Stormwater Management

What is Stormwater?

Stormwater is excess rain that does not soak into the ground.  You can see it in the gutter of the street during a rain storm.  In densely developed areas, like Watertown, stormwater is typically collected in catch basins and manholes and then piped downstream to the Charles River.

Unlike some other nearby communities, Watertown has separate sewer No Dumping Signand stormwater drainage systems. The drain pipes do not go to Deer Island to be treated like sewage from your house is. Instead stormwater drainage is collected through catch basins, conveyed through drainage pipes, and then discharged into the Charles River, all with little to no treatment.

As stormwater flows through our yards and streets on the way to the river, it can collect pollutants that harm human health and our fragile ecosystems.  Examples of pollutants that stormwater can transport include:  fertilizers containing harmful nutrients, oil, grease, viruses, bacteria, toxic metals, sediment, and salts.

Learn more about the Charles River and some of our challenges at the EPA web-page.

View the Watertown "Rain Drain Pain" Flyer (PDF).

Stormwater Pollution video screenshot Opens in new window

Watch this video: Low-impact Development and Stormwater Pollution.

Town Stormwater Infrastructure

  1. Catch Basins
  2. Street Sweeping
  3. Drainage Pipes
  4. Outfalls
  5. Green Infrastructure

What is a Catch Basin?

There are over 3,200 catch basins in Watertown!

A catch basin, which is also known as a storm drain inlet or curb inlet, is a structure with an opening into the storm drain system. They include a grate or curb inlet at street level where stormwater enters the catch basin. But not just stormwater can enter the inlet. Oil and grease, car washing, pet waste, and any number of things can enter through the grate.

Catch basins do provide some pollution protection by preventing trash and other floatable materials from entering the drainage system. Most also contain sumps that allow larger sediments to settle in the basin. Nevertheless, catch basins provide little stormwater treatment.

Catch BasinCatch BasinCleaning Debris from Catch Basin

Cleaning collected debris from a catch basin, part of annual stormwater maintenance performed by DPW contractor.