DRAINAGE BASIN MORPHOMETRY AND FLUVIAL GEOMORPHIC RECONSTRUCTION OF THE KILLBUCK-MUD CREEK SUBWATERSHED, DELAWARE COUNTY, INDIANA

The Killbuck-Mud Creek subwatershed is part of the White River watershed north of Muncie, Indiana. The study area is drained by two first order streams, Killbuck and Mud Creek. Wisconsinan glacial till is the primary material found above bedrock in the study area and contributes to the sediment availability. The White River Watershed Project (WRW), a non-profit community and government organization, has identified that Total Suspended Solids (TSS) is the major non-point source pollutant for the subwatershed and have begun to develop management plans to improve all Delaware County, Indiana, surface water quality. The amounts of TSS in the streams have increased as more surrounding forest and wetlands have been replaced with agricultural lands. Since the mid-1800's, most of the first and second order streams of Delaware County have been straightened and dredged for the purposes of agriculture and land drainage. These agricultural lands have more exposed soil and unconsolidated glacial till at the surface causing higher erosional rates, which directly impact stream TSS levels during runoff events. Increasing TSS levels have contributed to the decrease in the amount and diversity of aquatic life in these streams. To lower the TSS levels the WRW has identified stream reconstruction as a possible management plan. The purpose of this study was to create a stream reconstruction plan that effectively lowers TSS levels and slows TSS influx entering the streams from runoff during storm events. Since there are no archived maps, soil studies, or geologic surveys prior to human modification or natural channels for the subwatershed, the use of preserved meanders from outside the subwatershed were used for the primary reference geometries. The preserved meanders are remnants from when the subwatershed drained east to the Mississinewa River prior to a basin capture event. GIS has allowed the drainage basin to be modeled as a stable pre-modification case based on current discharge, storm hydrographs, sediment type and availability, and the preserved meanders. Using the GIS model as a reference, a stream reconstruction plan was created to accommodate current land usage and stabilize the stream channels. The stream reconstruction plan for this subwatershed could be used by the WRW as a template for similar areas in the county.