Genesee River Watershed Project. Volume 2. Water Quality Analysis of the Upper Genesee River Watershed: Nutrient Concentration and Loading, Identification of Point and Nonpoint Sources of Pollution, Total Maximum Daily Load, and an Assessment of Management Practices using the Soil Water Assessment Tool (SWAT) Model. A report to the USDA.

Abstract

An assessment of the Upper Genesee River (UGR) watershed was undertaken to determine sources of nutrient and sediment loss geospatially within the Upper Genesee River watershed and to determine the nutrient and sediment contribution (load) of this segment to the Lower Middle Main Stem of the Genesee River. To accomplish this task, a multifaceted, integrated approach was taken by a combination of monitoring, segment analysis, and modeling (Soil and Water Assessment Tool). To achieve this goal, the river was routinely monitored for discharge, water chemistry, and loss of nutrients and soil for an entire year (3 August 2010 to 23 August 2011) at the USGS gauging station at Wellsville and at Portageville, NY. The Upper Genesee River Soil and Water Assessment Tool (UGR-SWAT) model was created, calibrated, and verified for discharge, sediment, and phosphorus loss using these data. Based on the measured loading data to a subbasin outlet and the SWAT model, segment analysis was performed on selected subwatersheds to determine sources of material loss. The information derived from segment analysis, the SWAT model, and the total amount of nutrients, sediments, and bacteria lost from the watershed served to direct watershed management. Lastly, the UGR-SWAT model was employed to test the effectiveness of BMPs on land use and to determine the minimum potential phosphorus concentration expected in a forested Upper Genesee River watershed as a nutrient target for TMDL development.