Watersheds range in size from less than one acre to thousands of acres. Smaller watersheds, which are centered around a single creek or stream, combine into larger ones. There are six major watersheds, or basins, in Pennsylvania: the Ohio River, Delaware River, Potomac River, Genesee River, Lake Erie, and the Susquehanna River. Nearly all of Lancaster County’s watersheds are part of the Susquehanna River basin, which is part of the larger Chesapeake Bay watershed. In fact, the Susquehanna River provides about half of the freshwater that flows into the Chesapeake Bay!

The water in our creeks and streams comes from groundwater – water stored underground in layers of rocks – as well as surface water like rainwater and snowmelt. As water travels over the land, it can pick up pollutants like fertilizers, pesticides, pet waste, and soil, and carry them into our streams. What you do on land directly impacts the health of the cricks and creeks in your watershed. The first step to supporting healthy waterways is learning which watershed you live in!