Quantification of land-use impact on stream water quality

Accelerated eutrophication of Beaver Lake in northwest Arkansas is a major environmental concern. When developing watershed-management plans to protect lake water quality, it is important that linkages among land-use activities and water quality of tributary streams be quantified. This study assessed longitudinal base-flow and storm-flow water quality at War Eagle Creek and quantified linkages between stream water quality and land-use conditions within the War Eagle Creek sub-watershed of the Beaver Lake watershed. We collected six water samples: three from base-flow conditions and three from storm-flow conditions during Spring 2002. In general, concentrations of nitrate nitrogen (NO3-N), total N (TN), total organic carbon (TOC), conductivity, and total dissolved solids (TDS) increased as the sampling moved downstream. All stream water-quality parameters, except phosphate phosphorus (PO4-P), were significantly correlated to the ratio of agricultural-to-forest land-use (r2 = 0.90 to 0.97). These results indicate that the ratio of agricultural-to-forest land-use within the watershed can be used to evaluate stream water quality, and that increases in this ratio may result in increased TDS, NO3-N, TN, and TOC concentrations