Residents of the District can get an audit of their property’s storm-water runoff and advice on how to reduce it under the District Department of Environment’s RiverSmart program.

The program was launched citywide two years ago, said Leah Lemoine, one of three auditors who have to date advised 1,800 residents on how to capture the rain from roofs, pavement and other impervious surfaces. In a heavy, 1.25-inch rainfall, a 1,000-square-foot roof generates 748 gallons of water, according to experts.

Under the RiverSmart Homes program, the department, in a grant program with the Alliance for the Chesapeake Bay, helps residents install rain gardens or the more passive conservation landscape of native plants, as well as rain barrels. It also subsidizes the planting of trees and the installation of pervious paving.

The rain garden is worth $1,200, but the homeowner pays $75. The charge for the conservation landscape, which the department calls BayScaping, is $100. Homeowners also pay part of the costs of a rain barrel ($30).

Downspouts can also feed directly into rain barrels or their larger cousins, cisterns. This water can be used to water other garden beds. (Julie Notarianni/For The Washington Post)

DC Water and the department are working on a plan to reduce the current storm-water surcharges on water bills to residents who have installed the measures. Call 202-535-2252. The Web site is

Montgomery County also has an active rain garden program, called RainScapes. Residents can get a rebate up to $1,200 for rain gardens. Details are on the Department of Environmental Protection’s Web site at www.montgomery

Some other local jurisdictions are considering similar programs. Several how-to manuals have been developed on the Web, including ones by the Northern Virginia Soil and Water Conservation District, the University of Wisconsin and Rutgers University.

Adrian Higgins

Chat live: Adrian Higgins will take your questions about rain gardens and other gardening topics at 1 p.m. Thursday. Submit your questions now.

Video: In the latest installment of his video series on his community garden plot, Adrian Higgins takes stock of the growing season. Check it out here.