Location
The Clear Creek, IA watershed (CCW) drains approximately 270-km2 of east-central Iowa to the Iowa River. CCW is representative of most U.S. Midwestern watersheds regarding land use (predominantly agricultural), soil type/order (Alfisols and Mollisols), and climate (humid, continental). The combination of extensive agricultural activities, increased urbanization, highly erodible soils, and a wet climate on the steep slopes within the CCW has influenced the runoff and erosion processes in the watershed. The Clear Creek watershed currently has available a plethora of biogeochemical data from an existing network of remote and in situ sensors. Analysis of the physical samples collected within the watershed is conducted with state-of-the-art laboratory instruments. In addition to the biogeochemical data that exist for CCW, a detailed history of land use and management practices exists for the watershed. As a result of changing land use coupled with the predominant climate, soil types, and topography, average annual erosion rates are approximately 11 Mt/ha/yr with most of this erosion occurring in the early summer months when high-intensity rains impact bare soil surfaces in the recently planted agricultural fields. Stream destabilization as a result of widespread channelization and drainage system construction has further increased sediment loadings to the stream. The high sediment loads in CCW have been exacerbated by recent flooding resulting from the high-intensity rainfall prompting concern local residents.
