Stormwater Management


Stormwater is water originating from a rain event or snowmelt. Stormwater runoff occurs when the ground is unable to absorb all of the water. Impervious surfaces (such as buildings, driveways, parking lots, sidewalks, roads, and even compacted gravels and soils) prevent most of the runoff from infiltrating into the ground. As such, the runoff is often directed into physical drainage systems (such as catch basins), and then discharged into local rivers, streams, and other water bodies.


As the stormwater runoff flows, it picks up pollutants (such as fertilizer, oils, salt, sediment, and trash), carries them into those drainage systems, and eventually into our local water bodies. These pollutants can cause algae blooms among other aesthetic, health, and environmental issues. Unlike wastewater, stormwater runoff is often untreated or only pretreated before they are discharged into our local water bodies. Therefore, it is very important that we work as a community to keep our stormwater clean.


The Highway Department manages the Town’s storm drainage system, also known as a Municipal Separate Storm Sewer System (MS4). The Town is authorized to discharge stormwater through the Phase II National Pollutant Discharge Elimination System (NPDES) General Permit for Stormwater Discharges from Small MS4s in Massachusetts. The U.S. Environmental Protection Agency (EPA) oversees the NPDES program. To comply with the permit, the Town must follow six Minimum Control Measures (MCMs):

  • 1. Public Education & Outreach: Provide educational material about stormwater to four audiences (residents, industry, commercial, and construction). The purpose of the educational material is to provide the targeted audience information about stormwater and how their actions may impact it.
  • 2. Public Participation: Provide an opportunity for the public to participate in the Town’s Stormwater Management Program (SWMP).
  • 3. Illicit Discharge Detection and Elimination: Find and eliminate sources of non-stormwater discharges (e.g. sewage) from the storm sewer system. Part of this requirement includes development of a system wide storm sewer map:
  • 4. Management of Construction Site Runoff: Adopt an ordinance and procedures for site plan review as well as erosion and sediment control on construction sites that disturb one or more acres of land.
  • 5. Management of Post-Construction Site Runoff: Address stormwater runoff from new development and redevelopment projects that disturb one or more acres of land. The goal of this measure is to try to management stormwater where it falls and retain it on site. This control measure encourages the use of low impact design techniques and requires the retention or treatment of runoff on site using green infrastructure practices.
  • 6. Good Housekeeping in Municipal Operations: Implement good housekeeping practices in municipal operations such as vehicle maintenance, open space, buildings and infrastructure. The permit requires street sweeping twice per year, optimization of catch basin cleaning, and pollution prevention at the Highway Garage.


You can have a great lawn, save money AND protect local waterways!

Understand the chemicals you put on your lawn.

  • Never apply fertilizer or chemicals before a forecasted rainstorm. 
  • Use pesticides and fertilizers sparingly. Always follow directions and never add more than the directions call for.
  • Consider switching to slow release and natural organic fertilizers instead of typical chemical fertilizers.
  • Make sure to use fertilizer with no or low phosphorus, as phosphorus encourages algae growth in local waterways.
  • If granules land on impervious surfaces (driveway, sidewalk, etc.) during application, be sure to sweep them up.

Be smart about irrigation.

  • Hire a Water Sense Certified Landscape Irrigation Professional to review your system at the beginning of each irrigation season.  This will help maximize the efficiency of your system, reducing your water consumption and saving you money.
  • Avoid over-watering to prevent excess runoff.  A lawn needs just 1" of water per week to be green. Be sure to check weather reports.
  • Upgrade to a moisture sensor to ensure irrigating only when needed, and avoid using old-fashioned irrigation timers.
  • Don't irrigate in the middle of the day or when it’s windy, in order to prevent evaporation and runoff.
  • Make sure that sprinkler heads are pointed at the lawn and not the pavement - adjust and fix heads as necessary.

Think about hardscapes - walkways, patios, and driveways. 

  • Traditional asphalt and concrete contribute to stormwater runoff by preventing water from soaking into the ground.  Rain water flows over these impervious surfaces, collects pollutants along the way, and flows into storm drains and streams.
  • Use permeable materials such as pavers, bricks, crushed stone, and mulch when building walkways, patios, and driveways. Permeable materials allow rain and snow melt to soak through them, thereby decreasing stormwater runoff and allowing the ground to help filter out pollutants.

Know where your runoff is going. 

  • Place a rain barrel under your downspout to easily capture rain for use around your property. A one inch rainfall on a 1,000 square foot roof yields approximately 600 gallons of water.
  • Redirect downspouts so that water flows into grass or shrubs instead of onto a driveway or sidewalk.
  • Install a dry well in your yard to capture excess runoff.

Build a rain garden.

  • Rain gardens and grassy swales are specially designed areas planted with native plants that provide a place for runoff from parking areas, driveways, walkways and roofs to collect and slowly filter into the soil, rather than flow directly into storm drains, ponds or lakes.
  • Vegetated filter strips are areas of native grass or plants created along roadways or streams. They trap the pollutants stormwater picks up as it flows across driveways and streets.

Always pick up after your dog.

  • Bacteria from dog waste can runoff into local waterways, adversely affecting drinking water supplies and recreational opportunities, such as swimming, fishing, and boating.
  • Deliberately leaving pet waste on the ground is not only unpleasant and unhealthy, it is often punishable by fines. Always pick up the waste and dispose of it in a trash can. 

Be a good steward of yard waste.

  • Don’t leave yard waste in the street or sweep it into storm drains or streams.  Either bag it up for town pickup, take it to your local landfill, or re-use it as compost.
  • Use the mulch setting on your mower to leave grass clippings in place. This will allow the nutrients in the clippings to be recycled, lowering your need for expensive fertilizer.
  • Set your mower to leave the grass taller. This will lower the amount of clippings while also causing less stress to your grass.
  • Never dump leaves in wetlands or waterways (it's harmful and illegal)
  • Create a compost pile with your yard waste and use the nutrient rich humus in your gardens or potted plants.
  • Use grass clippings or shredded leaves as mulch around shrubs and trees.  Mulch helps to suppress weeds and retain moisture. Mulch also contributes nutrients to the soil by gradually breaking down over time.  
  • Cover piles of dirt or mulch being used in landscaping projects to avoid runoff.
  • Make sure your lawn service is properly disposing of all your waste.
  • Learn more about how yard waste pollutes waterways.

Business owners and residents can do their part to keep Massachusetts' waterways clean.

For more information regarding tips of business owners and residents click on the link: