Stormwater Management

When it Rains it Drains

Welcome to the Horsham Township Stormwater Management Information page.  This page is designed to provide Township residents with quick access to information and resources to preserve and protect clean water in the Township and the Montgomery County regional community.  Horsham Township is actively involved in a variety of programs and initiatives to meet various Statewide and National goals for clean water.  Local residents and businesses have a role to play too, which when combined together will have a positive impact on our environment and the water that is so important to us all.

The Township is actively involved in meeting statutory permitting requirements under state and federal law.  The Township is also active with partners in a variety of programs and strategies to enhance water quality through plantings, mowing strategies, implementation of stormwater management facilities and other "best management practices" (BMPs). 

We hope that you will find this information useful in learning about the requirements as well as tools to use on your own.  For direct information, visit the PA DEP website: Pennsylvania Department of Environmental Protection. 

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.

This is why your assistance is needed to improve local water quality.

Residential Solutions to Stormwater Pollution

Residential Solutions As stormwater flows over driveways, lawns, and sidewalks, it picks up debris, chemicals, dirt, and other pollutants. Stormwater then flows into a storm sewer system or directly to a lake, stream, river, wetland, or coastal water. Anything that enters our storm sewer system is discharged untreated into the waterbodies we use for swimming, fishing, and providing drinking water. It does not go to the water treatment facility.  Polluted runoff is the nation’s greatest threat to clean water. By practicing healthy household habits, homeowners can keep common pollutants like pesticides, pet waste, grass clippings, and automotive fluids off the ground and out of stormwater. Adopt these healthy household habits and help protect lakes, streams, rivers, wetlands, and coastal waters. Remember to share the habits with your neighbors!

10 Ways to Prevent Stormwater Runoff Pollution:

S    Conserve Water by stopping faucet drips

S    Never dump anything down storm drains

S    Pick up after your pet

S    Sweep up driveways and sidewalks

S    Use fertilizers and pesticides sparingly

S    Plant gardens in bare spots

S    Direct rooftop runoff to grass or gardens

S    Check cars for leaks

S    Wash cars at the car wash

S    Compost your yard and organic wastes 

Homeowner Links/Brochures:

Wave of the Future Kids’ Corner

Looking to enlighten our future generations to the importance of our water resources? Check out the links below for materials created by the EPA to help you do so.

Ways to Help Limit Stormwater Runoff Volume


Rain Garden A rain garden is a planted shallow depression designed to catch and filter rainfall runoff.  The garden captures rain from a downspout or a driveway.  The water sinks into the ground, aided by deep rooted plants that like wet and dry conditions.  A residential rain garden should dry out between rains and should only hold water for approximately 24 -72 hours.  This timeframe prevents standing water that could create mosquito habitat.  For more information on how to create your own rain garden, visit


Rain Barrell Rain barrels are installed at the bottom of your down-spouts and catch the rain water that comes off the roof.  You can then reuse that water to water your garden or yard.  Please try to empty your rain barrel between rain events to maximize the effectiveness of the rain barrel.  


Plant Trees As we remove forest canopy and replace it with roads, parking lots, driveways, homes, patios, pools (impervious surfaces) and even grass, we immediately have impact on watersheds and receiving streams.  Planting trees, shrubs and/or plants that have a deep root structure help stormwater infiltrate into the ground.  They also catch rain water on their leaves and branches which helps to reduce the amount of run-off during a storm. For more information on trees to plant in our region, visit PA DEP Native Plants & Trees

Pet Waste and Water Quality

Pet Waste Did you know the deposit Fido made on the lawn this morning is a growing threat to our environment? Did you also know that studies have found that 40% of pet owners do not pick up after their pets?  The average dog produces a half a pound of waste per day. If 40% of the pet owners in Montgomery County don’t pick up after their four-footed friends, the dog waste is left behind on the ground to decompose or be carried away by stormwater runoff to our creeks and waterways.

When pet waste reaches our waterways, the untreated bacteria, nutrients and parasites contaminate the water and pose health risks to humans and other animals. Don’t let your dog be a canine sewage pipe. Flush your dog’s waste down the toilet, toss it in the trash or better yet, get a doggy composter.

Be a responsible pet parent; always remember to Stop, Stoop and Scoop.  Your pet(s) and the environment will thank you!

Use the link below to view the EPA's guidelines and Best Management Practices (BMP) in regard to pet waste and the impact on water pollution.

EPA: BMP's on Pet Waste Management

Examples of Stormwater Pollution

Stormwater Pollution

Stormwater Pollutants include sediment, sand, cigarettes, litter, cooking oil and grease, paint, automobile fluids, yard wastes, pet waste, pesticides, and fertilizers.


Business Solutions to Stormwater Pollution

Stormwater Pollution Business Businesses also need to be aware that things they do or products they use in their daily operations can enter the stormwater system and affect our water sources. Runoff from construction sites, spills at fueling areas and chemicals used to keep outdoor areas clean can be picked up by rainwater and whisked into the storm sewer system.

Vehicle wastes are among the many common stormwater pollutants that can degrade water quality. Stormwater runoff from vehicle maintenance and repair wastes has been found to contain high concentrations of metals, organics, oil and grease. When these wastes wash into our waters they can kill aquatic organisms. Metals such as chromium, cadmium, lead, and zinc have the potential to contaminate drinking water supplies as well as bio accumulate in aquatic life. Organics such as engine degreasers, cleaners, and other solvents can also degrade water quality.


Fats, Oils & Grease (FOG)

·         Use a FOG recycling/rendering service that provides watertight outdoor receptacles of adequate size.

·         Clean-up FOG spills as soon as they occur. Develop a "spill plan."

·         Use dry clean-up practices to scrape, wipe or sweep FOG from utensils, equipment and floors prior to using wet clean-up methods.

·         Don't hose FOG waste down storm drains.

·         Improper disposal of FOG may lead to by-products in wastewater treatment plants and stormwater systems.

·         Schedule FOG pick-ups related to volume of FOG generation.

·         Maintain pavements and exterior grease traps.


Storage Container Safety

·         Outdoor storage containers should be water tight, rodent proof & protected from tampering.

·         If materials aren't stored properly, pollutants can leak from stockpiles and containers and run out onto the ground.

·         Reduce risk to environment by reducing the amount of materials and wastes kept in storage.

·         If materials must be stored outside, construct a covered, paved area designed to contain leaks and spills.

·         Regularly clean up around dumpsters.

·         If a dumpster leaks, immediately repair or replace it.

Preventing & Cleaning Up Spills

·         Don't allow open containers or tanks that are being filled to be left unattended.

·         Use a funnel when transferring liquids from one container to another.

·         Place trays under open containers and the spouts of liquid storage containers.

·         Buy products in smaller quantities whenever it’s cost effective.

·         Design work areas to contain spills.

·         Absorbent materials used to clean up hazardous substances must be disposed of as hazardous waste.

Business Links/Brochures:

Construction Industry Information

Stormwater Pollution Construction The construction industry has a key role to play in stormwater management. As stormwater flows over a construction site, it can pick up pollutants such as sediment, debris, and chemicals. Uncontrolled erosion has a significant financial impact on a construction project. It costs time and money to repair gullies, replace vegetation, clean sediment clogged storm drains, and mitigate damage to other people's property.

Installing and maintaining pollution prevention techniques on site can reduce the potential for stormwater pollution and help protect our nation's water supply.

  •  Minimizing the amount of exposed soil, because the less soil that is exposed the easier and cheaper it will be to control erosion. Sequence construction activities so that the soil is not exposed for long periods. Schedule site stabilization activities such as landscaping to be completed as quickly as possible after the land has been graded to the final contour.
  • Identify and protect areas where existing vegetation such as trees will not be disturbed by construction activity.
  •  Protect streams, wild woodlands, wetlands, and other sensitive areas from any disturbance or construction activity by fencing or otherwise clearly marking those areas.
  • Silt Fencing:   Inspect and maintain silt fences after each rainstorm. Make sure that the bottom of the silt fence is buried in the ground. Securely attach the material to the stakes.
  • Construction Entrances:  Make sure the construction entrance doesn't become buried in soil. Regular street sweeping at construction entrance will prevent dirt from entering storm drains.
Construction Links/Brochures:

Clean Water Act

Clean Water Act The Clean Water Act is the federal legislation that governs stormwater management. Stormwater point discharges to waters of the U.S. are regulated using National Pollutant Discharge Elimination System (NPDES) permits. In 1999, federal regulations extended coverage of the NPDES program to local separate storm sewer systems (MS4’s) serving populations less than 100,000. Horsham Township is required to comply with the NPDES program as a MS4. Under the NPDES stormwater program, permittees must develop a stormwater management plan that provides the details of how the community (Horsham Township) will comply with the requirements of the permit. Permits are based on a framework of six minimum control measures:
  • Public education and outreach
  • Public participation and involvement
  • Illicit discharge detection and elimination
  • Construction site runoff control
  • Post-construction storm water management in new development and redevelopment
  • Pollution prevention and good housekeeping for municipal operations and maintenance

More information on this program is available from the Pennsylvania DEP website

Rain Water Collection Activity

Fact: 1" of rainfall on a 1000 sq. ft. roof will produce 600 gallons of rainwater. To calculate the square footage of your house, you can measure the outside area of the exterior walls. To find area, multiply Length times Width. Using an example of a house that is 50' in length by 35' in width, we would multiply 50' x 35' to equal 1750 sq. ft. Move the decimal point over 3 places to the left to continue the equation.

Since 1" of rain yields 600 gallons on a 1000 sq. ft. roof, we will multiply 600 x 1.75 to determine the quantity of run-off from our example roof. 600 x 1.75 = 1050 gallons.

For every one inch of rainfall, then, approximately 1050 gallons will drain off of the roof.

To determine an annual rooftop yield for a 1000 sq. ft. roof in Montgomery County, we take the average rainfall, determined to be 44.35" according to, and multiply by 600 gallons. 44.35 x 600 = 26, 610 gallons of rainfall.

How much rainwater can be collected from your roof?

Horsham Township Municipal Separate Storm Sewer Systems (MS4)

The goals of all MS4s programs and Horsham Township are to reduce the discharge of pollutants from the township, to protect water quality and to satisfy requirements of the Clean Water Act. Horsham Township would like you to remember that the water and any items that go into a storm sewer go directly into streams. This water is not cleaned in any way and does not go to the waste water treatment plant. Horsham Township needs all of its residents to assist us in keeping our storm water and storm water sewer system clean by doing the following: dispose of water properly, clean up after your pets, use fertilizers properly and efficiently to prevent excess runoff and store materials that could pollute storm water indoors. Also, please monitor storm water inlets near your property. No one should dump anything into the storm sewer system. If you see someone dumping please call the township at 215-643-3131.

EPA Fact Sheets:

Storm Drain Stenciling:

Storm Drain Stencil Horsham Township has been marking the storm drains in the township with the "No Dumping / Drains to Creek" stencils. Horsham Township with the assistance of many volunteers has marked most of the storm drains in the Township. These storm drain stencils educate the public that anything you dump into the storm drain ends up directly in a creek or other public water way. If you would like to volunteer and help with storm drain stenciling: check your neighborhood for missing stencils and then call Mark Hudson at 215-672-3131. Let us know the number of stencils you need and we can drop them off to you so that you can put them on. 

 What Residents Can Help Watch For:
  • Sediment leaving a construction site in stormwater
  • Spills (chemical, gas, oil)
  • Illegal dumping activity into streams or storm sewers (please all 9-1-1 first)
  • Dry weather flows from outfall pipes in streams (72 hours after a rain storm)
Residents may be the first to recognize "illicit" discharges dumping into storm sewers or coming out from storm sewer outfalls.  if you see an "illicit" discharge, please report it to Horsham Township by the following methods:

Call Mark Hudson at (215) 643-3131 or email: [email protected]

Watersheds in Horsham Township

A watershed is made up of the land area that drains to a specific body of water, such as a tributary, stream or river. The topography of our local hills and valleys define the watershed boundary (catchment area) and the watershed outlet is the mouth of a pond, river or lake.  There are three (3) watersheds that run through Horsham Township, they are:

  • Neshaminy Creek
  • Pennypack Creek
  • Wissahickon Creek

Watershed Links/Brochures: