This dataset contains polygons showing the extent all sewer systems in the Cayuga Lake Watershed as of September 2007, based upon data provided by individual municipalities in the watershed. This geographic dataset was developed by the Cayuga Lake Watershed Network as part of a larger project, in conjunction with Dr. Douglas Haith and Cornell University, to model nutrient loading in the Cayuga Lake watershed. The model used is the Generalized Watershed Loading Function (Haith and Shoemaker, 1987). Haith, D.A. and L.L. Shoemaker, 1987. Generalized Watershed Loading Functions for Stream Flow Nutrients. Water Resources Bulletin, 23(3), pp. 471-478.