Sediment transport characteristics of selected streams in the Susitna River Basin, Alaska, October 1983 to September 1984

The upper reaches of the Susitna River have been considered for development of a large power generation system for south-central Alaska. This report presents a summary and discussion of sediment and hydraulic data obtained from October 1983 to September 1984 at ten sites on the Susitna, Chulitna, Talkeetna, and Yentna Rivers. Sediment data include measurements of suspended sediment and bedload discharge and analyses of particle size distribution of suspended sediment, bed-load, and bed material; hydraulic data include measurements of width, average depth and velocity, and water surface slope. Relations between water and sediment discharge are developed for selected sites. Sediment loads for the 1984 water year were estimated for the Yentna, Chulitna, and Talkeetna Rivers and for four sites on the Susitna River. About 25 million tons of sediment was transported by the Susitna River at Susitna Station during the 1984 water year. The Yentna and Chulitna Rivers contributed more than 20 million tons of sediment to the susitna River. About 90% of suspended material (silt, clay, and sand) transported past upstream sites reached Susitna Station during the same period. (Author 's abstract)