Genesee River Watershed Project. Volume 1.Water Quality Analysis of the 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

The Genesee River Project, conducted from August 2010 to August 2013, provides a detailed picture of sediment and phosphorus concentrations (e.g., weekly water chemistry sampling), nutrient loading, allocation and identification of phosphorus sources, and the effectiveness of management practices on the four major Genesee River tributaries (Canaseraga, Honeoye, Black, and Oatka Creeks), the Upper Genesee River, and the lower Genesee River. With 60% of the P load (412,505 kg P/yr) from the Genesee River to Lake Ontario being of anthropogenic origin, a managed reduction in P lost from the Genesee watershed is apparent. Models using the Soil and Water Assessment Tool (SWAT) were developed and segment analysis performed on these subbasins to determine sources of material losses. Together these two bodies of information, the total amount of nutrients and sediments lost from the watershed and the sources of these losses, served as a tool for suggesting a watershed management strategy. SWAT models were employed to test the effectiveness of best management practices (BMPs) on land use and to determine the minimum potential phosphorus concentration expected in the subwatersheds. Simulations of BMPs of management practices on both point and nonpoint sources indicated that phosphorus, a valuable nutrient to crop production, can be effectively kept in the watershed and out of Lake Ontario, where elevated phosphorus stimulates algae production and is implicated in beach closings in the Rochester Embayment. Using our most effective simulated scenario, grassed waterways and upgrading of wastewater treatment plants to tertiary treatment, a 32.9% (135,714 kg P/yr) reduction in P loading from the Genesee River to the nearshore of Lake Ontario with Genesee River concentrations at 65 ?g P/L is predicted - within the debated target goal of 65 ?g TP/L for streams in New York State. Volume 1 covers the entire watershed while volumes 2 to 6 report on specific tributary watersheds. The P load allocation analysis indicates that 60% of the total phosphorus load to Lake Ontario is due to anthropogenic sources and only 40% is due to natural sources.