Divert your roof rainwater to make a side yard marsh.
Eight years ago, Craig Tufts, NWF's Chief Naturalist, created his own stormwater marsh next to his northern Virginia home. As with any project involving significant landscape change, before beginning to excavate, Craig checked with his homeowner's association and municipal government to make sure his intended marsh project was permissible. Here are the steps he followed, which you can adapt to meet your situation:
Choosing a Site:
- Choose a site based on access to water and which is flat enough to accommodate a marsh and to hold water. Using a roof to supply water is a good idea, since gravity will work in your favor to bring water to the marsh and because the water quality tends good.
- Base your site selection on the kinds of plants you want to grow. For example, if you want to grow sun-loving plants, choose a sunny location on the south side of your home.
- A third consideration is soil type. Very sandy soil is too permeable to adequately hold water. Soil with a good deal of absorbent clay works well.
- Outline the perimeter of the proposed site.
- Strip the sod from the outlined area and excavate the subsoil and rock to about 14 inches deep, allowing for an emergency spillway (an area of turf grass at the lower end of the marsh).
- During excavation, use a level to make sure the ground is even.
- Connect a length of flexible plastic pipe to a downspout from the roof, angling it away from the house and burying it beneath the ground and into the marsh. Make sure the angle of the pipe is great enough to avoid water back-up during a big storm.
- Prepare the soil. If your soil is very clayey, work sand, compost, and other organic material into the top few inches of soil. Mimic a vegetation zone patter by varying the original basin depth and backfilling with your marsh soil.
- Choose plants that provide food and cover for wildlife.
Eight years after its creation, Craig's stormwater marsh supports 45 plant species, including Joe-pye weed, cardinal flowers, great blue lobelia, buttonbush, sweet pepperbush, spicebush, and swamp milkweed.