Illinoise River Basin, polllution, water quality, water monitoring, Arkansas
The Illinois River Basin has experienced water quality impairment from non-point source pollution for many years. This fact was well documented in the State of Arkansas' Water Quality Assessment report, the Soil Conservation Service River Basin Study, and several University of Arkansas studies. Thirty-seven sub-watersheds have been identified by the SCS in the Arkansas portion of the Illinois River basin. In the Arkansas portion of the Basin, the Illinois River, Evansville Creek, Baron Fork, Cincinnati Creek, Muddy Fork, Moores Creek, Clear Creek, Osage Creek and Flint Creek were all classified as not supporting their designated use as primary contact recreation streams. The identified causes of the impairment were: sediment, bacteria and nutrients. In 1997, the University of Arkansas completed a project that estimated the phosphorus loading from each of the thirty-seven sub-watersheds. This project also prioritized watersheds for implementation work based on phosphorus loads, nitrogen loads and total suspended solids loads per unit area. The thirty-seven sub-watersheds were grouped into Low (16), Medium (10) and High (11) categories based on phosphorus loadings. If all the sub-watersheds above the median value for on phosphorus loading in the Illinois River basin were brought down to the current median value for phosphorus loading, this reduction would result in the agreed to 40% reduction of phosphorus at the state line. The selection of a sub-watershed for targeted intensive voluntary BMP implementation was based on the following criteria: a) the sub-watershed had to be above the current median value for phosphorus loading, b) there would be no sewage treatment plant in the sub-watershed, and c) land user interest. The Upper Ballard Creek watershed met all these requirements. The watershed covers 6700 hectares. The creek is listed in the High category with a unit area loading of 1.75 kg. per hectare per year. The median value for the thirty-seven watersheds is 0.73 kg. per hectare per year.
Nelson, Marc A.; Cash, L. Wade; Trost, G. Keith; and Purtle, Jennifer. 2005. Water Quality Sampling, Analysis and Annual Load Determinations for TSS, Nitrogen and Phosphorus at the Washington County Road 76 Bridge on Ballard Creek. Arkansas Water Resources Center, Fayetteville, AR. MSC323. 14