Photo of Rain Garden from TAMU files
Rain Gardens are a beautiful way to treat the pollution from stormwater runoff before it enters our waterways. They add aesthetic value to a site, increase wildlife habitat and are a highly effective best management practice (BMP) for treating stormwater runoff. Not only do they filter off the pollutants, rain gardens also slow the flow of the water from heavy rainfalls and thus help reduce flooding in areas prone to these incidents. The benefits from incorporating rain gardens into landscape designs are numerous.
A rain garden is a shallow depression in the ground, planted with native plants that can live in a soggy environment as well as a dry environment. The depression is sculpted so storm water runs into it and gets trapped. The soil bottom of the rain garden contains different layers of materials that allow the water to drain into the surrounding soil. Once the water has been trapped in the rain garden, natural biological processes will begin to remove the nutrients from the water and break down pollutants into nutrients plants can use.
Illustration from Prince George’s County Bio-retention Manual
Rain Gardens Are More Efficient and Cost Less than Traditional Methods for Treating Stormwater before It Enters Waterways
It doesn’t always cost more to do things better and more ecologically friendly. The City of Bellingham, Washington found this out about 15 years ago when they designed a 550-square-foot section of land to catch runoff from a parking lot with 80 spaces. The rain garden was also designed to treat 91 percent of the runoff from a 50-year storm event.
Cost Comparison from the Bellingham Rain Garden
Conventional Stormwater Technique
(4,400 foot wet vault)
If you or your city is interested in exploring the possibility of using rain gardens as a way to help control stormwater runoff and pollution, we have a great resource right here in the DFW area: Our Dallas County Texas A&M Extension department. In particular we have two people associated with the Texas A&M system who are experts in stormwater management and rain garden design: Fouad Jaber, Assistant Professor and Extension Specialist; and Dotty Woodson, Extension Program Specialist.