Since the 1970s, new land developments have often included stormwater basins to address increases in water runoff caused by impervious surfaces such as driveways, sidewalks, and buildings. Detention basins are designed to drain excess water, while retention basins keep water on site in a permanent pool. Both are designed to capture storm runoff and slow its flow to streams and rivers. While these basins are proven to be effective in reducing flow rates and filtering some impurities from the water, they are usually planted with shallow-rooted turf grasses, which lack the capacity for further filtering and provide minimal habitat for birds and wildlife. Detention basins can be enhanced by planting their edges with trees, shrubs, wildflowers, and longer grasses, which can improve water quality by filtering stormwater pollutants such as pesticides, motor vehicle fluids, and pet waste, while providing wildlife habitat and recreational opportunities.
How can detention basins benefit birds and the environment?
In the natural world, water from rainstorms is trapped by the leaves and roots of plants, allowing water to seep into the spongy earth, where nutrients and impurities are filtered out. Basins planted with a diversity of appropriate native plants can naturally filter out toxins that may otherwise end up in nearby rivers. In addition, many songbird species may inhabit a well-planted basin, using it as they would a natural wetland: establishing territories, building nests, and finding food and protective cover. Waterfowl such as ducks and grebes may also take up residence. Herons and egrets will also visit if fish and amphibians become established. Tall vegetation planted around the edge of the basin will discourage Canada Geese, which prefer short grasses.
Getting Started: What You Can Do
- Duplicate nature's complex stormwater management process by planting native grasses, wildflowers, and shrubs.
- Educate others as to the benefits of such plantings and teach them about the potential of storm basins.
- Do not put grass clippings, leaves, or trash in or near a stormwater basin.
- Form a homeowner's conservation group to inform others and to propose a stormwater plan for the community.
- Highlight the potential recreational opportunities of a naturally designed detention basin, such as fishing, wildlife watching, and nature walks.