Rain Garden
Let's face it. Not everyone can design for a whole neighborhood, or build a cistern platform on the side of their home. What else can the homeowner do?
With regard to our hypothetical runoff site, we have accounted only for 210 gallons per storm event which is collected in the rain barrels. Is there a way we might manage the remaining 1090 gallons AND improve the esthetic appearance of our home at the same time? You bet!
One of the most popular methods of infiltration today is a RAIN GARDEN (sometimes referred to as bioretention).This is a garden area which has been partially excavated, and filled with stone, gravel, and top soil. Depending on location and building codes, a liner may be required. These gardens can be landscaped to the owner's taste, and offer an on-site means of managing stormwater economically:
(photo credit, MDE, 2000)
Here are treatment parameters as per the California Stormwater BMP handbook
There are a number of great resources for the construction and design of these gardens, see next page: