Welcome to the Stormwater Information Center

What is Stormwater?

Think Blue!Stormwater catch basin with leaves

"Blue"* is the City's mascot for clean water and advocate for stormwater contamination reduction efforts the City, residents and private property owners can make to keep the Portsmouth watershed healthy.

Stormwater is water from rain or melting snow/ice that doesn't soak into the ground but instead runs off into roadways, storm drains and natural water resources. Roofs, driveways, lawns and other streetscapes and landscapes -- where water collects contaminants -- collect stormwater. Unmanaged, stormwater can be a bad thing.

Map of Portsmouth watershed

Where does Portsmouth's stormwater go? 

When it rains, or snow melts or water flows into Portsmouth's stormwater system -- the stormwater and/or wastewater pipes. From there, stormwater make its way into one of four key watersheds:

Portsmouth Harbor Watershed

Berry's Brook-Rye Harbor Watershed

Winnicut River Watershed

Great Bay Watershed

As storm water flows (or snow melts, etc.), it picks up debris, chemicals - such as fertilizers and pesticides - dirt, pet waste, trash including plastics, cigarette butts and other pollutants and even bacteria. Many times, rainfall events result in the closure of local clam beds for 48 hours or more. 

Stormwater can cause or aggravate problems including flooding, erosion and water pollution.

And while the City takes steps to reduce and direct stormwater, private property owners are responsible for about 71% of all the land that collects stormwater, so individual efforts are key to managing the problem.

Learn more about the History of Stormwater Management in Portsmouth.

For a slideshow presentation of the current City of Portsmouth Stormwater Management effort, click here.


*Blue was designed by Portsmouth High School student Jane Almeida.