A stone diaphragm intercepts, captures, and directs stormwater runoff from the hillside and parking lot to a rain garden that slows, filters, and absorbs the runoff.
Community installs new stormwater best management practice that reduces stormwater runoff, erosion, and flooding.
Communities all across the Chesapeake Bay watershed face stormwater-related issues that range from poor drainage to flooding. The Greenbelt Homes, Inc. (GHI) community in Prince George’s County, Maryland, is no exception. GHI is a housing cooperative comprising of 1,600 homes built in the 1930s and 1940s. In the last 70 years, the surrounding area’s topography has significantly changed, with a dramatic increase in the amount of impervious surfaces created due to urban development. Impervious surfaces, such as pavement and roofs, do not allow water to infiltrate into the ground, resulting in large volumes of stormwater runoff that carry increased amounts of pollutants into local streams and rivers.
To help reduce stormwater runoff and pollution to our waterways, communities can implement a variety of stormwater best management practices on their property. In 2016, GHI applied for and received a grant award through the Prince George’s County Stormwater Stewardship Grant Program to install a stormwater best management practice comprised of a stone diaphragm, stone swale, and rain garden at 20 Court Ridge Road. The 20 Court Ridge housing units are located at the bottom of a hill adjacent to a large parking lot. Previously during rain events, stormwater runoff would flow freely down the hill, often causing flooding in the homes’ crawlspaces, walkways, and common areas. After the installation of the new system, completed earlier this year, the GHI community has noticed significant improvements. Now, the stone diaphragm prevents stormwater runoff from flowing directly to the housing units by intercepting and capturing the runoff. The stone diaphragm carries the runoff downhill, then through underground pipes across the parking lot, and finally into a stone swale and rain garden. The rain garden slows, captures, and filters stormwater runoff using plants and soil mixes that mimic natural filtering processes that remove pollutants. The rain garden features a variety of native plants, such as butterfly milkweed and beardtongue, that are adapted to local site conditions, and therefore require less maintenance, watering, and fertilizer. In addition, native plants attract pollinators and other wildlife, such as butterflies and birds, to the rain garden, resulting in a beautiful outdoor space for residents to enjoy.
Congrats to GHI for the successful implementation of their first major stormwater best management practice and for their commitment to improving our waterways!
This project was funded by the Prince George’s County Stormwater Stewardship Grant Program, a partnership between the Trust and the County, which aims to improve water quality in the County’s waterways, improve communities, and engage County residents in the issues associated with stormwater runoff pollution.
The Prince George’s Stormwater Stewardship Grant Program is currently open and accepting applications.