Sedimentation and Hydrologic Processes in Lake Decatur and Its Watershed

摘要

One of the end products of erosion is the accumulation of sediment in lakes and reservoirs, which results in the degradation and impairment of use of these water bodies. Lake Decatur, a water supply reservoir in the Upper Sangamon River watershed in east-central Illinois, has lost one-third of its storage capacity to sedimentation since its construction in 1922. The report includes information on the history of the lake and on the physical and geological characteristics of the Upper Sangamon watershed. Changes in reservoir storage capacity over time and the temporal, spatial, and geotechnical variations in sediment deposition are analyzed. Over the period 1922-1983 Lake Decatur lost 9100 acre-feet of storage capacity through the accumulation of 9,830,000 tons of sediment.