Stormwater Management

What is Stormwater?

Stormwater runoff is generated when precipitation from rain and snowmelt events flows over land or impervious surfaces and does not percolate into the ground. As the runoff flows over the land or impervious surfaces such as paved streets, parking lots, and building rooftops it accumulates debris, chemicals, sediment or other pollutants that can adversely affect water quality. The primary method to control stormwater discharges is the use of best management practices (BMPs).

Why is Stormwater Management Important?

Unlike water that enters our municipal sewage system, stormwater is not cleaned and treated at a wastewater plant before it re-enters our streams and waterways. Stormwater runoff from roads and other impervious areas comes into contact with pollutants and allows those pollutants into our waters. It is essential that municipalities put in place a focused Stormwater Management Program (SWMP) to combat polluted stormwater runoff.

Polluted stormwater runoff is commonly transported through Municipal Separate Storm Sewer Systems (MS4s), from which it is often discharged untreated into local waterbodies. To help to prevent harmful pollutants from being washed or dumped into an MS4, operators must obtain a National Pollution Discharge Elimination System (NPDES) permit through the Department of Environmental Protection (DEP) and develop a stormwater management program.

MS4...  What’s That?

A Municipal Separate Storm Sewer System (MS4) is any municipal-owned stormwater conveyance or system of conveyances. i.e. Township roads, ditches/swales, and stormwater pipes.  East Brandywine Township has to comply with the NPDES MS4 permit through 6 Minimum Control Measures (MCMs):

MCM #1—Public Education & Outreach - East Brandywine Township has made efforts to educate the public about the Stormwater Management Program through several methods, including: the Township website, the Township newsletter, Mile Marker, and the partnership with the Brandywine Valley Association (BVA).

MCM #2—Public Involvement/Participation - East Brandywine Township encourages the public to participate in the stormwater management program decision-making process and routinely communicates with the BVA. The Township’s MS4 Annual Reports are available to the public for review by request.

MCM #3—Illicit Discharge Detection & Elimination - East Brandywine Township maps all of its stormwater features, including: outfalls, surface waters, roads, inlets, pipes, basins, etc. Illicit discharges to the MS4 are prohibited in East Brandywine Township. Outfalls are inspected regularly to verify that there are no illicit discharges and to take the appropriate actions if an illicit discharge is discovered. Examples of illicit discharges include: substances (such as used motor oil, etc.) that have been dumped into a storm sewer or waterbody, wastewater piped directly from a home to the storm sewer, failing septic systems, etc.

MCM #4—Construction Site Stormwater Runoff Control - East Brandywine Township and the Chester County Conservation District (CCCD) ensure that construction sites have adequate Erosion and Sedimentation (E&S) Control Best Management Practices (BMPs) and maintain them throughout the duration of the project to prevent accelerated erosion and sedimentation to the MS4.

MCM #5—Post Construction Stormwater Management in New Development and Re-Development - East Brandywine Township and the CCCD ensure adequate Post Construction Stormwater Management (PCSM) BMPs are proposed and installed properly. Once construction of these BMPs is complete, East Brandywine Township regularly inspects the PCSM facilities to ensure that they are functioning properly.

MCM #6—Pollution Prevention/Good Housekeeping – East Brandywine Township has identified all Township-owned facilities and activities (fleet vehicle maintenance, winter de-icing, etc.) that have a potential to impact stormwater and developed an Operations and Maintenance Program to prevent stormwater pollution. Township employees are regularly trained in all aspects of the Stormwater Management Program.

What is East Brandywine Township Required to Do?

The stormwater requirements of the federal Clean Water Act and the National Pollution Discharge Elimination System (NPDES) are administered under the Pennsylvania Department of Environmental Protection (DEP) and implemented by DEP through the Municipal Separate Storm Sewer Systems (MS4) Program. Almost all municipalities (including East Brandywine) in Pennsylvania must have an MS4 permit.

East Brandywine Township must comply with its MS4 permit through a robust stormwater management program. For more information on the MS4 program go to DEP’s MS4 Resource Page. In order to improve stream and waterway quality, federal regulations establishes Minimum Control Measures (MCMs) that must be implemented through the MS4 program.

The six regulations are:

  1. Public Education and Outreach
  2. Public Participation and Involvement
  3. Illicit Discharge Detection and Elimination
  4. Construction Site Runoff Control
  5. Post-Construction Stormwater Management in New Development and Redevelopment
  6. Pollution Prevention and Good Housekeeping for Municipal Operations and Maintenance
Municipalities meet these MCM requirements through a series of Best Management Practices (BMPs) which are schedules of activities, prohibition of practices, structural controls, design criteria, maintenance procedures, and other management practices that reduce pollution to the waters of the Commonwealth.

For more information on MCMs and BMPs please go to the U.S. Environmental Protection Agency (EPA) MS4 Page where Minimum Control Measures along with the respective Best Management Practices are listed and explained.

How Can You Help?

Start by creating stormwater-friendly lawns and gardens! When the amount of rain falling exceeds the land’s ability to absorb it, the result is stormwater runoff. Without treatment, stormwater that runs from the land into our waterways can be unhealthy for people and bad for the environment. Runoff can carry chemicals, metals, bacteria, viruses, organic compounds, and other pollutants directly into creeks, lakes, rivers, and streams. Runoff can also cause severe erosion and flooding — even during a typical Pennsylvania storm.

Clearly, then, what we do on the land impacts the quality of our water. That means everyone, not just government, plays a role in protecting this valuable resource by reducing runoff and the pollutants it carries. This summer, homeowners can take steps to help with the effort by making sure their gardens and lawns are “stormwater-friendly.”

There are many ways you can protect water quality by preventing stormwater pollution including:

  • Never dump anything in storm drains, streams, wetlands, or lakes.
  • Clean up pet waste.
  • Reduce the use of herbicide, pesticide and fertilizer.
  • Re-vegetate bare spots in your yard to reduce erosion.
  • Report illicit discharges to East Brandywine Township.
  • Have your septic tank pumped and inspected regularly.
  • Check your car for leaks and recycle your motor oil.
  • Properly dispose of yard waste.
The Stormwater-Friendly Garden

Home gardens can contribute considerable nutrients and other pollutants to waterways if not cared for responsibly. This mainly applies to fertilizers and pesticides.

Fertilizers: Instead of using chemical fertilizers, give organic alternatives, such as compost and manure, a try. Compost, a “do-it-yourself” fertilizer that can be created from such things as vegetable scraps and garden clippings, contains the nutrients that help your vegetables grow. When using organic fertilizers, be sure to apply them directly to the ground before planting the vegetables to prevent runoff.

Pesticides: Many insects are harmless to people and play an important role in maintaining a healthy lawn or garden ecosystem. If one is posing a problem, however, identify the exact pest you have and research the non-chemical alternatives to controlling it. Pesticides should be a last resort because they could infiltrate groundwater, possibly contaminate drinking supplies, and hurt downstream ecosystems.

The Stormwater-Friendly Lawn

The following lawn-care steps will not only help to protect local streams and rivers but also result in cost savings for homeowners:

  • Set your mower height to 3 inches or higher. Taller grass slows the runoff and produces a deeper and denser root system, which absorbs more water and prevents erosion. Deeper roots also reduce the need for watering during droughts and suppress weeds from growing up around them.
  • Keep grass clippings and chopped leaves on your property. A mulch-mower is ideal for retaining and spreading clippings on your lawn. The clippings decompose quickly, provide important nutrients for your lawn, and settle to create an organic layer on the soil that encourages stormwater infiltration. Using this mulch may also reduce or eliminate the need for nitrogen fertilizers. If mulching with your clippings is not possible, bag and store them in a compost area and then use the organic material that’s created as a fertilizer later.
  • Figure out if you really need to fertilize your lawn. Foregoing fertilizer is ideal for the health of local waterways and ecosystems. However, if your lawn is thin or has bare spots, you may not have a choice since a dense, vegetated cover is the most stormwater-friendly lawn. There are no one-size-fits-all guidelines when it comes to fertilizer. Homeowners’ needs vary drastically based on the soil texture and pH and nutrient levels. In fact, soil tests may reveal that your lawn is suffering from “micronutrient deficiency,” a problem that standard chemical fertilizers may not alleviate. Identifying your lawn’s needs first will reduce unnecessary applications, create a healthier lawn faster, and reduce your long-term costs.
  • If fertilizer is needed, maximize the benefits of slow-release nitrogen and minimize the number of chemical applications. Typically called “water insoluble nitrogen,” or WIN, on fertilizer bags, slow-release nitrogen limits nutrient runoff and exportation. This type of fertilizer should be applied to your lawn in the spring, instead of the fall, to provide a steady source of nutrients throughout the growing season. Another tip: Homeowners should wait until the grass begins growing in March to fertilize and then stop fertilizing after October. Fertilizing during a lawn’s dormant season increases the risk that the chemicals will run off into streams or leach into your water table because the root systems are less active.
  • Do not fertilize or use pesticides within 15 to 20 feet of a stream. Keeping this distance will help keep chemicals out of waterways. Also, if you live near a stream, consider establishing a natural riparian buffer there instead. To learn more about these buffers, visit and click on “Structural BMPs.” Also, when you’re done applying fertilizer, immediately sweep any granulated chemicals off hard surfaces and back onto your lawn. Your walkway, driveway, patio, or local road is often a quick route to the drainage pipes that discharge into local streams.
In the long run, little actions, such as taking a stormwater-friendly approach to your garden and lawn, will have a big impact as all of them work together to protect our water’s quality.

What is a watershed?

A watershed is the area of land that captures rain and snow, then stores, filters, seeps, or drains this water into a common waterbody (marsh, stream, river or lake). A watershed includes the network of streams that drains that surface land area and the groundwater and aquifers located underground that contribute water to those streams.

East Brandywine Township has three main subwatersheds: Beaver Creek, Culbertson Run, and East Branch Brandywine Creek. Both Beaver Creek and Culbertson Run drain into East Branch Brandywine Creek. East Branch Brandywine flows into Brandywine Creek, which is part of the larger Christina River Basin, and ultimately the Delaware Bay.