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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.

Streambank Restoration Project- Township Awarded Grant

Lower Gwynedd Township is pleased to announce that the Old Bethlehem Pike Streambank Stabilization & Enhancement Project was approved for a Watershed Restoration Protection Program Grant at the April 21, 2021 Community Financing Authority (CFA) Board meeting in the amount of $100,000.00. The Pennsylvania Department of Community and Economic Development's Watershed Restoration & Protection Grant Program is funded through monies allocated under Act 13 of 2012, the Marcellus Legacy Fund.  The CFA is an independent agency of the DCED responsible for administering Pennsylvania’s economic stimulus packages.

This project will repair eroded streambanks within the Willow Run tributary to the Wissahickon Creek. The project stream segment is located off of Old Bethlehem Pike directly behind the Lower Gwynedd Township Municipal Building. The scope of this project includes the stabilization and enhancement of approximately 300 linear feet of stream (both sides) from 100 feet upstream of the Old Bethlehem Pike bridge and 200 feet downstream. The restoration work will re-establish and stabilize the bank and restore the area to its natural function. The project will help control erosion in the future and protect the streambank. We also anticipate that the restoration and enhancement will reduce the amount of sediment and other pollutants from entering the stream and improve water quality throughout the watershed.

Stormwater Article

Keep Your Soil at Home

Believe it or not, one of the biggest threats to our water quality is plain old dirt washing into our rivers from lawns, roads, driveways, and construction sites. The top soil is an important resource for your yard. However, when the soil is lost through erosion it becomes a pollutant called “sediment.” Water flowing from your yard during rain or snow melt carries sediment, and the other pollutants that attach to sediments, to our local streams.

What’s Wrong with Sediment?

Sediment clouds and reduces sunlight for stream plants that provide habitat and oxygen for fish. Sediments fill in the spaces between rocks in stream bottoms and take away fish habitat and habitat for other critters that live on the bottom. Sediment also carries other pollutants such as nutrients, oil, and grease. Excess nutrients in water lead to nuisance algae growth.

Signs of Erosion Include:

  • Exposed tree roots, stones, and rocks
  • Formation of small gullies
  • Buildup of soil in low areas
  • Widening or depending stream channels

What can you do to prevent erosion?

  1. Seed or mulch any bare soil on your property. Plant roots guard soil from rain drops and prevent erosion.
  2. Choose native plants that thrive in our climate. Native plants can grow deeper roots systems that protect soil from erosion. Check with a local nursery for information.
  3. Cover gardens with mulch or leaves over winter to protect plants and reduce erosion when snow melts.
  4. If you observe erosion at construction sites, contact Township Administration at 215-646-5302.

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


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.