Illinois River CREP: Sediment and Nutrient Delivery Assessment

The Illinois River Conservation Reserve Enhancement Program (CREP) was initiated as a joint federal/state program with the goal of improving water quality and wildlife habitat in the Illinois River Basin. Based on long-term data and research, the two main causes of water quality and habitat degradations in the Illinois River were sedimentation and nutrient loads. To address these issues, the two main objectives of the Illinois River CREP are: 1) reduce the amount of silt and sediment entering the main stem of the Illinois River by 20 percent, and 2) reduce the amount of phosphorous and nitrogen loadings to the Illinois River by 10 percent. To assess the progress of the program towards meeting the two goals, the Illinois Department of Natural Resources (IDNR) and the Illinois State Water Survey (ISWS) are developing a scientific process for evaluating the effectiveness of the program. The process includes data collection, modeling, and evaluation. The monitoring and data collection component consists of a watershed monitoring program to monitor sediment and nutrient for selected watersheds within the Illinois River Basin and the collection and analysis of land use data throughout the river basin. Data collected at the monitoring stations and long-term data collected by other agencies are being used in evaluating the trends in sediment and nutrient delivery to the Illinois River. The paper presents results of the assessment based on available data.