Suspended-Sediment Yields and Stream-Channel Processes on Judy’s Branch Watershed in the St. Louis Metro East Region in Illinois

Judy’s Branch watershed, a small basin (8.64 square miles (mi2)) in the St. Louis Metro East region in Illinois, was selected as a pilot site to determine suspended-sediment yields and stream-channel processes in the bluffs and American Bottoms (expansive low-lying valley floor in the region). Suspended-sediment and stream-channel data collected and analyzed for Judy’s Branch watershed are presented in this report to establish a baseline of data for water-resource managers to evaluate future stream rehabilitation and management alternatives. The sediment yield analysis determines the amount of sediment being delivered from the watershed and two subwatersheds: an urban tributary and an undeveloped headwater (primarily agricultural). The analysis of the subwatersheds is used to compare the effects of urbanization on sediment yield to the river. The stream-channel contribution to sediment yield was determined by evaluation of the stream-channel processes operating on the streambed and banks of Judy’s Branch watershed. Bank stability was related to hydrologic events, bank stratigraphy, and channel geometry through model development and simulation.