Home / Information

Stormwater Management

When it Rains, It Drains!

Understanding storm water and how it can affect your money, safety, health and the environment

What Is Stormwater?

Stormwater is water runoff from precipitation that flows across the ground and pavement when it rains or when snow and ice melt.  The water seeps into the ground or drains into storm sewers. These are the drains you see at street corners or at low points on the sides of streets.  Collectively, the draining water is called stormwater runoff. 

Why is Stormwater “Good Rain Gone Wrong?”

Stormwater becomes a problem when it picks up debris, chemicals, dirt and other pollutants as it flows or when it causes flooding and erosion of stream banks.  Stormwater travels through a system of pipes and roadside ditches that make up stormwater systems.  It eventually flows directly to a lake, river, stream, wetland, or coastal water.  All of the pollutants stormwater carries along the way empty into our waters, too, because stormwater does not get treated. It is important that the borough and every property owner manage the runoff from their properties to eliminate or minimize the amount of pollutants in stormwater.

These common individual behaviors have the potential to contribute to stormwater pollution:

  • littering
  • improper disposal of trash and recyclables
  • improper disposal of pet waste
  • application of lawn chemicals
  • car washing
  • changing motor oil on paved driveways
  • improper disposal of leftover paint and household chemicals.

The National Pollution Discharge Elimination System (NPDES) Municipal Small, Separate Storm Sewer (MS4) Program is a United States Environmental Protection Agency (EPA) program administered by the Pennsylvania Department of Environment Protection (PADEP). The main goal of the MS4 program is to protect water quality.  

Conshohocken Borough submitted a Pollution Reduction Plan (PRP) for stormwater discharges from their MS4 to the Plymouth Creek. The intent of this MS4 Pollutant Reduction Plan is to reduce the sediment pollutant loads within in the Plymouth Creek Watershed that drain to the MS4 from within the jurisdiction of Conshohocken Borough. 

Conshohocken MS4 Pollutant Reduction Plan

2018 Annual MS4 Status Report

Restoring Rain’s Reputation: What Everyone Can Do To Help:

Rain by nature is important for replenishing drinking water supplies, recreation and healthy wildlife habitats. It only becomes a problem when pollutants from our activities like car maintenance, lawn care and dog walking are left on the ground for rain to wash away. 

Here are some of the most important ways to prevent storm water pollution:

  • Properly dispose of hazardous substances such as used oil, cleaning supplies and paint. NEVER pour them down any part of the storm sewer system, and report anyone who does!
  • Use pesticides, fertilizers and herbicides properly and efficiently to prevent excess runoff.
  • Look for signs of soil and other pollutants, such as debris and chemicals, leaving construction sites in storm water runoff or tracked into roads by construction vehicles. Report poorly managed construction sites that could impact storm water runoff to us.
  • Install rain barrels or rain gardens on residential property, which capture storm water and keep it on site instead of letting it drain away into the storm sewer system.
  • Report any discharges from storm water outfalls during times of dry weather – a sign that there could be a problem with the storm sewer system.
  • Pick up after pets and dispose of their waste properly. No matter where pets make a mess – in a back yard or at the park – storm water runoff can carry pet waste from the land to the storm sewer system to a stream.
  • Store materials that could pollute storm water indoors, and use containers for outdoor storage that do not rust or leak to eliminate exposure of materials to storm water.

Useful Links:

Source: PADEPs When it Rains, It Drains Brochure. Additional Links To Helpful Information Link to DEP website: http://www.dep.pa.gov/Pages/default.aspx


Borough Administration
400 Fayette Street, Suite 200
Conshohocken, PA 19428

Phone: (610) 828-1092
Fax: (610) 828-0920

Phone: (610) 828-4032
Emergency: 911
Fax: (610) 828-5243


Monday - Friday, 8:30 a.m. - 4:30 p.m.

Police (Non-Emergency)
8:00 a.m. - 4:00 p.m.