Why Do It

rainbarrel.jpgA rain barrel prevents stormwater pollution in several ways. It slows down roof runoff, which protects streams from erosion and reduces flooding. If you are in a combined sewer overflow (CSO) area, it reduces sewage discharges into streams and bays during heavy rains. Rain barrels can provide water for lawns, gardens, and houseplants, and can lower your water bill.

In South Portland, rain barrels are considered a voluntary measure home or business owners may take to protect the environment.


Basic Features

A rain barrel is a storage container connected to a gutter or downspout that temporarily stores rain water for slow release into a lawn or garden. The water can also be used for a garden or house plants through a spigot.

  • To be effective and safe, a rain barrel has these features:
  • A sturdy and level base to rest on (50 gallons of water weighs over 400 pounds). Raising the rain barrel allows easier draining.
  • A mesh screen at the top which allows water in, but keeps debris and insects out.
  • A soaker hose and/or a spigot to let water out. A rain barrel does not provide any stormwater benefit if left full. Also, completely draining the barrel will eliminate mosquito habitat. A low maintenance approach is to attach a soaker hose which automatically drains the barrel over about 24 hours.
  • You may need to trim or extend your downspout to meet the rain barrel.
  • Rain barrels should be removed (or disconnected, turned upside down, etc.) during the winter. Ice will damage the barrel.

Design and Installation

Many homeowners can install a rain barrel themselves, or a local contractor can do it. There are companies that specialize in rain harvesting equipment and installations, as well. See these online resources :

  • Portland Water District Rain Barrel Fact Sheet http://www.pwd.org/pdf/water_resources/conservation fact sheets/rain_barrels.pdf
  • Maryland Environmental Design: Build a Rain Barrel http://www.dnr.state.md.us/ed/rainbarrel.html
  • Center for Watershed Protection: How to Build and Install a Rain Barrel  http://www.cwp.org/images/stories/RainBarrelGarden.pdf


Ensure your rain barrel empties 24 to 48 hours after a storm. The barrel needs to be empty when it rains to provide a stormwater benefit.

Empty and remove (or disconnect) your rain barrel during the winter, as ice will damage it.