The eroding slope outside of the UMaine Extension water quality office has been stabilized with shrubs, perennials, and groundcover flanking a curved path. The rain garden in the foreground captures and filters polluted storm water runoff from the parking lot.  Photo courtesy of Maine Cooperative Extension.

Extension Publication: Rain Gardens Filter Runoff

University of Maine Cooperative Extension has a new bulletin, “Adding a Rain Garden to Your Landscape,” the newest offering in its Landscapes for Maine series. The eight-page bulletin is available for $1.50 through Extension’s books and publications Web site at www.umext.maine.edu, or by calling 207-581-3792.

Developed by UMaine Extension assistant scientist Laura Wilson and water resource specialist Mary Gilbertson of the Portland Water District, the publication details how to plan for, design, install and maintain a rain garden on your property, and includes garden designs and plant lists. Rain gardens help protect the water quality in our lakes, streams and rivers by reducing polluted runoff.

According to Wilson, “research shows that rain gardens are remarkably effective at treating phosphorus from storm water runoff – on an individual or larger commercial scale. Rain gardens are also fairly easy to install and even easier to maintain, and they're pretty, too.”

Wilson herself installed a rain garden to filter storm water runoff from the parking area outside her office at the University of Maine, which overlooks the Stillwater River. The hard, paved surface sheds rain water, which then carries phosphorous and surface contaminants toward the river. To remedy the situation, Wilson, landscape designer Kirsten Reberg-Horton and volunteers planted trees, shrubs, perennials and groundcover to stabilize the eroding slope next to the parking lot. Then they installed a rock-lined trench to direct runoff from the parking lot, and a rain garden to capture and infiltrate the water.

The public is welcome to visit the demonstration rain garden at 495 College Avenue in Orono, and details of the project are at www.umaine.edu/waterquality/landscapes.htm. Wilson can be contacted at Laura Wilson 207-581-2971, lwilson@umext.maine.edu