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Stormwater Management

Stormwater runoff is generated when precipitation from rain and snow melt events flow over land and impervious surfaces and does not infiltrate into the ground. The runoff from streets, lawns, farms, and construction and industrial sites pick up fertilizers, dirt, pesticides, oil, grease and many other pollutants and discharge into our lakes, streams and rivers. This untreated discharge is detrimental to our water quality as it can adversely affect our drinking water supply and environment. Many Best Management Practices (BMP's) such as detention/retention/infiltration basins, are already in place to help keep our water clean.

Lower Gwynedd Township regulates stormwater management which goes above and beyond typical BMP's through a permit that is obtained from the Pennsylvania Department of Environmental Protection (PA DEP) through the National Pollution and Discharge Elimination System Phase II (NPDES)/Municipals Separate Storm Sewer System (MS4). This is a Federal requirement from the United States Environmental Protection Agency (USEPA) that is administered by the State. This NPDES Permit is broken up into six minimum control measures to be regulated and enforced by the Township. These minimum control measures include:

Lower Gwynedd Township has begun monitoring and testing of storm sewer outfalls that have flow during dry periods. The township asks all residents to cooperate with the inspectors, as some outfalls are located on private properties.

For any questions or concerns regarding stormwater or to report illicit discharges to the storm sewer system please call the Township at (215) 646-5302.

Also, please visit DEP's website to learn about changes to the MS4 Program.

There are many ways you can help the Township with its stormwater program and participate in volunteering programs that will keep trash, debris and other pollutants out of the storm sewer system. For more information on ways you get involved with your community, please visit the following sites:

The following links are for informational videos on basin retrofits, rain gardens and saving streams.


Lower Gwynedd Township completed Phase 2 of the Basin Naturalization Project, which was funded through the Growing Greener Grant. The two Township-owned basins located in the open space area of the Spring House Farms Development were retrofitted as part of this stormwater management project. The slideshow below was presented by the EAC to give a background and overview of the entire project.

PECO Green Region Grant Awarded to Lower Gwynedd Township

Lower Gwynedd Township was awarded a $5,000.00 PECO Green Region Grant. The funding was for the installation of a small rain garden project located right outside of the Penllyn Woods Community Center. The project converted an existing mulched flowerbed, draining approximately 2,745 sf of roof area, into a rain garden. The project was completed in the early Summer of 2020.

A Tale of Two Townships

A coalition of municipalities, local and state agencies, NGOs, and citizens is working on a plan to clean up Montgomery County's impaired Wissahickon Creek. The Wissahickon Creek has been designated an impaired waterway. The coalition has come together under an Intergovernmental Cooperation Agreement to address the challenge. Collectively known as the Wissahickon Clean Water Partnership, the partnership has teamed with Temple University and other experts to help identify the watersheds impairments. In the third of a series of interviews with the Pennsylvania Environmental Council (PEC) our own Mark Grey, Lower Gwynedd Township Supervisor, and Upper Dublin Township Manager Paul Leonard, Co-Chairs of the Wissahickon Clean Water Partnership, sat down for a conversation with longtime radio journalist, Josh Raulerson formally from Pittsburgh NPR station 90.5 WESA. Click here to listen to the interview.

Clean Water Partnership-Wissahickon TMDL Alternative

The Wissahickon Creek is beloved to our community, flowing through our landscape from Lansdale to Philadelphia. In 2016, the municipalities of the Wissahickon Creek Watershed joined together to form an unprecedented coalition of towns and sewer authorities working with the Pennsylvania Department of Environmental Protection (PADEP) and the US Environmental Protection Agency (USEPA) to address the long-term health of the creek. This coalition, called the Wissahickon Clean Water Partnership, will be working on a plan over the next two years to develop a shared strategy and to “Own the Solution” for a cleaner Wissahickon Creek.

This voluntary partnership will evaluate the causes of polluted waters and produce a watershed-wide plan to address those causes and make significant improvements to the health of the creek over the coming years. By working together on a coordinated solution, the Wissahickon Clean Water Partnership ensures that local interests are emphasized, that no municipality is alone in combating pollution affecting the Wissahickon, and that municipalities, sewer authorities and taxpayers can keep costs down in the long run. For more information on this initiative please visit the Wissahickon Valley Watershed Association's website at