Welcome to Stormwater

The City of Portsmouth is part of four watersheds.

When it rains, or snow melts or water flows into Portsmouth's stormwater system, it will ultimately make its way [or flow] and discharge into one of the following watersheds (arrows indicate direction of flow).

  • 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, cigarette butts and other pollutants. Many times, rainfall events result in the closure of clam beds for 48 hours or more. 

Residents are reminded to avoid dumping fall yard waste near wetlands or bodies of water, as decomposing leaves and branches can negatively impact aquatic creatures and organisms in water bodies. For more information, click here


Stormwater Map