses. 

The public may also derive benefits from the preservation of soil quality 
for current and future uses which require relatively nonsaline soils, such as 
irrigated agriculture and wildlife habitat. Irrigated lands with poor 
drainage will likely require investments in a variety of technologies, such as 
improved irrigation practices and equipment, artificial drainage, drainage 
effluent treatment and/or disposal in order to maintain soil quality. The 
Drainage Program will use the dynamic portion of the WADE model to help 
estimate what level of investment in management practices and technologies 
private growers would be willing and able to undertake. This level of 
investment may be less than what is required to prevent salinization and 
maintain the long-term productivity of valley land. That part of the total 
costs exceeding the investment by growers may be appropriate for public cost 
sharing. 

Once the bases for public cost sharing have been established (that is, 
the direct public benefit now and in the future from enhancing environmental 
resources, reducing risk to public health, protecting water quality, and 
preserving soil quality), specific public and private beneficiaries can be 



50 



identified, alternative financing arrangements evaluated, and repayment 
provisions developed as appropriate to specific plans. 

REGIONAL ECONOMIC ANALYSIS 
Impact Analysis 

The regional economic impact of alternative plans for drainage management 
will be analyzed within the context of the Regional Economic Development 
account described in Chapter IV. Changes in regional economic activity are 
measured in terms of regional income and regional employment. Regional 
analysis will be conducted for areas with significant income and employment 
effects from a given plan, such as a particular subarea, valley-wide, or 
State-wide, as appropriate. (Impacts of plan implementation which occur 
outside the primary affected region are considered as national impacts 
affecting "the rest of the nation.") 

The positive and negative effects of a plan or strategy on regional 
employment are directly related to effects on regional income. To the extent 
practical, the analysis will include estimates of the composition of changed 
employment according to the relevant service, trade, and industrial sectors, 
including agriculture as a separate sector. The nature of the increases in 
employment will be identified for each sector in terms of required skill level 
where data are available. 

Input-Output Analysis 

Regional economic impacts resulting from plan implementation will be 
evaluated using input-output analysis. An input-output model of an economy 
describes the flows of goods and services among industries (sectors) and to 
final markets. Each industry requires a particular combination of inputs 
(such as materials and labor) to generate its output (goods and services) 

- 51 - 



which differ from sector to sector. The model can be used to analyze the 
implications of changes in one sector of the system, such as agriculture, on 
output, income, and employment throughout the rest of the economy depicted by 
the input-output model. This could be the local, regional, state, or national 
economy. 

A change in one sector of an economy can cause changes in several other 
sectors. For example, a decrease in agricultural production lowers the demand 
for such inputs as seed and fuel and also reduces production in industries 
which use agricultural products as their inputs, such as food processing. 
Additionally, production changes in each sector alter the income earned by its 
workers, which in turn may affect consumer spending and lead to changes in the 
production of consumer goods. 

Initially, changes in production, income, and employment associated with 
alternative management plans will be estimated using the interindustry 
relationship developed by the Department of Water Resources in Bulletin 210: 
"Measuring Economic Impacts, The Application of Input-Output Analysis to 
California Water Resources Problems." 

SOCIAL ANALYSIS 
Purpose and Objectives 

The Drainage Program is conducting analyses to identify social factors 
related to valley drainage problems and the plan formulation, evaluation, and 
implementation process. Social analysis contributes to the development of 
plans that are acceptable to the affected publics and feasible to implement. 
Analytical methods and data are being developed for the Program's social 
analysis to address the diverse issues associated with agricultural drainage 
in the valley both in terms of objective social outcomes and subjective social 



- 52 - 



meanings for individuals, organizations, and communities affected. In 
conjunction with other elements of the planning effort, the social analysis 
will : 

Identify and quantify social characteristics of the study area 

residents, organizations, and communities, 
Incorporate these data into the development, formulation, and 

evaluation of plans and implementation procedures, and 
Apply information about objective interests and subjective perceptions 
to assess the public acceptability and mitigation requirements for 
each plan option. This information will be used in developing the 
most effective, implementable, and acceptable plans. 
Alternative plans for solving drainage and drainage-related problems 
require a variety of actions to be taken by a diverse set of organizations and 
individuals. Consequently, the social analysis is focusing on the 
identification of key features of the valley social structures, delineation of 
the social and political processes which maintain or alter these structures, 
and incorporation of variables that influence the ability and willingness of 
key organizations and groups of individuals to take actions that contribute to 
the solution or management of drainage problems. Because of the shared 
objectives, social analysis interrelates with economic analyses and public 
involvement activities in the planning effort. 

General Approach 

A series of studies is being conducted by the Drainage Program to assess 
the effects of social variables on the ability and willingness of agricultural 
and wildlife habitat managers to take actions that would reduce drainage and 
related problems in the valley. The consequences of such actions on water 
management districts, farm operations, private habitat operations, and public 

- 53 - 



lands will be analyzed. Based on the outcome of this analysis, secondary 
effects on area local communities and other interested parties will be 
addressed. The general role of social assessment in the planning process is 
shown in Figure III-7. 

An analytic framework has been developed to guide priorities for data 
collection which is the first step in structuring social decision models. The 
principal criteria for evaluation are social well-being, implementabil ity, and 
public acceptability. 

Based on preliminary evaluation of existing data, the social analysis is 
focusing on the following areas: 

Compiling data that can be included in a Geographic Information System 
to analyze social factors affecting the ability and willingness of: 
(1) Water district staff, farm extension, and technical advisors to 
encourage and support the adoption of recommended water management 
techniques, and (2) operators and workers to adopt various on-farm 
water management options or comply with various water regulations, 
Compiling and analyzing information on social and organizational 
characteristics of local and regional water management agencies that 
affect implementation of alternative drainage management plans, 
Developing an information base to assess the impacts of various plan 
options on communities in the study area with respect to their social 
and economic viability, the quality of community and social services, 
and their ability to support the social well-being of residents, 
Preliminary investigation to determine the level of risk associated 
with any of the plan options as perceived by residents of the study 
area, and 



- 54 



Figure III - 7 

SOCIAL ANALYSIS DIAGRAM 



Define Problems 
and Objectives 



Identify Potential 
Alternative Actions 



Existing Social and 
Institutional Characteristics 



Potential Implementation 
Mechanisms and Procedures 



Identify Capacities/Roles/Authorities of Implementing Organizations 

Federal water and environmental agencies 

State water and environmental agencies 

Local and regional wter management (water, irrigation, drainage) districts 

Agricultural extension and technical assistance organizations' 



I 



Analyze Response to and Impacts of Alternative Actions 



Agricultural Operations 

Number and size of 

operations 
Number and characteristics 

of owners, operators, 

wortcers and thier families 
Ability and willingness to 

adopt recommended 

practices 
Acceptability of goals and 

methods of implementation 
Quality of farm life and 

work 



Private Wetland Habitat 

Operations 

(Primarily Duck Clubs) 

Number and size of operations 
Number and characteristics of 

owners, operators, 

shareholders 
Ability and willingness to 

adopt recommended 

practices 
Acceptability of goals and 

methods of 

implementation 
Quality of life 



I 



Public Wetland 
Habitat Operations 

Size and characteristics 

of operations 
Ability and willingness to 

adopt recommendated 

practices 
Acceptability of goals 

and methods of 

implementation 
Quality of life 



Local Communities 

Population size and characteristics 
Economic diversity and vitality 
Infrastructure (public and private) 
Acceptability of goals and 
methods of implementation 



I 



Other Stakeholders 

(Environmental and Special 

Interest Groups) 

Acceptability of goals and metliods 
of implementation 



I 



Feedback to Problem/Objective 

Identification and Alternative Actions 

(Iterative Process) 




- 55 - 



Review of existing surveys and polls to identify trends in public 
opinion concerning agriculture, environmental protection and 
enhancement, governmental regulation, and water management. 

Tools and Methods 

Data collection techniques include interviews with key informants, 
compilation and analysis of records (such as budgets, property ownership, and 
county and municipal annual reports) and sample surveys. Several studies have 
been conducted for the Drainage Program using these methods to characterize 
the communities of the valley. 

Existing surveys, polls, and other data are being identified which 
characterize current and historical attitudes of California residents towards 
agriculture, environmental protection and enhancement, governmental 
regulation, and water management. These data will be used to identify key 
values associated with particular issues and interest groups and, where 
sufficient data are available, to analyze trends. This information will be 
incorporated with other social, institutional, and public involvement data to 
help determine the social and political feasibility of plans. 

Social data will be mapped and integrated into the Geographic Information 
System used by the Program as appropriate. This information can be used to 
identify people who share common interests and thus form the basis of 
solidarity groups or coalitions to support the adoption and implementation of 
particular plans. The data will also assist in identifying potential 
conflicts within and between organizations so that the basis of the conflict 
can be addressed. 



55 - 



Use of Social Analysis 

The data and models being developed in the social analysis will be 
expanded and used in successive stages of the planning process. For example: 
Analysis of the organization and administration of water management 
districts, agricultural extension, and technical assistance 
organizations in the study area is used to characterize the mode of 
operation of these organizations and to assess the feasibility of 
proposed actions, assist in forecasting the extent and timing of 
response to incentives and recommendations, and identify problems that 
might affect plan implementation. 
Current and historical data on private fish and wildlife habitat and 
agricultural operations in the Grasslands and Westlands areas are used 
in identifying potential implementation mechanisms and procedures and 
in evaluating the consequences of plan options and implementation 
strategies. 
Descriptive information on community infrastructure and employment 
patterns in the San Joaquin Valley provides baseline measurements for 
comparing projected impacts of alternative plans and for evaluating 
the degree of change projected over the planning period compared to 
recent trends. 
Resource use patterns in the study are utilized in identifying the 
distribution of potential risks and benefits of different plans and 
assessing implementabil ity and acceptability. 
The study of farm operations and the relationship between farm 
characteristics and community conditions is used in identifying 
factors affecting the adoption of various agricultural technologies, 
the acceptability and implementabil ity of water conservation plans and 



- 57 - 



changes in land use and farm income, and the consequences of 
implementation on farm operations and community conditions. 

INSTITUTIONAL ANALYSIS 

Certain types of institutional changes could play an important role in 
solving the agricultural drainage and related problems of the valley. 
Research is underway to identify and assess the effect of pertinent laws, 
policies, and institutional arrangements to determine what institutional 
changes could contribute to potential solutions. 

Overview of Institutional Setting 

The first phase of the analysis will be to prepare an overview of Federal 
and State regulations, policies, laws, and institutional practices related to 
water rights, irrigation and drainage management, environmental protection, 
fish and wildlife resources, and public health. The overview will include 
information on Federal reclamation law related to restrictions and potential 
opportunities for water marketing. It will examine the rules, regulations, 
and policies of the Bureau of Reclamation regarding water transfers by 
contractors, repayment policies, rate setting and adjustments, and water 
conservation incentives and measures. 

The institutional overview will also include an analysis of California 
constitutional and statutory law governing the acquisition and transfer of 
water rights, reasonable and beneficial use requirements, water conservation, 
the public trust qualification on water rights, conjunctive use of ground and 
surface water, ground-water rights and regulations, water user liability for 
adverse environmental impacts, and rights to return flows including those from 
irrigation and wetland areas. State laws governing the establishment and 
operation of the State Water Project and water distribution districts will be 

- 58 - 



analyzed with respect to their decisionmaking structures and the constraints 
these laws may impose upon water pricing mechanisms, water reallocations, 
wheeling, and other contractual arrangements. Comparative information will be 
collected and analyzed on the legal authorities, administrative powers, and 
financial structures of California's water districts and a description of 
standard features of typical contracts executed by these districts. 

The framework within which the State Water Resources Control Board 
operates will be analyzed. This will include the Board's authorities and 
responsibilities related to changes in point and period of diversion, changes 
in amount of water use or place of use, transfer of water rights for temporary 
use, and water conservation measures. The authorities and responsibilities 
the State Water Resources Control Board, associated Regional Water Quality 
Control Boards, and the U.S. Environmental Protection Agency related to 
establishing and maintaining water quality standards and/or basin plan 
objectives to protect beneficial uses of surface, ground and drainage water 
will also be examined. 

Relationship to Drainage Problems and Issues 

The issues, constraints, and opportunities identified in the overview 
phase will be analyzed to determine how they apply to the range of management 
options and alternative plans being developed by the Drainage Program. The 
output of this analysis will be a list of key constraints that would have to 
be overcome in implementing plans, and opportunities that could be used within 
the context of alternative drainage management plans. Necessary steps will be 
described to remove obstacles or take advantage of opportunities. Examples of 
removing obstacles, for example, could include legislative or Congressional 
amendments, changes in agency rules, reinterpretations of statutory 



59 



authorities, resolution of pending lawsuits, petitions for changes in by-laws, 
and reformation of contracts. 

Implementing Change 

Where the Drainage Program identifies constraints and possible reform 
measures, a detailed investigation will be conducted to determine the 
likelihood of implementing the institutional change. This will include 
research regarding the history of efforts to effect these or similar changes 
in the appropriate forum. The likely chain of events required for successful 
implementation of removal of constraints or reform measures will be conducted. 
The final task will be to prepare analyses and justifications for implementing 
recommended institutional changes within the context of solutions developed by 
the Program. 



60 



CHAPTER IV 
PLANNING PROCESS 



This chapter discusses the 
planning process and illustrates 
the analytical procedures and 
evaluation criteria being used in 
formulating and evaluating 
alternative plans to solve drainage 
and drainage-related problems in 
the San Joaquin Valley. Plan 
formulation and evaluation involves 
six basic steps, shown in 
Figure IV-1: (1) Identify drainage 
and drainage-related problems (both 



1 



Idenlifv Drainage 
and UrainaRe- 
Kelated Problems 



PLANNING PROCESS 



Improve Dau Base 

SsHiixe, Mofaiiuy. and 

Avail- of TiJce Eletnooa 
Ground- Water H^fltotoOf 
G«og. Extern, Nacurt. uiJ 

S«vemy ol Conuroio*mj 
Taxtc Effeco af Tt3« 

£ko>«oa an FbJi 

and Wildbfe 
Pcneou«] RJiki to 

Public Health 
Xmcaooo *nd Drainage 

Mpnt. T«cftnoJocf 
Dnmage Wxet Treaor^m 



Idcniirv Poleniial 
ManaecmenI OpUons 
and LTfecis 

InMiiuiionjI Change} 
Source Comrol 
Drainage Tceaimeni 
Drainage Reuse 
Drainage Di&poial 
Fi^h and Wildhle 
Managcmeni 



Apply Evaluaiion Crileria 

Ellectiveness 
Economic Ellicicnc* 
Com AUocaiion/Sharing 
Rjsk A^eumeni 
Environmental Petlormance 
In^utuiional Fea^ibUity 
Social Ellecu 

Itfevenible'ltfeirievable Elfecis 
Unavoidable Ad-.ef5e EUecis 



Devdop AnolyUcal 
Model* A Proctduree 



Hvdn>(< 'gicjl AoaJvTO 
AciicuLiural PtoducUvitT 
f\sh aod 'A'Udbte Rejoutccs 
Health Ritk A,v'*6Ain?nt 
Etnaocial AnilVTii 
Reoonul Enjuomio 
Soual f jaon 
Instnuuooal Analyst 




FIGURE IV-1 - Formulating and Evaluating 
Plans. This chapter discusses the 
procedures and criteria being used in 
formulating and evaluating management 
options and alternative plans. 



current and projected future conditions without a coordinated, comprehensive 
plan), (2) identify and estimate effects of potential management options, 
(3) evaluate options, (4) formulate and estimate effects of alternative plans 
(combinations of options) for each of five planning subareas, (5) evaluate 
plans, and (6) recommend plan(s). This chapter addresses steps 1 through 5. 
The process is iterative, and steps 4 and 5 will be repeated, as necessary, to 
further refine plans in light of new information and knowledge related to plan 
effects. 

The process is adapted from the one recommended in the Federal and 
Environmental Principles and Guidelines for Water and Related Land Resources 
Implementation Studies (Principles and Guidelines). The Principles and 
Guidelines are intended to ensure proper and consistent planning by Federal 



- 61 - 



agencies in the formulation and evaluation of water and related land resources 
implementation studies. 

PROBLEM IDENTIFICATION AND PROGRAM PURPOSES AND GOALS 

The purposes of the San Joaquin Valley Drainage Program are to 
investigate valley drainage and drainage-related problems, to identify 
measures to help solve immediate problems, and to develop comprehensive plans 
for long-term management. Four principal types of problems have been 
identified related to the management of valley agricultural drainage: 

(1) Potential public health risks that may be associated with certain trace 
elements such as selenium found in agricultural drainage water, 

(2) degradation of the quality of surface- and ground-water resources by 
agricultural drainage which impairs beneficial uses, (3) loss of fish and 
wildlife resources and related habitats caused by trace elements such as 
selenium and salt in agricultural drainage, and (4) reduction in agricultural 
productivity caused by rising, saline water tables which impair crop growth. 

Consistent with the Program purposes and the problems as identified, the 
Drainage Program has developed the following goals to be achieved to the 
maximum extent practicable: 

Minimize potential health risks that may be associated with subsurface 

agricultural drainage water. 
Protect existing and future reasonable and beneficial uses of surface 

and ground water from impacts associated with subsurface agricultural 

drainage water. 
Protect, restore, and enhance valley fish and wildlife resources. 
Sustain productivity of farmlands in the principal study area. 



52 



Present Conditions 

A detailed description of existing conditions within each of the five 
subareas comprising the Program's study area will be developed in measurable 
terms to the extent practicable. Some of the parameters to be used in the 
description include: available quantity and quality of water supply for 
agricultural and wetland uses; land use; types of vegetation; land and water 
management practices; quantity and quality of agricultural drainage; drainage 
water management practices; and others, as appropriate. 

Future-without Coordinated and Comprehensive Action 

"Future-without" conditions are those that would be expected to occur in 
the absence of coordinated and comprehensive action by Federal -State-local 
entities for managing valley agricultural drainage and drainage-related 
problems. Federal, State, and local agencies with water and drainage 
management responsibilities and the private sector are assumed to continue 
dealing with drainage-related problems, but on an individual basis that may 
not lead to efficient, long-term, regional solutions. 

While more than one set of possible future-without conditions, or 
scenarios, are possible, the most likely scenario provides a baseline for 
comparison and evaluation of the economic, environmental, and social effects 
of alternative plans formulated to solve problems as a coordinated, 
comprehensive effort. Figure IV-2 suggests how a range in benefits "with" and 
"without" coordinated comprehensive plans would be expected to vary over time. 
The increment shown as the vertical interval between lines represents the 
likely effects (which may be measured in acres of land in agricultural or 
wetland production, volume of drainage, grower profits, etc.) of implementing 
a plan. The estimated effects (from "without" to "with") can then be compared 

among alternative plans. 

- 63 - 



CO 

o 

< 

I 
CO 

o 



n 
I 



■O 77 






in 

o 

LL 
CO 



(0 

o 

<A 

I 
<V 

E 
o 
u 

c 



UL 
9 

z 



e 

CO 


c 







IC" 



imiim 



effe< 



l^'^/^oof Coorc/maf 



e</ Comprehensi 



•^e Actions 



1988 



199S 

Time Period 



2010 



FIGURE IV-2 CONCEPTUAL FRAMEWORK FOR 
COMPARING EFFECTS OF ACTION 



One difficulty in projecting future conditions is assuring that the 
future-without scenario is not overly influenced by a particular disciplinary 
bias or special interest. To help assure a balanced perspective, the Drainage 
Program invited representatives from Federal and State agencies, water 
districts, and public and private interest groups to participate in workshops 
designed to gather information for developing likely future-without scenarios. 

Table IV-1 lists nine factors identified as most likely to be considered 
by agricultural and wetland managers in dealing with drainage problems. 
Workshop participants then identified the assumptions associated with each 
factor which had a 50 percent or higher likelihood of occurring. The scenario 

- 64 - 



Factors 

Water 
supply 



Water 
conservation 



Table IV- 1 
Forecasted Future-Uithout Conditions 

Assumed Conditions - Year 2010^ 

The USSR will not be able to market uncommitted CVP yield for use on agricultural lands in the San 
Joaquin Valley due to controversy over water allocation, agricultural -related contamination, etc. 

Private wildlife (wetland) habitat owners will continue to purchase some CVP water at a nominal fee to 
satisfy a portion of the water needs for optimum management (Federal Government will subsidize the price 
of water for wetland use). 

The SWRCB will reallocate some CVP water rights for San Joaquin River instream uses (water quality and 
fish flows) and wildlife values on public wetlands. 

Water conservation measures and modified land use on the west side of the San Joaquin Valley, instituted 
by the agricultural community, will result in sufficient water savings by 2010 to allow replacement of 
the contaminated drainage water used for wetland management prior to 1985 without a significant increase 
in diversions from the Delta. 

Wetlands offstream water storage (for release during the April -May period to supplement San Joaquin River 
flows) will be continued subject to water availability. 

Federal CVP water delivery costs will increase sufficiently to cover the associated capital and 
operations and maintenance costs. 

Rights to unappropriated winter and early spring San Joaquin River flood or freshet flows above Mendota 
Dam will be appropriated for use in the study area. 

An integrated agriculture and wetland water supply system will be adopted, resulting in an overall 
increased water supply for wetlands. 

On-farm water conservation measures will be adopted in areas of high water tables resulting in 
significant reduction in present subsurface drainage volume. 

Conservation measures will also be adopted on upslope lands as a result of new pricing structures plus 
other incentives. The conservation measures will result in approximately 30% reduction in deep 
percolation in the study area by 2010. 

Tiered water pricing systems will be adopted by water districts with correlative State and Federal policy 
modifications. 



Public The public will approve a bond issue or general revenue expenditure for purchase, in fee or easement, of 
support currently irrigated farmland for conversion to wetland habitat. 

Foreign Trade barriers for selected crops will be imposed by the U.S. and the value of the dollar will continue 
trade to be low in relation to foreign currency, which will result in an improved overseas market for U.S. 
agricultural products. 

Public Key trading nations will have different health standards regarding pesticide/chemical treatment of 
health imported crops. The U.S. will place greater restrictions (e.g., on pesticide residues) on imported 
agricultural products. 

Federal or State public and environmental health standards will be established for all major agriculture- 
related chemical compounds. 

Farm subsidy The Nation's crop commodity subsidies will be reduced significantly for the major crops grown on the west 
side of the San Joaquin Valley (e.g., cotton, sugar beets, and wheat). 

Water Water districts will be given regulatory control over some aspects of individual farm irrigation and 
districts drainage water management districts and will be declared the legal action unit for compliance with water- 
quality (drainage) regulations. 

Water districts will become responsible for total water management, including drainage treatment and 
disposal facilities. 

Districts will become more active, better funded, and technically equipped in advancing water 
conservation and managing facilities to treat and dispose of drainage discharges. 

Existing restrictions on water management including water trading and resale will be reduced, allowing 
local districts and farm managers to make economically optimal decisions relative to water use. 



- 65 - 



Factors 

Drainage 
treatment & 
disposal 



Water-qual ity 
standards 



Assumed Conditions - Year 2010 ^ ] 

Farmers will pay the cost of drainage treatment and disposal. This will result in significant reductlci 
in drainage discharge beyond farm boundaries. ' 

No decision will be made on valleywide treatment and/or disposal of drainage water. 

Evaporation ponds will be permitted for disposal of trace-element-contaminated drainage water. Katz Bi 
standards and wildlife protection measures will be enforced. 

The San Joaquin River selenium standard will be 5 ppb (instream) and 2 ppb or better for wildlife habit 
water supply. 

San Joaquin River salinity objective will be 500 ppin IDS at Vernalis only. 

The San Joaquin River boron and molybdenum standard at Newman will be 1,000 ppb and 10 ppb, respective!] 

Wetlands will have to meet instream water-qyal ity standards. 

Agricultural drainage will be defined as a point source discharge and thus subject to all appropriate 
provisions of the Federal Clean Hater Act, as amended. 



This is the high-likelihood scenario presented in a Program report entitled "Developing Alternative Futur^-Without- 
Project Scenarios for Agricultural Lands and Wetlands in the San Joaquin Valley" with some supplemental material 
added as necessary to fully describe the factors. (Developed in a workshop with representatives of Federal and 
State fish and wildlife agencies, water districts, and Program staff members.) 



- 66 - 



presented in Table IV-1 reflects a 1990-2010 timeframe. In addition to the 
assumptions developed in the workshop, other assumptions were added as 
appropriate to more fully describe the factor and the scenario. 

For purposes of illustrating the analytical procedures, future conditions 
forecasted to differ from prevailing conditions were limited to two events 
with a high likelihood of occurring: (1) The adoption of water-quality 
objectives proposed by the Central Valley Regional Water Quality Control Board 
for the San Joaquin River near the town of Newman and Salt and Mud Sloughs, 
and (2) price increases for Federally supplied irrigation water based on 
provisions of the Reclamation Reform Act. A detailed description of future 
conditions for each of these factors will be presented in the Program's 
Alternative Plans Report to be completed later this year. The impacts of any 
proposed coordinated and comprehensive drainage management plan will be 
estimated by comparing the effects of the future-without conditions with those 
of the alternative plans. 

IDENTIFICATION OF MANAGEMENT OPTIONS AND ESTIMATION OF EFFECTS 

To date, approximately 60 management options have been identified as 
potentially helpful in solving existing and projected agricultural drainage 
and drainage-related problems in the San Joaquin Valley. These options are 
identified and briefly described in Table IV-2 for purposes of analysis and 
evaluation. The effects of the options will be estimated using the analytical 
procedures discussed in Chapter III and professional judgment. 

Because of the high degree of uncertainty related to the technical and 
economic feasibility of high-technology options (particularly treatment and 
deep-well injection), the planning process is currently concentrating on 
nonstructural management options. Table IV-3 identifies Program technical 
reports which provide quantitative information on several of these options. 

- 67 - 



Options 

INSTITUTIONAL CHANGES 

Renegotiate CVP 
Water Supply 
Contracts 

Increase Price 
of Water to 
Individual 
Growers 



Table IV-2 
Alternative Nanageaent Options 

Description/Rationale 



Increase rates for CVP irrigation water contracts with the specific intent to promote further 
water conservation and reduce drainage. (Anticipate CVP water contract negotiations at 
conclusion of existing contract period.) 

Significantly increase the price of CVP and SWP water (surcharge) to encourage less water 
application and thereby reduce drainage. 



Modify/Eliminate Reduce or eliminate the subsidy element in the pricing of project irrigation water. This 

Federal/State would lead to increased price of water for the consumer and a resulting increase in water 

Irrigation conservation, thereby reducing drainage. 
Subsidies 

Modify CVP & Change water marketing policies to allow water districts to pay for water actually used or 
SWP Repayment "bank" annual surplus repayment against next year's obligation. This would create an 
Policy to Allow incentive for increased water conservation and thereby reduce drainage. 
Payment Only For 
Water Used 

Tiered Water Increase the cost of water as specific volumes above a base level are exceeded to provide 
Pricing at Water an incentive for increased water conservation. 
District, CVP, 
or SWP Levels 



Water Marketing/ Encourage active marketing and trading of existing CVP and SWP irrigation water to 
Trading Policy potentially increased value for irrigation water and encourage water conservation. 



create 



Allocate CVP i 
SWP Water to 
Wetlands with 
Subsidy 

CVP & SWP Water 
to Wetlands 
Before Use for 
Agriculture 



Provide increased water supply to wetlands at low (subsidized) rate to increase and/or 
improve wildlife habitat. 



Use water first for wetlands and instream fishery prior to delivery for irrigated 
agriculture. (This would be accomplished either through rediversion of project water from 
the Sacramento-San Joaquin Delta or by constructing required facilities to recycle return 
flows into existing water supply systems.) This would improve the quality of water now 
available for fish and wildlife habitat. 



Reallocate Reallocate a portion of current SWP and CVP irrigation supplies for environmental uses 

Water from including instream flow and wetland management. This could both improve fish and wildlife 

Agriculture to habitat and encourage water conservation on irrigated agricultural land. 
Fish & Wildlife 



Reauthorize CVP 
and SWP to 
include Fish & 
Wildlife and 
Other Purposes 

Use CVP & SWP 
Water for 
Dilution of 
Ag Drainage 

Impose Drainage 
Effluent Fee 

Limit Drainage 
Effluent 



Change authorizations of water projects to emphasize equal consideration for allocating 
water supplies to fish and wildlife and related purposes. This would increase and/or 
improve habitat and could reduce irrigation supplies and agricultural 
drainage. 

Use water currently delivered for irrigation to dilute drainage discharge to the San Joaquin 
River to encourage increased conservation, achieve water-quality objectives, and facilitate 
drainage disposal . 

Require individual drainers to pay a fee based on amount and quality of drainage effluent 
generated and the cost of drainage management facilities to encourage conservation. 

Constrain the amount of drainage discharged from individual farms, districts, or regions 
(SWRCB waste-load allocation process). Internalize the cost of drainage produced by 
restricting the amount a unit is allowed to export. 



Tax Rebate Based Provide growers with a tax rebate based on their success in reducing deep percolation of 

on Total Water irrigation water. This would create an incentive to reduce deep percolation and drainage 

Mgmt Efficiency production. 

Alter Tax Change tax structures/rates for expenditures on irrigation and drainage management systems 

Structures & designed to conserve water. This would create an incentive to reduce deep percolation and 

Rates drainage production. 



- 68 - 



Options 

SOURCE CONTROL 

Water Conservation 

Del iver Water 
on Demand 



Line Canals/ 
Ditches/Ponds 



Increase Use 
of Irrigation 
Schedul ing 
Information 



Description/Rationale 



Provide irrigation water to growers and wetland managers on demand. Present conveyance 
restrictions may limit the quantity and/or timing of water deliveries, which reduces 
production and/or results in excessive water application in anticipation that sufficient 
water will not be available at the exact time of need. 

Line distribution canals, ditches, and ponds to reduce water loss/deep percolation. 
Water loss in existing unlined facilities contribute to shallow ground-water 
reservoirs and drainage problems. 

Increase efficiency of irrigation water application by growers use of irrigation scheduling 
information. Applying irrigation water at the proper time and in sufficient amounts to 
bring soil moisture to field capacity without excess deep percolation can minimize drainage 
volume. 



Modify/Change Change to more efficient methods of irrigation water application to reduce drainage volumes. 

Irr. Methods-- Using irrigation method best suited to soil texture, uniformity, slope, tngmt. experience. 

Surface, Drip, etc., helps ensure the optimal uniformity of applied water and minimize deep percolation. 
Sprinkler, etc. 

Improve Use existing irrigation methods and schedule irrigations to reduce deep percolation and 

Irrigation ensure a high uniformity of applied water. Combine available water supply information 

Water Mgmt on crop water demand with the optimal use of existing irrigation method to eliminate soil 
moisture depletion and minimize deep percolation. 

Change Farming Improve uniformity of water infiltration to reduce deep percolation. Soil permeability 

Tillage depends on soil texture and salinity, surface conditions, existence of shallow barriers. 

Practices etc., and tillage (both surface and deep) will assist in managing infiltration rates. 



Drainage Management 

Recycle Surface 
Drainage 



Collect and reuse surface water drainage from irrigated fields. The overall water-use 
efficiency can be improved; thus, ultimate drainage volume will be reduced and applied 
chemicals will be recycled. 



Reuse Subsurface Collect and blend subsurface drainage water with freshwater or surface runoff for 

Drainage with irrigation reuse. The overall water-use efficiency can be improved. In some instances, the 

Reuse Subsurface Use subsurface drainwater on salt-tolerant crops. The overall water-use efficiency will be 

Drainage without improved without the degradation of existing freshwater supply. 

Blending 

Ground-Water Pump good-quality water from below degraded zone to lower the water table. Conjunctive use 

Pumping to Lower of ground water may help maintain the shallow water levels below the crop root zone without 

Shallow Water the use of a subsurface drainage system. 
Table 

Reduce Drain Reduce the depth from which drainage water is drawn by decreasing drain spacing. The water 

System Spacing drained will be influenced less by the highly degraded ground-water zone, which is located 
below 20- foot depth. 

Manage Water Regulate shallow water-table elevation so crop roots can use water directly from ground 

Table to Satisfy water. The overall water-use efficiency will increase by the reduction of deep 

Portion of ET percolation, and the drainage yield can be managed to correspond with the optimal disposal 
rate. 



Separate 
Subsurface & 
Surface Drainage 



Crop Management 

Cultivate Crops 
Tolerant of 
Salt, High 
Ground Water, 
Drought, etc. 

Cultivate Crops 
Grown without 
Irrigation 

Incorporate 
Agroforestry 
in Cropping 
Pattern 



Provide separate collection and redistribution systems at farm and/or district levels for 
surface and subsurface drainage. The overall water-use efficiency will increase by 
reintroduction of surface drainage into the water supply system and, where feasible, reuse 
of subsurface drainage on salt-tolerant crops which can minimize the volume of drainage to 
be treated. 

Cultivate crops that produce yield under various stress conditions including water shortage, 
limited root zone, and soil salinity to increase the potential for sustainable agri- 
ture. Increase the flexibility of managing subsurface drainage by reducing the volume 
discharge for a drained field when environmental conditions are not favorable for disposal 
disposal of drainage and extend the time when a disposal system must be provided. 

Cultivate crops that produce yield without irrigation and with or without available water 
supply to roots from shallow ground water. Reduce existing drainage management problems by 
isolating contaminants in soil and shallow ground water. 

Irrigate tree stands with subsurface drainage water to reduce drainage water volume and 
produce wood products and an energy source. Reduce the size of disposal systems, especially 
evaporation ponds, while producing a marketable agricultural crop. 

- 69 - 



Options Description/Rationale 

Incorporate Grow crops that accumulate Se in Se "hot spots" and export crops to Se-deficient areas. 

Crops that Reduce the Se in soils and drainage while producing a high value crop for use in 

Accumulate Se Se-deficient areas. 



Alternate Land Use 

Cease Irriga- 
tion of Lands 
with High Con- 
taminant Loads 

Convert Irriga- 
ted Ag Land to 
Upland Habitat 



Convert Ag Land 

to Wetland 
Habitat 



Isolate contaminants in soil and shallow ground water by ceasing irrigation of lands with 
high contaminant loads. 



Allow agricultural land to revert to native grass typical for this area and/or introduce 
plants selected for specific wildlife species. Reduce existing agricultural drainage 
management problems by isolating Se in soils and shallow ground water below the root zone 
and achieve wildlife objectives. 

Reclaim land with suitable terrain and soils as wetlands. Reduce existing agricultural 
drainage management problems by isolating Se in soils and shallow ground water below 
the root zone while achieving wildlife objectives. 



DRAINAGE TREATMENT 

Biological 

Anaerobic- 
Bacterial 
Process 

Facultative 

Bacterial 

System 

Hicroalgal - 

Bacterial 

Process 

In-Situ Volati- 
1 ization of Se, 

In-Situ Volati- 
1 ization of Se, 
Soil II Sediment 

In-Situ Immobi- 
1 ization of Se 
in Aquatic 
Systems 

Chemical/Physical 

In-Situ Attenu- 
ation of Se in 
Soil Systems 

Iron Filing 
Process 

Ferrous 

Hydroxide 

Process 

Selective Ion- 
Exchange Process 

Reverse-Osmosis 
Process 

Cogeneration 
Process 



Remove Se from agricultural drainage by anaerobic-bacterial concentration of Se in a sludge 
blanket reactor with a sludge disposal process. 

Use facultative bacteria for reduction of Se. Similar process to anaerobic-bacterial 
process except it does not require an enclosed facility and thus can be effective in open 
ponds. 

Produce algal -bacterial biomass in high-rate algal ponds for methane generation in anaerobic 
digester. Methane is then used as an energy source for Se reduction with precipitant (Se 
plus other trace elements) removed for disposal. 

Volatilize methylated Se from aquatic systems by the addition of organic energy source for 
bacterial growth. {This process may be adaptable for use in evaporation ponds.) 

Volatilize methylated Se by the addition of organic sources to moist soils. 



Immobilize Se by maintaining reduced conditions in the upper layers of pond-bottom sediments, 
thus controlling Se migration. 



Reduce Se in soil systems by the addition of chemicals directly to soil, which results in 
volatil ization of Se. 

Adsorb Se onto iron filings for disposal of both filings and the adsorbed Se. 

Use ferrous hydroxide as a reducing agent to remove Se from drainage with the precipitants/ 
sludge removed for final disposal. 

Use selective ion-exchange resins to adsorb Se with backflushing and disposal of 
Se-concentrated sludge. 

Separate dissolved salts, including trace elements, from the drainage water by use of 
RO membrane. 

Generate electrical power using natural gas and/or agricultural wastes with the use of 
bypass heat to desalinate drainage water. 



REUSE 



Powerplant Use drainage water to cool fossil -fueled power generation plants and/or as an influent to 
Coolant/ a desal inization process, thus reducing the volume of drainage and cost of disposal. 
Desal inization 



- 70 - 



Options 



Description/Rationale 



Irrigation of Irrigate salt-tolerant crops (such as cotton and eucalyptus trees) with saline drainage 
Salt-Tolerant without freshwater dilution. (Freshwater is required to establish plants and subsurface 
Crops drainage systems.) This will reduce the volume of drainage and offset the cost of drainage 

management. 

Streamflow Use low salinity and contaminant level drainage for augmentation of streamflows. This would 
Augmentation increase the use of water and reduce drainage volume and the cost of drainage disposal. 

Aquaculture Use drainage water with low contaminant levels to culture a wide variety of organisms varying 
from algae to fish. 

Salt Harvesting Recover and market salts and minerals in drainage water to help defray costs of drainage 
solutions. This would also reduce volume of salts requiring, disposal . 

Solar Ponds Use concentrated brines from drainage water in nonconvective solar-gradient ponds to produce 
thermal or electrical energy, thus treating saline drainage as a resource and reducing the 
overall cost of drainage management. 



DISPOSAL 

Evap Ponds 
(Regional ) 

Containment of 
Salts on 
Individual 
Farms (Ponds) 

Deep-Well 
Injection 

Excavation & 
Containment of 
Contaminated Soils 

San Joaquin 

River 

Discharge 



Operate evap ponds at minimum of 3-foot depth and minimum of 3 cells lined (as necessary) to 
prevent degradation of underlying ground water. 

Reuse saline subsurface drainage for Irrigation of salt-tolerant crops (including trees) and 
evap/solar ponds and cogeneration electrical energy generation system. (See previous 
discussions for more details.) 

Inject drainage water into deep geologic formations to contain the water indefinitely. 

Dispose of drainage-water-contaminated materials by burial in a containment area. 



Release drainage with a controlled salt load (accomplished through treatment and/or 
Irrigation management) and diluted with sufficient freshwater to maintain established water- 
qual ity objectives. 



Manage Shallow 
Ground-Water 
to Regulate 
Drainage 
Discharge to 
SJ River 



Pump shallow ground-water systems and/or drainage from on- farm drainage systems and 
discharge the resulting saline effluent into the San Joaquin River during high flow periods 
when sufficient dilution exists to achieve the water-quality objectives. Store saline 
drainage water during dry periods when there is no assimilative capacity within the river. 



FISH & WILDLIFE MEASURES 



Use Financial 
Incentives to 
Protect F&W 
Habitat 

Regulation to 
Protect FiW 
Habitat 

Acquire Lands 
to Protect 
F&W Habitat 

Management of 
Contaminated 
Vegetation, 
Sediment, & 
Soils 

Use Wetlands 
for Winter 
Storage of 
Water 

Allocate CVP 
Yield to 
Wetlands 



Use existing programs to protect habitat (ie, ASCS Water Bank Program, Farm Bill Program) by 
restricting development of wildlife habitat lands for other uses. 



Use a full range of State and Federal regulations to protect existing fish and wildlife 
habitat. 

Use existing State and Federal program funds to purchase private wetlands to enhance existing 
habitat for use by a wide range of wildlife, including endangered species. 

(a) Flush dead and decaying vegetation having accumulated contaminants from wetlands, 

(b) leach contaminated soil with freshwater and a surface and subsurface drainage system, 

(c) contain contaminated material in a reducing environment within sediment by discing, and 

(d) volatilize contaminants by fertilizing lands to increase growth of volatilizing bacteria 
and burning contaminated vegetation. These actions will help decontaminate wildlife habitat. 

Store CVP and SWP water on wetlands to be released and recycled for other uses. Approximately 
50% of the stored water may be recovered. 



Allocate some of the uncommitted CVP yield (available as a result of the Cooordinated 
Operation Agreement) to wetland areas. 



- 71 



TABLE IV-3 
Agricultural Drainage Management Options 



Management Options 

Nonstructural (Institutional 
Modifications) 



Source Control (Water 
Conservation) 



Source Control (Drainage 
Management) 



Source Control (Crop 
Management) 



Source Control (Alternative 
Land Use) 



Drainage Treatment 



Drainage Reuse 



Drainage Disposal 



Water Resources for Fish 
and Wildlife 



Source of Information 

"Farm Water Management Options for Drainage 
Reduction" report by ITAC Agricultural Water 
Management Subcommittee. 

"Fish and Wildlife Resources and Agricultural 
Drainage (SJVDP technical report). 

"Farm Water Management Options for Drainage 
Reduction" report by ITAC Agricultural Water 
Management Subcommittee. 

"Geohydrology of Shallow Ground-Water Areas in 
the Tulare Basin (SJVDP technical report). 

"Selenium in the San Joaquin Valley: Preliminary 
Assessment of Sources, Distribution and Movement" 
(USGS, 1988). 

"Farm Water Management Options for Drainage 
Reduction" report by ITAC Agricultural Water 
Management Subcommittee. 

"The Agroforestry Demonstration Program in the 
San Joaquin Valley" progress report - CDFA. 

"Farm Water Management Options for Drainage 
Reduction" report by ITAC Agricultural Water 
Management Subcommittee. 

"Fish and Wildlife Resources and Agricultural 
Drainage (SJVDP technical report). 

"Drainage Water Treatment, Disposal, and Reuse" 
(SJVDP technical report). 

Drainage Water Treatment, Disposal, and Reuse" 
(SJVDP technical report). 

"Fish and Wildlife Resources and Agricultural 
Drainage (SJVDP technical report). 

Drainage Water Treatment, Disposal, and Reuse" 
(SJVDP technical report). 

"Fish and Wildlife Resources and Agricultural 
Drainage" (SJVDP technical report). 



72 



Management Options 

The management options identified in Table IV-2 have been organized into 
six general categories for purposes of analysis and evaluation. These 
categories are defined as follows: 

Institutional changes -- Modification of existing laws, regulations, 

and policies as appropriate. 
Source control -- Modification of existing on-farm water and land 
management practices to reduce existing and projected drainage volumes 
and reduce salt and contaminant loads. 
Drainage water reuse -- Reclamation of agricultural drainage for a 

variety of potential uses. 
Drainage water treatment -- Removal of total dissolved solids, 
selenium, and other substances of concern from drainage water. 
Drainage water disposal -- In-valley disposal. 
Fish and wildlife measures -- Actions to protect, restore, and enhance 

fish and wildlife resources. 
Eight of the management options identified in Table IV-2 were selected to 
be used in a brief exercise that illustrates some of the analytical procedures 
presented in Chapter III. These options emphasize on-farm irrigation and 
drainage water management. They include: allocation of available water 
supply, changes in irrigation water costs, changes in irrigation technology, 
changes in land use, drainage discharge limit, drainage and effluent fee, 
treatment for selenium removal, and disposal of drainage water. With the 
exception of treatment and disposal, they emphasize nonstructural actions that 
can be pursued in the near future to help solve agricultural drainage and 
drainage-related problems. 



- 73 



Allocation of available water supply . This option assumes a reduction in 
existing agricultural water use, a reduction that would then result in water 
supplies being available for reallocation to other agricultural areas or other 
uses through water marketing or trading. Two key factors are involved in the 
option: (1) Modification of existing contracts between individual water 
districts and the Bureau of Reclamation for the delivery of Central Valley 
Project water supplies, and (2) increased ground-water pumping to offset 
reduced surface-water deliveries. Alternative means of addressing these 
factors will be identified through the institutional analysis discussed in 
Chapter III. 

Other plan features related to this option could include increased 
freshwater deliveries to wetland areas supplied for either: (1) Restoration 
or mitigation purposes to offset adverse effects of agricultural drainage on 
fish and wildlife resources, or (2) storage of freshwater supplies to dilute 
agricultural drainage flows. 

Changes in water costs . Several of the water districts in the drainage 
problem area which contract with the Bureau of Reclamation for delivery of 
surface water have contracts scheduled for renegotiation during the next 
10 years. Based on provisions of the Reclamation Reform Act of 1982, 
contractual prices will increase, with the exception of exchange (water 
rights) contracts. If increased sufficiently, irrigation water prices would 
be expected to encourage more conservation and thereby reduce subsurface 
drainage flows. Potentially, provisions could be included in the renegotiated 
contracts to allow districts to pay only for the water which is actually used 
each year. 

Tiered (increasing block) water pricing by water districts would involve 
higher prices on successive units of water to encourage water conservation and 

- 74 - 



reduce subsurface drainage. Allowing districts to pay only for water actually 
used could facilitate implementation of a district tiered pricing policy. The 
tiered pricing concept could also potentially be incorporated into the 
renegotiated water contracts. A portion of the price increases (whether by 
the Bureau of Reclamation or by water districts) could possibly provide 
funding for costs associated with drainage water management, including 
treatment and/or disposal. 

Changes in irrigation technology . Within the context of the WADE model 
(see description in Chapter III), irrigation technology selections are based 
on the cost of water and drainage management to maximize net farm income. In 
order to analyze the performance of a specific irrigation technology in 
promoting water conservation and reducing subsurface drainage volumes, the 
WADE model selects the one technology (such as shorter furrow lengths, 
sprinklers, or drip irrigation, for example) which maximizes profits for a 
given area, soil, and crop condition. Methods and benefits of improved 
irrigation management (including factors such as irrigation scheduling) are 
also being assessed. The Irrigation Technology Adoption/Diffusion Model will 
be used to predict adoption rate of more efficient irrigation technologies 
(including improved management practices) based on changes in costs and 
income. The effects of modifying irrigation technology will be analyzed in 
combination with other management options, such as increased water pricing and 
drainage management costs. 

Changes in land use . Changes in land use might also help alleviate 
valley drainage and drainage-related problems. One example would be ceasing 
irrigation of agricultural lands with high contaminant levels. Another 
example would be converting land now in irrigated agriculture to wetland or 

- 75 - 



upland wildlife habitat. These changes could result as actions to mitigate 
adverse effects of agricultural drainage on fish and wildlife resources or to 
facilitate increased storage of freshwater during winter and spring months for 
later use in diluting agricultural drainage discharges. 

Drainage discharge limit . Limits might be established on the wasteload 
of drainage effluent from agricultural lands. Such limits could be designed 
specifically to minimize the wasteload and/or encourage the separation of 
surface and subsurface drainage water. Separation of drainage water can 
increase drainage management efficiency by allowing reuse of tailwater and/or 
minimizing the costs of treating drainage water. Discharge limitations could 
also be used indirectly as incentives to retire agricultural lands with high 
contaminant levels or to encourage growers to retain the drainage water 
produced by these lands on their own property. 

Drainage effluent fee . A drainage effluent fee, in addition to being a 
means to repay drainage management and disposal costs, could also be an 
effective economic incentive to reduce the volume of drainage generated. 
Hypothetically, such a fee could be levied on individual growers by existing 
districts or by a regional drainage management authority. Fees could be 
assessed on the basis of volume and quality of drainage generated, location of 
land (upslope/downslope) , amount of deep percolation, etc. 

Drainage treatment for selenium removal . Drainage treatment for removal 
of contaminants could be required at the farm, district, or regional level. 
The volume of drainage to be treated is a very important factor in determining 
total treatment costs and the selection of treatment methods. The increased 



75 - 



cost of farm production associated with a treatment facility will also affect 
grower decisions regarding water conservation measures. 

Disposal of drainage water . Potential drainage water disposal methods 
might include: (1) Discharge to the San Joaquin River, (2) evaporation ponds, 
and (3) deep-well injection. Drainage discharge to the river must comply with 
established water-quality objectives and/or waste load allocation which, in 
turn, may require treatment for removal of contaminants and/or addition of 
dilution water. Evaporation ponds would likely require specific design 
criteria, treatment of influent water, or specific management practices to 
minimize effects on wildlife resources. Treatment would likely be required 
prior to disposal by deep-well injection. Location of the disposal site (on- 
farm, district, or regional) could have differential effects on grower and 
district management behavior. 

Analysis of Options 

The eight candidate options used for illustration purposes are being 
analyzed using the WADE model and other analytical procedures. The WADE model 
assessment includes the effects of alternative options on agricultural 
cropping patterns, irrigation technologies, drainage volume and quality in 
terms of salt concentration, and net farm income. 

The WADE model requires that each option first be expressed 
quantitatively and then introduced as model input data or as a constraint on 
model output. For example, an option such as establishing a drainage effluent 
fee would be entered into the WADE model as an increase in a grower's 
production costs related to the quantity/quality of subsurface drainage 
generated. Another option, such as limiting the quantity of agricultural 
drainage from a district or subarea, would impose a constraint on the amount 

- 77 - 



of drainage that the model would be allowed to produce in its simulation runs. 
Some management options may require more than one input or constraint to the 
model. In the case of district-wide effluent limitations, for instance, costs 
of management and agronomic practices may need to be adjusted to best depict 
the option being analyzed. 

The WADE model is used to simulate the effects of implementing the 
drainage management options described in Table IV-4. The left-hand column in 
the table lists examples of options that were used to design the model runs 
while the second column summarizes the important features of each run. For 
example, the third option example--Irrigation Technology/Drainage Discharge 
Limit--means that the volume of drainage from farms or water districts is 
reduced. 

As shown in the second column, a reduction in drainage discharge can 
result from: (1) Modification of on-farm drainage systems, (2) irrigation 
using furrows 1/4 mile in length with surface water recycle systems (in lieu 
of using 1/2-mile lengths without recycle), (3) separation of surface and 
subsurface drainage water to reduce the amount requiring on- or off-farm 
management (subsurface only), and (4) limitation on drainage discharge to a 
receiving water body, such as the San Joaquin River, to comply with a selenium 
water-quality standard (for example, 5 ppb) . The selenium objective 
represents the limit on the assimilative capacity of the river. 

The third column shows how each feature listed in the second column is 
quantified for introduction to and use by the model. Modification of on-farm 
drainage systems would result in a reduction in subsurface drainage volume of 
30 percent. Irrigation using 1/2-mile furrows without recycle systems would 
be eliminated as an irrigation technology. Separation of surface and 
subsurface drainage is assumed to be accomplished at a cost of $15/acre-foot 
of drainage water; in addition, a physical limit is placed on the amount of 

- 78 - 



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subsurface drainage water produced. Drainage disposal to the San Joaquin 
River is represented in the WADE model by physical limits on the amount of 
drainage generated on-farm. 

The output of the WADE model shows predicted effects on drainage volumes 
and qualities, land use, farm income, and irrigation technology choices. 
Regional economic effects resulting from total farm output and income will be 
separately analyzed. 

The results from each model run are compared to those from the "future- 
without" in order to estimate the effects of each option as illustrated in 
Figure IV-2 (page 64). Options will be screened through this process, and a 
list developed for further analysis and evaluation. Model runs portray 
information, but they do not, alone, eliminate or advance candidate options. 

Additional model runs will analyze combinations of options and address 
important differences among water districts, including agronomic, hydrologic, 
contaminant contribution, and institutional makeup. The Geographic 
Information System will be utilized in specifying WADE model results by water 
district and wildlife management area. 

EVALUATION CRITERIA 

The effects of each alternative option and management plan for the five 
valley subareas are being evaluated using criteria designed to weigh 
significant environmental, economic, social, and institutional effects. How 
well each plan meets the criteria is assessed, and comparisons are made among 
alternatives. The results of these comparisons will provide the basis for 
selecting management options and/or recommending one or more plans composed of 
several options for each subarea. These criteria are discussed briefly in the 
following sections: 



80 



Effectiveness in accomplishing objectives 

Technical feasibility 

Implementation 

Economic efficiency and effects 

Cost allocation and cost-sharing 

Risk assessment 

Environmental performance 

Institutional and legal performance 

Social effects 

Irreversible and irretrievable effects 

Unavoidable adverse effects 

Effectiveness in Accomplishing Objectives 

The intent of this criterion is to provide information on how well each 
option and/or plan accomplishes Drainage Program objectives for public health, 
water quality, fish and wildlife resources, and agricultural productivity. 
Accomplishments are defined in measurable terms such as populations, acres of 
wetland habitat, acre-feet of water supply and drainage, parts per billion of 
selenium, and dollars of income. 

Technical Feasibility 

The technical feasibility of an individual option is measured by its 
efficiency, level of uncertainty and sustainabil ity of performance. Where 
technical feasibility has not been demonstrated (for example, due to low 
efficiency or a high level of uncertainty), the potential for overcoming 
obstacles to assure feasibility will be assessed. 



81 - 



Implementation 

The time required to implement options, the lag time expected before 
benefits will begin to accrue, and the sustainabil ity of benefits into the 
future are measures of this criteria. 

Economic Efficiency and Effects 

The allocation of resources is defined as economically efficient when it 
is not possible to increase the production of any one good without decreasing 
the production of some other good (or goods). The economic efficiency of 
alternative options and plans is determined through a comparison of benefits 
and costs (measured in monetary terms), with the most efficient plans being 
the ones which maximize net benefits. 

Economic effects are the changes in resource uses, employment patterns, 
and income in the local community, region, and State, as well as changes in 
recreational values and other resource stewardship (public trust) values, 
which result from plan implementation and operation. 

Cost Allocation and Cost-Sharing 

Financing and repayment arrangements, developed for each alternative, 
will include an allocation of costs among the purposes served and cost-sharing 
arrangements. Alternative solutions will be analyzed according to the 
following criteria: 

Equity considerations involving who would benefit from, and who would 

pay for, solutions to drainage and drainage-related problems; 
Rationale for cost-sharing among the public and private sectors and 

among Federal, State, and local entities, 
Willingness of the beneficiaries to share costs; and 
Institutional mechanisms for cost sharing and financing. 

- 82 - 



Risk Assessment 

Each option and alternative plan will be evaluated in terms of risk to 
human health and to the total environment, quantifying risk where possible. 
Methods for assessing risk follow those in the Principles and Guidelines. 

Environmental Performance 

* 

The options and alternative plans will be assessed to determine their 
beneficial and/or adverse effects on: (1) Air quality, (2) soil quality, 
(3) surface- and ground-water quantity and quality, (4) climate, (5) fish and 
wildlife habitat, (6) fish and wildlife populations, (7) designated natural 
and recreation areas, (8) cultural resources, and (9) public health. 

Institutional and Legal Performance 

Options and alternative plans are being analyzed from two perspectives 
with respect to laws, regulations, and policies: The feasibility of 
implementing a plan while complying with current laws and governmental 
institutions, and the increased benefits and associated costs (and effort 
required to effect change) which would result from modifying these 
institutions. The costs to society of not modifying current institutions are 
also considered. 

Social Effects 

Options and alternative plans are being evaluated on the basis of how 
well they enhance or, at a minimum, how well they maintain the benefits from 
the social factors which are taken as "quality of life" indicators. Social 
factors include: (1) Public perception of living conditions, health and 
safety risks, and equity; (2) demographics; (3) community services; 



83 



(4) recreation quality and availability; (5) employment, income, and tax base; 

(5) land use, such as agriculture (including prime farmland), wildlife 
habitat, open space, and flood plains; and (7) aesthetics. 

Irreversible Commitments and Irretrievable Adverse Effects 

When any irreversible commitment of resources or irretrievable adverse 
effects are identified for an option'or plan, such options or plans are 
avoided where possible. In cases where irreversible commitments or 
irretrievable losses are unavoidable, they are described in terms of their 
duration, location and magnitude, as well as their social, economic, and 
environmental effects. 

Unavoidable Adverse Effects 

Unavoidable, adverse effects are identified and a mitigation plan 
described including an impact assessment and estimate of implementation costs. 

EVALUATE AND SCREEN OPTIONS 

After each option is analyzed using the appropriate methods, models, and 
procedures, the identified effects are evaluated using the criteria discussed 
above. Similarities among some options allows aggregation for purposes of the 
preliminary evaluation. Although the preliminary evaluations denote the 
relative merits of each alternative option, at this stage of the plan 
formulation and evaluation process little actual screening among options has 
occurred. Rather, the evaluation process so far has provided insight 
concerning at what point each option should be proposed as a part of an 
alternative plan or is likely to be implemented on its own. The process also 
provides a basis for establishing priorities for future research and study. 



- 84 



One of the options (use of wetlands for water conservation storage) has 
been selected to illustrate use of the evaluation criteria. 
Results of a preliminary evaluation by the Drainage Program are shown in Table 
IV-5. This option involves fall/winter storage of high-quality water 
(supplied either from the Central Valley Project or State Water Project) in 
wetland areas to provide additional/improved wintering habitat. This water 
would then be released in the spring for fishery and/or irrigation purposes. 

In order to evaluate this and many of the other options, simplifying 
assumptions are necessary. For the Wetlands Water Conservation Storage 
example, several assumptions are made: 

The schedule of water deliveries to and discharges from offstream 
water storage sites is based on wetland habitat management needs. 
Considerations relating to the quantity and quality of stored water 
are evaluated; however, the sources of water stored, uses made of the 
releases, and related effects are not considered in this preliminary 
evaluation process. 
In the event that this option is not implemented, the following are 
assumed: 

Public wetlands will receive a freshwater supply to replace 
agricultural drainage water determined unusable for wetlands; 
There will be a continuing need for additional wetland water 
supply; and 

Private wetlands will be forced to pay for replacement and 
supplemental supplies. 

FORMULATION OF ALTERNATIVE PLANS AND ESTIMATION OF THEIR EFFECTS 

The formulation of alternative plans is based on a process of selecting 
and combining options into plans to best achieve the Drainage Program's 

- 85 - 



Table IV-5 
Use of Wetland Area for Winter Storage of Water 



Evaluation Criteria 



Evaluation of Wetland Storage Option 



EFFECTIVENESS IN ACCOMPLISHING OBJECTIVES 
Water Quality 

Public Health 
Agricultural Production 

Fish & Wildlife 



Releases from storage increase TDS and some contaminant load levels 
and reduces concentration levels. Seepage from water storage area 
will further reduce contaminant concentration levels in sloughs and 
rivers. 

Reduces contaminates consumed by wildlife and thus diminishes human 
health risks. 

Increases water supply for agricultural or other uses and agricultural 
drainage assimilative capacity of surface streams at the storage 
facility discharge locations. 

Increases water for wetlands habitat, reduces contamination of 
wildlife habitat, and increases river fishery flows. However, may 
attract migrating anadromous fish into waterways that will not support 
fish spawning. 



TECHNICAL FEASIBILITY 



Is technically feasible with sustainable benefits. River water 
quantity and quality and wetland management strategies reguire precise 
timing of discharges from storage. 



IMPLEMENTATION AND SUSTAINABILITY 



Can be implemented immediately with an expected full benefit lag of 
3-10 years, and benefits are expected to be sustainable indefinitely. 



ECONOMIC EFFICIENCY AND IMPACTS 
Cost 
Benefits 



About 50% of the stored water is unrecoverable. 

Has positive net benefits as suggested by preliminary data. 



COST ALLOCATION AND SHARING 



Requires additional institutional mechanisms for cost sharing between 
agriculture and wetlands, and between public and private interests. 
Both public and private wildlife habitat managers have limited 
financing capability to fund this option compared to agricultural 
interests financing capability. 



RISK ASSESSMENT 



Increases mosquito populations. 



ENVIRONMENTAL PERFORMANCE 
Air Qua! ity 
Soil Quality 

Water Quality and Quantity 



Climatic Effects 

Vegetation and Fish & 
Wildlife Habitat 



Fish i Wildlife Populations 



Designated Natural and 
Recreational Areas 

Public Health 



No effect. 

Has potential to increase or decrease soil salinity, depending on 
geographic area and soil types. 

Raises wetland and surrounding area ground-water table and improves 
shallow ground-water quality, but may degrade surrounding ground-water 
quality. Increases river flows; increases TDS loads to river; reduces 
concentration levels in river. 

No effect. 

Has potential for both beneficial and adverse effects, depending on 
species. Significant benefits for wetlands, vernal pools, and 
riparian habitats. 

Has net benefit for the major specie populations with uncertain effect 
on specific endangered populations. 

Includes qualitative benefits for existing designated wildlife areas; 
potential for increasing private habitat acreages. 

Results in fewer contaminated fish and wildlife. 



- 86 



Evaluation Criteria 



Evaluation of Wetland Storage Option 



INSTITUTIONAL AND LEGAL PERFORMANCE 

Legal and Regulatory Obstacles and 
Opportunities 

Formal Institutions 

Informal Institutions 
Time/Cost/Effort to Implement Change 



Requires some reallocation of water 
rights. 

Feasibility will be enhanced by a regional authority that would 
coordinate agricultural and wetland management activities. 

Unknown. 

Requires 3-5 years to establish new or modify authority of existing 
institutions at a modest cost. 



SOCIAL IMPACTS 

Acceptability for Affected Groups and High. 
Interests 



Distribution of Impacts on 
Subpopulations - Labor, Growers, 
Landowners 

Communities - Cohesion, Vitality, 
Infrastructure 



Benefits to groups providing recreational services. 



No effect. 



Land Uses - Agriculture, Habitat, Supports diversity of existing uses. Increases likelihood of 
Development, Recreation, Urban/Suburban maintaining and/or enhancing wetland habitat, open space, and 

prime farmland. 



IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT 
OF RESOURCES 



Increases the use of electrical energy to recover the water 
released from storage. 



UNAVOIDABLE ADVERSE EFFECTS 



Increases likelihood of attracting anadromous fish into the wetland 
area during water release period. 



87 - 



objectives. The analytical techniques and evaluation criteria previously 
described assist in this selection process. As a next step, "major themes" or 
planning emphases provide a focus for considering appropriate combinations of 
options into alternative plans. The major themes will be based on two of the 
Program's objectives: Fish and wildlife resources and agricultural 
protection, with the other two objectives — public health and water 
quality--receiving equal emphasis in all alternatives plans. 

Since it is not possible to precisely predict future fish and wildlife 
and agricultural conditions, plans must maintain the flexibility to adjust to 
changing future conditions. The formulation of alternative plans emphasizing 
either the fish and wildlife or the agricultural theme is expected to produce 
a range of effects likely to bracket most future conditions within the study 
area. 

Plan Analysis (Estimation of Effects) 

Present and future-without conditions and a combination of options 
comprising alternative plans will be analyzed to estimate effects in several 
areas, including: (1) Public health, (2) agricultural production, (3) on-farm 
drainage, (4) regional hydrology, (5) water quality, (6) wildlife habitat, 
(7) fisheries, (8) regional economics, (9) social effects, and 
(10) recreation. Other qualitative analyses will be conducted as necessary 
to provide the basis for complete plan evaluation, with the areas of analyses 
varying among subareas. Alternative plans will be compared to present and 
future-without conditions of each subarea. Thus the relative effects of 
alternative plans will be measured. 

The WADE model will be used to assess the level of agricultural 
production, on-farm drainage, water quality, wildlife habitat, and the net 
farm income part of the regional economics for each plan developed within each 

- 88 - 



theme. To date, the WADE model has been used to develop biannual projections 
for a 5-year period. The model ultimately will be used to simulate economic 
and hydrologic conditions over a 40-to-50-year time horizon, the period 
normally used for planning major water resources management projects. 

Each formulated plan will include a series of on-farm and drainage 
disposal options. For an illustration, the effects of two different plans 
were compared to future-without conditions. The first plan results in a $100 
drainage charge per acre-foot of effluent; the second results in a $20 
drainage charge per acre of irrigated land. The relative effects of each plan 
on total irrigated acreage, total water application, net farm income, and 
subsurface drainage discharge are shown in Figure IV-3. 

The future-without conditions include a constraint on the discharge of 
drainage related to the establishment of water-quality objectives for the San 
Joaquin River and its tributaries. The values of the four variables shown in 
Figure IV-3 (total water applications and irrigated acreage, net farm income, 
and subsurface drainage discharge) would decline significantly in the future- 
without because of the restriction on drainage discharge. However, a levy on 
drainage water generated or acreage irrigated could be used to defray the 
costs of complying with the water-quality objectives and thus permit increases 
in the water application/acreage/income/discharge variables for future-with- 
plan conditions, as shown in the figure. 

A water supply operations model will be used to assess the regional 
hydrology and fisheries effects of alternative plans for each subarea. The 
procedures developed in the California Department of Water Resources Bulletin 
210 will be used to estimate regional economic effects. Estimates of social 
and recreation effects will be based on the analytical methodologies now being 
developed and professional judgment. 



89 



Figure IV-3 



Projected Effects of Alternative Plans 



180 



160 



140 



120 



100 



Percent 

Change 

from 

Future 

Without 0/ ^° 

Conditions 



60 



40 



20 






f 



k 



^■^i^*^^^ 



Alternative Plan #1 

$100. per acre foot 

of Drainage 



Alternative Plan #2 

$20. per acre 

of Irrigated Land 



W^ Total Water Application 

I i Total Irrigated Acreage 

§^M Net Farm Income 

^H Subsurface Drainage Discharge 



£/ Future without coordinated/comprehensive plan. Assumes no means to meeting water 
discharge limitations. 



- 90 



Display of Plan Effects 

Following the example described in the Principles and Guidelines, the 
Drainage Program has adopted four accounts to display the effects of 
alternative plans. These four accounts are: 

National Economic Development, which shows changes in the economic 

value of the national output of goods and services, 
Environmental Quality, which shows effects on ecological, cultural, 
and aesthetic attributes of natural and cultural resources that cannot 
be measured in monetary terms, 
Regional Economic Development, which shows regional economic effects 

including income transfers and employment effects, and 
Other Social Effects, which shows urban and community impacts and 

effects on life, health, and safety. 
The effects of alternative plans, represented as the differences between 
forecasted conditions with and without each of the plans, are displayed in the 
accounts. Relationships between short-term use of the environment and the 
maintenance and enhancement of long-term productivity are indicated in these 
accounts. Any irreversible commitment of resources is also displayed, as well 
as any tradeoffs between the national economic and environmental quality 
objectives. The four accounts cover all significant effects of a plan as 
required by the National Environmental Policy Act of 1959. 

EVALUATION OF ALTERNATIVE PLAN EFFECTS 

The estimated effects of each alternative plan will be evaluated in a 
manner similar to that used in evaluating individual options. Plan 
formulation, analysis, and evaluation will be iterated to refine plans and 
conduct sensitivity analysis. Response curves will be developed to assist 
decisionmakers in understanding the significance of alternative policy 

- 91 - 



options. Evaluation of management options and alternative plans relies on 
numerous assumptions. To evaluate the uncertainty of specific outcomes from 
implementing plans, an analysis will be performed to determine the sensitivity 
of plans to key assumptions. Those assumptions having particularly strong 
influence on the feasibility of a plan feature or alternative will be given 
additional consideration. 

REVIEW AND INVOLVEMENT 
Technical Review 

The technical methods being used by the Drainage Program are subject to 
review at several levels. Advisory comments for the Program are provided by 
the Committee on Irrigation-Induced Water Quality Problems of the National 
Research Council. This committee has established specialized subcommittees to 
give comments in greater detail on the technical methods being employed by the 
Program. The subcommittees are Treatment Technologies, Data Management, 
Economics and Policy, Public Health, Quality Assurance/Quality Control, and 
Systems Analysis. 

Review is also provided by the Interagency Technical Advisory Committee, 
which is a technical review panel composed of experts from various Federal, 
State and local agencies, the California State University system, and the 
University of California system. The Interagency Technical Advisory Committee 
has formed specialized subcommittees in the areas of Agricultural Water 
Management, Data Management, Aquatic Biology and Fishery, Geochemistry, Ground 
Water, Public Health, Treatment and Disposal, and Valley Biology. Other 
reviews are provided on a case-by-case basis. 



- 92 



Local Advisory Groups 

Informal coordination teams made up of local -interest representatives 
such as water district and wetland managers have been established to review 
and comment on preliminary plans for each subarea as they are being 
formulated. These teams will also provide a liaison between the Program and 
the various interest groups to ensure that local actions proposed by the local 
interests are accurately reflected in both the future-without conditions and 
alternative plans formulated by the Program. 

Public Involvement 

Since its inception, the Drainage Program has sought review of its 
activities from various publics and special interests at the local level. 
Organized public involvement began with the formation of a Citizens Advisory 
Committee in March 1987, to provide the Program with information and advice 
from a broad spectrum of organizations and individuals interested in affected 
by drainage and drainage-related problems. The Program plans to continue 
involving local interests through public meetings and workshops hosted by the 
Citizens Advisory Committee at key decision points in the planning process. 

Policy Review and Action 

The Alternative Plans Report and other planning documents which make 
specific recommendations pertaining to Federal or State policies or actions 
will be subject to the review and approval of the Program's Policy and 
Management Committee. Committee members (State, Regional, or District 
Directors for the five lead agencies) have the authority to recommend and 
adopt actions for their respective agencies: California Department of Fish 



- 93 



and Game, California Department of Water Resources, U.S. Bureau of 
Reclamation, U.S Fish and Wildlife Service, and U.S. Geological Survey. 



94 



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95 



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- 96 



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Fujii, R., Deverel, S. J., and Hatfield, D. B., 1987, Distribution of 
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Gates, Timothy K., and Grismer, Mark E., [1988], Irrigation and 
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Gilliom, Robert J., and Clifton, Daphne G., 1987, Organochlorine 

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97 - 



Gilliom, Robert J., February 1986, Selected water-quality data for the 
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Horner, Gerald L., Putler, Daniel S., and Garifo, Susan E., June 1985, 
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98 - 



MacCannell, Dean, 1987, Final report on the structure of agriculture 
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— February 1986, Dissol ved-selenium data for wells in the western 
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--- December 1986, Status of drainage-related studies. State of 
California programs: San Joaquin Valley Drainage Program. 

Quinn, Nigel W. T., 1986, A screening study of management alternatives 
for selenium drainage reduction in the San Joaquin Valley of 
California: San Joaquin Valley Drainage Program. 

San Joaquin Valley Drainage Program, January 1988, Public involvement 
plan. 

--- December 1987, Developing options: An overview of efforts to 

solve agricultural drainage and drainage-related problems in the San 
Joaquin Valley. 

--- June 1987, Developing alternative future-without project scenarios 
for agricultural lands and wetlands in the San Joaquin Valley. 

--- February 1987, On-farm and wetland management practices, summary 
of workshops in Mendota, California, on February 5, 1987 and in 
Hanford California, on February 6, 1987. 

--- February 1987, Prospectus and appendixes. 



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--- December 1986, Project and data directory. 

--- June 1985, Response summary on November 27-30 and 

December 4-5, 1984 public workshops on planning to solve salt 
management and contaminant problems in the western San Joaquin 
Valley. 

San Joaquin Valley Interagency Drainage Program, June 1979, Agricultural 
drainage and salt management in the San Joaquin Valley: Final report 
including recommended plan and first-stage environmental impact 
report: U.S.Bureau of Reclamation; California Department of Water 
Resources; California State Water Resources Control Board. 

Sokolow, Alvin D., Hanford, Priscilla, Hogan, Joan, and Martin, Linda, 
1981, Choices for the unincorporated community: Institute of 
Governmental Affairs, University of California, Davis. 

State of California, 1987, Regulation of agricultural drainage to the 
San Joaquin River: Appendix G, Volume 1, State Water Resources 
Control Board. 

State of California, 1979, California water atlas. 

State Water Resources Control Board, Technical Committee, August 1987, 
Regulation of agricultural drainage to the San Joaquin River. 

U.S. Bureau of Reclamation, November 1987, An evaluation of wetland 
habitat for offstream storage: Final Report. 

— July 1987, Water quality analyses west side San Joaquin Valley. 

— 1986, Crop production reports. 

--- 1986, Agricultural, municipal and industrial water reports. 

— 1978, Special task force report on San Luis Unit: Central Valley 
Project, California, 

U.S. Department of the Interior, 1958, Factual report: Broadview Water 
District. 

University of California, Committee of Consultants on Drainage Water 
Reduction, January 1988, Opportunities for drainage water reduction: 
Number 1 in a series on drainage, salinity and toxic constituents, 
University of California Salinity/Drainage Task Force and Water 
Resources Center. 

— January 1988, Associated costs of drainage water reduction: 
Number 2 in a series on drainage, salinity and toxic constituents, 
University of California Salinity/Drainage Task Force and Water 
Resources Center. 



100 



University of California, Committee of Consultants on San Joaquin 
River Water Quality Objectives, January 1988, San Joaquin Valley 
agriculture and river water quality: Number 3 in a series on 
drainage, salinity and toxic constituents, University of California 
Salinity/Drainage Task Force and Water Resources Center. 

--- January 1988, The evaluation of water quality criteria for selenium, 
boron, and molybdenum in the San Joaquin River Basin: Number 4 in a 
series on drainage, salinity and toxic constituents. University of 
California Salinity/Drainage Task Force and Water Resources Center. 

University of California, Division of Agriculture and Natural Resources, 
Irrigation water use in the Central Valley of California: A report 
of the Central Valley Water Use Study Committee, Department of Water 
Resources, State of California. 

Villarejo, Don, 1985, Land ownership in the Grasslands study area. 

Western Water Education Foundation, 1986, Layperson's guide to 
agricultural drainage. 

Westlands Water District, May 1987, 1985-86 water conservation and 
management program, review and evaluation. 

Westlands Water District, January 1985, Water conservation and 
management handbook. 

Westlands Water District, January 1984, Water conservation and 
management handbook. 

Westlands Water District, July 1980, Water supply study. 

Wichelns, Dennis, et al . , January/February 1988, The economic effects of 
salinity and drainage problems: California Agriculture, 

--- January 1988, Farm-level analysis of irrigated crop production 
in areas with salinity and draihage problems: San Joaquin Valley 
Drainage Program. 

Zilberman, David, December 1984, Technological change, government 

policies, and exhaustible resources in agriculture: American Journal 
of Agricultural Economics. 



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GLOSSARY 



Algorithm--A set of well-defined rules for the solution of a problem. 

Alluvial fan--A sloping, fan-shaped deposit formed by a stream at the place 
where it emerges from an upland onto a plain or broad valley. 

Aquifer--A permeable geologic formation that yields water to wells or springs. 

Cal ibrate--Adjust the parameters (values of input data) in a computer model to 
produce correct quantitative results. 

Conjunctive use--Combined use of ground-water and surface-water resources to 
to supply water. 

Corcoran clay--Confining clay layer about 20 feet to 120 feet thick, ranging 
in depth from 200 feet to 600 feet beneath the land surface. 

Cost effective--Low or lowest cost method of achieving an objective or 
performing a task. 

Darcy's Law--Mathematical expression that describes water movement through a 
porous medium. 

Distal --Located away from the point of origin. 

Ethnographic--A descriptive anthropological study of various cultural groups. 

Evapotranspiration--Rate of water loss by evaporation from water bodies and 
soil surfaces and by transpiration from plants. 

Finite difference--The difference between the values of a function at two 
discrete points, used to approximate continuous changes. 

Flux--The amount of water flowing across a given area per unit time. 



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Future-without condition--the most likely condition expected to exist in the 
future in the absence of implementing a proposed plan. Provides the 
basis for estimating the effects of a plan. 

Geographic Information System (GIS)--A graphical means to inventory and 
analyze geographic data. 

Head--The height of a column of water necessary to develop a specific 
pressure. 

Hydraulic conductivity--Rate of water transmitted through a unit cross- 
sectional area of a saturated aquifer as a result of potential head 
gradient. 

Hydrology- -The science that treats the occurrence, circulation, distribution, 
and properties of waters of the earth, and their reaction with the 
environment. 

Input-output model --A model describing the flow of goods and services among 
industries (sectors) and to final markets. 

Irrigation technology--Methods used to irrigate agricultural crops, including 
equipment and management processes. 

Lower confined zone--Saturated aquifer below the Corcoran clay. 

Mass balance--The principle that the total mass of a constituent in a body 
of water is conserved even when subject to hydrologic processes. 

Model --A physical or mathematical system whose behavior is used to understand 
a physical, biological, or social system to which it is analogous in 
some way. 

Net benefits--Gross benefits minus costs, frequently expressed in monetary 
terms. 



Nonstructural --Plan options and features which emphasize management of the 
existing physical environment with at most minor new 
construction. 



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Parameter--A quantity in a physical system or mathematical expression which is 
constant under a given set of conditions and may be different under 
other conditions. Changing it gives various cases of the 
phenomenon represented. 

Piezometric head--Leve1 to which water from a confined aquifer will rise 
under static (non-pumping) conditions. 

Production function--A relationship describing the amount of output that can 
be produced with a given amount of selected inputs and 
technology. 

Scenario--Hypothesized chain of events used to describe possible future 
conditions. 

Simulate--Imitate some or all of the behavior of one system using a different, 
dissimilar system, particularly computer models. 

Solute transport--Transportation of a substance, such as salts, dissolved in a 
solute, such as water. 

Specific yield--The quantity of water which a unit volume of saturated aquifer 
will yield by gravity. 

Steady state--the condition of a body or system in which the conditions do 
not change with time once all initial fluctuations have 
disappeared. 

Sump--A tank or pit which receives and temporarily stores drainage water at 
the lowest point of a drainage system. 

Trace element--An element found in minute quantities in the environment. 

Upper semiconfined zone--Saturated aquifer above the Corcoran clay. 

Verify- -Determine whether an operation in a computer model has been completed 
correctly and that results are consistent with observed values. 



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