Urban Impacts of Water Supply Reservoir

Water quality of Lake Houston, a rapidly urbanizing water supply reservoir near Houston, Texas, was characterized in terms of sediments, nutrients, and algal population. Data was collected at five in-lake stations and all the tributaries, on a weekly basis during 1979. Analyses showed major water quality differences between the urbanized tributaries to the lake and the forested tributaries. Frequent storms and silty soils cause very high turbidities in the lake, which in turn limit the algal population by storm wash-out and light restriction. Algal productivity rate is highly controlled by seasonal factors, such as light and temperature. Two equations were developed relating physical factors (i.e., flow rate, turbidity, and water temperature) to biological factors (i.e., chlorophyll a\aM and algal productivity rate). A suggested set of management strategies was also developed.