iDavid Freed

What is a Watershed

A watershed is an area of land that channels rainfall and snowmelt to a common body of water, such as creeks, streams, and rivers. The Wissahickon watershed is 64 square miles and covers portions of Montgomery and Philadelphia counties. It is defined by the land-area where rainfall and snowmelt flows into the Wissahickon Creek and its tributaries.


We work in the Montgomery County portion of the Wissahickon watershed. Our downstream partners, Friends of the Wissahickon, work in the Philadelphia portion of the watershed.

The Wissahickon watershed with our nature preserves highlighted.