“We can all help minimize the problem of storm water runoff by planting rain gardens — 6 to 12-inch-deep depressions filled with native plants. …The square footage of your rain garden should generally be about 20 percent that of the area draining into it. For example, if your roof covers 800 square feet, a rain garden designed to collect all of the roof’s runoff should cover 160 square feet. To capture runoff most efficiently, a rain garden should be longer than it is wide, and aligned perpendicular to the slope.” – from the Greentips April 2009 online newsletter of the Union of Concerned Scientists. Also see Surfrider’s Ocean Friendly Gardens web section.