Capturing rainwater and preventing runoff

Permeable paversWhen it rains, water can’t soak into impervious surfaces like rooftops, driveways, and roads. Instead, it runs off into streets and storm sewers creating stormwater. From our streets to our streams, stormwater picks up nutrients, dirt, salt, fertilizers, pesticides, oil, bacteria, and garbage.

Reducing runoff is critical to minimizing the impact our yards and gardens have on the surrounding lakes and streams. There are many ways to encourage rainwater to soak into the ground. Or you can capture rainwater for use in your yard. Either way, stormwater is reduced and our lakes and rivers stay clean.

Permeable surfaces: Let it soak in

Rain will soak in to ground where there are gardens and other vegetation. These surfaces are permeable, meaning they let the water through. Rain will not soak through your roof, most driveways, or roads. These surfaces are impermeable.

When you are planning changes to your house or lot, think about reducing the size of hard surfaces. For areas where hard surfaces are necessary, consider pavers or pavement that lets water through. There are now a variety of permeable pavements on the market that are specifically designed to increase infiltration into the ground. Ask your contractor or home and garden supply store for water-friendly pavers, or porous pavement or asphalt.

Rain gardens and native plants: Beautiful solutions to water pollution

A rain garden is a popular landscaping choice that prevents water pollution by allowing stormwater to soak into the ground before it runs off. Rain gardens and native plants also:

  • Prevent erosion by holding soil in place with their deep roots.
  • Attract birds and butterflies.
  • Require little watering and maintenance once established.

Rain gardens are concave gardens that collect runoff from downspouts or driveways. Plants that tolerate "wet feet" should be planted in the bottom, while plants that need less water are planted on the edges.

Rain barrels

Rain barrel for collecting rain off your roofAnother way to reduce runoff is to capture some of it with rain barrels. Rain barrels also help conserve water. They can be fancy or simple, but the basic structure is to have a barrel at the end of a downspout. The barrel has a spigot or hose that you can use to water your garden or yard. Several home improvement stores now sell rain barrels.

In Minnesota, rain barrels will need to be disconnected during winter so that they don't freeze and crack. To winterize your rain barrel:

  1. Disconnect the downspout from the rain barrel and re-connect a downspout extension to the main downspout to funnel water away from the foundation of the house.
  2. Empty the rain barrel.
  3. Flip the rain barrel upside-down and store it outside, or, if you have room, move the rain barrel into a garage or basement.

Green roofs

Another way to reduce runoff and the amount of impervious surfaces on your property is with a green roof. A green, or vegetated, roof usually contains a liner, insulation, drainage system, planting medium, and drought-tolerant, low-maintenance plants. Green roofs can reduce the costs associated with roof replacement, energy, stormwater management, the effect of the urban heat island, and improve air quality.

Watch a webcast on Stormwater as an Asset: Rain Harvesting Tips for Homeowners. This one-hour presentation focuses on how and when to use rain gardens, rain barrels, and pervious pavers.

Check out the Minnesota Green Roofs Council for additional green roof resources.

Check out our green building information.