This report summarizes the results of a two-year study on the determination of the input of sediment to Peoria Lake from its local tributaries. Ten local tributaries were monitored to determine the flow of sediment and water. Long- term average deposition of coarse material at the mouths of these tributaries was estimated as bed load based on the progression of the deltas at the base of the tributaries. Sediment inflow to Peoria Lake from the Illinois River was determined based on the estimated sediment load at the Henry gaging station. Water year 1989 (WY89) was essentially a dry year and WY90 was average. The present analyses have shown that about 1.2 million tons of sediment flowed into Peoria Lake in WY89 and about 2.7 million tons of sediment flowed into the lake in 1990. Because of a lack of a sedimentation survey and nonavailability of sediment outflow data from the lake, no sediment budget for the lake was determined. However, this analysis indicated that in WY89 the sedimentation rate in Peoria Lake was probably less than that determined on a long-term basis in a previous Water Survey study, while sedimentation in WY90 was probably close to or a little less than that postulated in the earlier study. Both in-lake and tributary sediment input controls should be initiated. They should include selective dredging and construction of wetlands, marshy areas, and bank and grade control structures. Implementation of any sediment control measure must be preceded by a systematic and systemwide evaluation of each tributary to determine the most effective combination of sediment control measures for maximum reduction of sediment deposition in the lake.