December 24, 2012
Winter rain and spring snowmelt wash pollution from hard surfaces into streams, rivers and Puget Sound and threaten some areas with flooding. Property owners can reduce flooding risk, non-point source pollution and visually enhance the landscape by installing rain gardens.
In commercial property development rain gardens are less expensive and more effective than ground vault systems. Rain gardens can be designed to fit even small lots and accommodate a wide variety of plants.
Washington State University has published a "Rain Garden Handbook for Western Washington Homeowners that provides step-by-step instructions for locating, designing, building and maintaining rain gardens. It includes important guidelines for how to select a site and what not to do. For example it says do not locate a rain garden "within 10 feet of a building foundation to avoid water getting into basements and crawl spaces."
Soil drainage testing, proper sizing for the amount of run off, types site preparation and plant selection, cost estimates and a list of information resources is also included.