Presented in this report are results of a model study in which methods to reduce channel degradation were investigated. The model studies were conducted during the period July 1979 to April 1980 at the Mead Hydraulic Laboratory near Mead, Nebraska. Channel degradation occurs when the amount of sediment leaving a river reach is greater than the amount entering that reach. Depending upon the magnitude of the degradation, it may have numerous adverse impacts on man and the environment. Channel degradation can leave water supply intakes for powerplants and municipal water systems high and dry; undermine bridge foundations, expose pipeline crossings; render ineffective bank stabilization works; increase farmland erosion; degrade water quality; lower the adjacent water table thereby depleting ground water reserves, wetlands, and lakes. Tributaries to the degrading stream would also be subject to degradation thereby greatly multiplying the overall problem. Channel degradation may not always be undesirable. Channel degradation downstream from a hydroelectric plant could add benefits because of the increase in potential energy. In flood-prone areas, channel degradation could reduce the incidence of flooding, and in agricultural areas it could improve interior drainage.
