A rain barrel collects and stores rainwater from your rooftop that would otherwise be lost to runoff and diverted to storm drains and streams. You can use water from a rain barrel to water your lawn or garden, or to wash your car.
They consist of a storage container (usually plastic), a system for diverting downspout water into the barrel, and an overflow that returns to the downspout or diverts water safely away from the house to absorb into the soil.
They should also have the following:
- Durable, rot resistant construction
- Opaque containers to discourage bacteria/algae growth
- Kid, pet, and pest-proof openings
- Valves for hose attachment
- Screens and/or filters to keep debris out of the barrel
What are they good for?
Rain barrels are good for collecting water to be used in dry summer months. If water is diverted into the yard, they work best for soils that drain well (such as the eastern metro region) rather than the west side where clay soil is hard and less absorbent.
Rain barrels are also well suited for areas that operate a combined sewer system like Portland. In Washington County, we have two separately piped systems: stormwater pipes that lead from the outside of your home to storm drains and eventually the Tualatin River and sewer pipes that carry your used wastewater directly to one of our four treatment facilities before it is released into the river. An additional benefit to our separately-piped system is our Surface & Stormwater Management (SWM) program that provides street sweeping, leaf collection and bioswales in new development that help minimize the pollution that enters our local rivers and streams.
What should you consider?
You should consider how much rain falls in on your roof. Just one inch of rain falling on a 1,000 square-foot roof produces 625 gallons of water. With an average annual rainfall of 42 inches in Oregon, you have 26,250 gallons of water falling onto your property each season. You’d therefore need to install 525 fifty-gallon barrels to contain that rain. More importantly, rain runs quickly off our hard clay soils here in Washington County and can cause flooding to you or your neighbor’s property if not piped correctly into our stormwater system.
If you do choose to install a rain barrel, remember to disconnect the barrel, and reconnect the downspout or gutter system during the winter to avoid constant overflow and ensure proper discharge during the rainiest months. Attach it in the early spring to fill it for use. Like any irrigation supply dependent on rainfall, sometimes you’ll have too much and sometimes not enough.
What better options are there?
We encourage your efforts to keep our water clean. Instead of disconnecting downspouts around your home, here are other steps you can take to protect clean water:
- Plant natives: Removing water and chemical-dependent lawns and replanting with native plants filters out pollutants and stabilizes your yard. Use a Native Plant Finder to choose plants that are right for your yard.
- Install porous pavers: Using materials for walkways and driveways that allow water to pass through reduces, slows, and cleans runoff as it makes its way to streams and wetlands. Read our Slow the Flow brochure (PDF) for more ideas.
- Monitor and mark storm drains: Since water from your yard and driveways in Washington County goes directly to nearby streams, it’s important to make sure fertilizer, soap, oil, and other waste stays out of storm drains. You can also volunteer to mark your neighborhood storm drains with the “Dump no waste, drains to river” curb markers and glue that we provide free of charge.
- Install a rain garden, stormwater planter or bioswale: Rain gardens soak up rainwater, mainly from your roof but also from your driveway and lawn. They are landscaped areas planted with native plants to replace lawn. The garden fills with a few inches of rain and lets water slowly filter into the ground rather than running off into storm drains. Learn more in the Oregon Rain Garden Guide.
- Conserve water: Before going to great lengths to collect rainwater, try using less water around the house to begin with. Take short showers, wash full loads of laundry and plant drought-tolerant plants.