We use the Soil and Water Assessment Tool (SWAT) to model DRP in the agriculture-dominated Sandusky watershed for 1970–2010 to explore potential reasons for the recent increased DRP load from Lake Erie watersheds. ... Locator map of the Sandusky watershed, Ohio. ... (15) It is a process-based model of weather, surface hydrology, sedimentation, soil temperature, crop growth, nutrients, pesticides, and groundwater that can simulate the effects of climate and agricultural management changes on nutrient and sediment delivery from watersheds. ...