This research was designed to assemble and analyze available data on chemical quality and limnology of reservoirs and river reaches from Lee Ferry to Imperial Dam, to determine the effects of development on salinity and to initiate the validation of models of interaction of chemical ions, sediments, biological factors and other limnological inputs such as thermal stratification and turnover. The study has completed a biological and chemical review of the Lower Colorado River, a statistical and stochastic eutrophication model, an energy-budget model, a cross-spectral analysis salinity model and shown the applicability of remote sensing of water quality. A specific chemical-ion model and aquatic ecosystem model to incorporate the above sub-models is under development. (Author)