Modeling Phosphorous and Sediment Transport in the Cayuga Lake Watershed

Abstract:

Excess sediment and nutrient loading to surface waters, especially nitrogen and phosphorus, is a common and significant problem throughout the United States. While pollution remediation efforts are continuously improving, the most effective treatment remains to limit the source. The southern end of Cayuga Lake, near Ithaca, NY, is listed by the New York State Department of Environmental Conservation (NYS DEC) as an impaired water body for both sediment and nutrient pollution. In an effort to determine appropriate remediation measures and as little is currently known about the pollutants cycling through the lake, the NYS DEC is conducting a large scale investigation to fully understand how Cayuga Lake is impacted by sediment and nutrient pollution.

This study, as part of the greater effort, explores the contribution of phosphorous and sediment from the surrounding tributaries of Cayuga Lake. The evaluation will include an analysis of the sources and transport pathways of these pollutants in the Cayuga Lake watershed using ArcSWAT. Preliminary execution of the model was carried out on two large watersheds thought to be major contributors of phosphorous to the lake. Data from a number of sources are being used to ensure that model outputs provide an accurate understanding of the watersheds. The calibrated model, combined with information from other sources, will help the NYS DEC determine if a Total Maximum Daily Load (TMDL) is an appropriate remediation tool for the south end of Cayuga Lake.