ARS | Publication request: Assessing conservation effects on water quality in the St. Joseph River Watershed

Submitted to: Agro-Environment Symposium
Publication Type: Proceedings
Publication Acceptance Date: March 1, 2008
Publication Date: May 27, 2008
Citation: Flanagan, D.C., Huang, C., Pappas, E.A., Smith, D.R., Heathman, G.C. 2008. Assessing conservation effects on water quality in the St. Joseph River Watershed. In: Proceedings of the AgroEnviron 2008 (Sixth International Symposium AgroEnviron), April 28-May 1, 2008, Antalya, Turkey. p. 12.

Technical Abstract: Agriculture is a major contributor to non-point source pollution of streams, rivers and lakes. The St. Joseph River is a major drinking water source in northeastern Indiana that has been contaminated by chemicals in runoff. A Source Water Protection Initiative project began in 2002, with the focus on evaluating agricultural practices to reduce pesticide losses. Subsequently, this effort then became a part of the US Department of Agriculture’s nationwide Conservation Effects Assessment Project with the focus expanded to include nutrients and sediment as water quality concerns. The Cedar Creek Watershed encompasses about 707 km2, and topography is flat to gently rolling, with many depressional areas, and monitoring is currently being conducted on 12 catchments ranging from 2 to 19,000 hectares. A pair of field sites allows comparisons between the effects of conventional and no-till farming practices on runoff, sediment, nutrient, and pesticide losses. Another pair of small field monitors allows examination of the impacts of surface tile inlets and/or blind inlet drains and associated management practices on water quality there. Eight sampling sites on three sets of larger nested watersheds monitor runoff, nutrients and pesticide losses in the large drainage ditches and in Cedar Creek itself. A network of automated weather stations and soil moisture sensors has been deployed to provide detailed information on the complete hydrologic cycle in the watershed. Laboratory flume studies as well as field rainfall simulation experiments have also been conducted to expand our knowledge of the pesticide and nutrient transport processes. Watershed water quality model calibration and validation utilizing the SWAT and AnnAGNPS models have been conducted as well. This presentation will present results from the past six years, and discuss what we have learned during that time. Many challenges still exist to allow evaluation of the true impacts of conservation practices on water quality.