Nationally, sediment in reservoirs is a concern as related to several important issues including water quality and reservoir water-storage capacity. The ability to achieve meaningful decreases in sediment loads to reservoirs requires an understanding of the relative contribution from sediment sources within the contributing watersheds. To estimate sources of sediment within the 2,900-km2 Perry Lake watershed of northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), and reservoir bottom sediments were collected, analyzed, and compared. Within the watershed, a nested approach was used in which five representative subwatersheds were selected for sampling. The subwatersheds ranged in size from 20 to 50 km2. Samples were sieved to isolate the <63-micron-size fraction and analyzed for particle-size distribution, nutrients (total nitrogen and total phosphorus), carbon, 25 trace elements, and cesium-137 (137Cs).
Total nitrogen (TN), total phosphorus (TP),
total organic carbon (TOC), and 137Cs were selected as the
constituents that provided the best ability to discriminate between
channel-bank and surface-soil sources of sediment in the