Every home has runoff from rain and snow melt. Roof downspouts often wash driveways clean and the runoff from yards flows to streets. The runoff picks up tiny amounts of dirt, fertilizers, pesticides, grease, oil, bacteria and other contaminants. Catch basins in the street collect runoff from many homes and dump these pollutants into streams and ponds.
The runoff from a quarter acre house lot can range from 150,000 to 200,000 gallons per year. Simple, low-cost measures will put storm water into the ground and cleanse 50,000 or more gallons annually. Improvements done over several years will spread out the effort for reducing the runoff from your yard. Once installed, the clean water benefits continue year after year.
Do-It-Yourself (DIY) Runoff Solutions
Rain gardens are a very effective way to keep streams and ponds healthy. A bowl shaped rain garden will collect the runoff from a roof, driveway, parking area or yard and allow it to seep into the ground. The rain garden plants and soils filter the runoff and cleanse pollutants that could harm water quality.
Letting the runoff soak-in replaces the groundwater that keeps streams flowing during dry times. On hot summer days, rain gardens will also cool runoff by putting it into the ground. A constant supply of cool, clean groundwater is essential to the health of aquatic life.
Rain gardens are planted with flowers, shrubs, trees and grasses that are easy-to-maintain and thrive without fertilizers and pesticides. There is an array of colorful plants available at garden centers and home improvement stores, which provide food and habitat for wildlife. Rain gardens can be placed in sunny or shady locations, and will do best on well-drained soils.
The garden can be easily built in the size, shape and appearance you desire. These natural areas attract birds and beneficial insects like butterflies and bees that pollinate plants. You and your family can enjoy these mini-ecosystems that enrich your yard, as well as make your neighborhood more attractive. Download MWC's free Rain Garden Guide.
Combine rain gardens with one or more of the other measures below to further reduce home runoff.
Like a rain garden, a shallow swale can cleanse runoff from your roof or driveway. The swale is planted with grass, perennials and shrubs that can handle an occasional dunking and moist soil conditions. As runoff flows in the swale, the vegetation filters it, and allows it to soak into the ground.
- Shallow conveyance trenches up to 12 inches deep convey runoff to a rain garden or other area where it can soak into the ground.
- Deeper infiltration trenches (18 inches or more) hold a lot of water from storms in the spaces between the rocks and allow it to soak into the ground. Infiltration trenches should be 5 feet away from your property lines, and 10 feet away from any building. Grasses, flowers or shrubs can be planted over the soakage trench, or you can create a walkway above the trench.
Don’t put trenches in soggy areas (where water won’t soak in) or over major tree roots. At least 3 days before digging, call 1-800-Dig-Safe to locate any utilities.
A 5 - 10 foot wide evergreen ribbon at the edge of your yard or beside your driveway is another way to filter runoff. Groundcovers like Pachysandra or Periwinkle are an inexpensive way to allow runoff to soak into the ground. Groundcovers require little maintenance and build spongy soil under the plants. Ask your garden center or home improvement store for details about sun and soil conditions.
Additional DIY runoff remedies include:
- Rain barrels
- Porous paving for paths, walkways and patios