Community Action Steps
- Minimize impervious surfaces on your property. In nature, most precipitation soaks into the ground where it falls. Plants absorb much of this through their roots, and some makes its way down to the water table, being purified as it gradually percolates through the soil. The “built environment” however, is characterized by impervious surfaces (surfaces that don’t absorb water), so that a large portion of rainfall or snow melt becomes stormwater runoff. Reducing the amount of impervious surface on your property therefore reduces the amount of runoff.
- Replace lawn areas with native plants. Lawns aren’t particularly effective at absorbing and retaining water, especially during heavy rains. This is a problem not only because more natural precipitation runs off them, but also because they may require a lot of irrigation, which in turn can create even more runoff. Native plants, such as shrubs and wildflowers, tend to develop more extensive root systems that take in and hold water much better than lawns. As an added bonus, they require less maintenance than a lawn does.
- Don’t leave soil exposed. Depending on your slope and soil type, bare soil can be nearly as impervious as concrete. If you can’t or don’t wish to plant vegetation on an exposed patch of soil, cover it with mulch, wood chips, or gravel. This is especially important for newly landscaped yards that don’t yet have established vegetation.
- Plant trees and preserve existing ones. Trees’ immense root systems effectively absorb water over a large area. In addition, the canopy of a tree slows the fall of rainwater so that the ground is capable of absorbing larger amounts than it otherwise would be. Plant native trees or trees which take in a lot of water and are well adapted to your environment, and take care of your existing trees. For new home constructions, leave trees in place if possible.
- Create a rain garden. A rain garden is a garden, planted in a slight depression in the ground that collects water and allows it to gradually permeate into the soil. Rain gardens come in many sizes and are typically planted at the base of a slope or even at the outlet to a downspout–anywhere where water naturally flows or can be directed. Water-loving plants and a base of permeable soil enhanced with fertile loam and a topcoat of mulch allow the rain garden to quickly absorb even large amounts of water, usually in just a few hours.
- Install berms and vegetated swales. A berm is a slightly raised area, while a swale is ditch with a mild slope. Berms can be used to slow runoff on steep slopes, and swales planted with grass or other plants can direct water to a rain garden. Swales can also direct water toward a storm drain or street: since they significantly reduce the amount of runoff, very little water that enters a vegetated swale will actually make it to the street or drain.
- Use the water that drains off your roof. A 1,000 square foot roof can produce more than 600 gallons of runoff for every 1″ of rain that falls on it. If your downspouts are connected directly to a storm drain, disconnecting them is the single most important step you can take to reduce runoff. Instead of allowing water to go directly into the sewer or to run into the street, direct your downspouts toward a vegetated area, such as your garden or lawn. Use extensions to ensure the water comes out at least 5 feet away from your foundation. Alternatively, install rain barrels or cisterns to collect the water so you can reduce the risk of soggy yards or basement flooding and save some rain for a sunny day.