Our Watersheds

What is a Watershed?

A watershed is any area of land where water from rain or snow drains into a body of water, such as a stream, creek, river, lake, or ocean.

Philadelphia is part of the Delaware River Watershed. Its seven main subwatersheds are the Delaware Direct, Schuylkill, Pennypack, Tookany/Tacony-Frankford, Darby-Cobbs, Poquessing, and Wissahickon.

The Philadelphia Water Department is committed to protecting and restoring our area’s watersheds to ensure a healthy environment and a clean supply of drinking water.

A simple cutaway diagram of the land around Philadelphia shows it raining on hills and land at higher elevation, flowing downhill until it collects in the nearest creek or stream. Those waterways keep flowing downhill, joining larger creeks and rivers. Philadelphia is at the intersection of two of these rivers, where the Schuylkill joins the Delaware, so all the rainwater from the city and areas upstream that wasn't absorbed into the ground ends up in our rivers.

Philadelphia Watershed History

Learn how Philadelphia’s rapid growth as an industrial hub informed development patterns and altered the natural hydrology and topography of the city’s watersheds.

Learn more →

Black-and-white drawing of Philadelphia in the early 18th century, showing roads, houses, other types of buildings and streams

Improving Our Watersheds

What we’re doing

PWD is committed to keeping our watersheds clean and healthy through initiatives like:

What you can do

Find out what you can do as a homeowner, community group, business, or institution to improve your watershed.