A rain garden sits between a downspout and the street to prevent rainwater from reaching the storm sewer. Excavated, backfilled with free-draining soil and landscaped with a range of plants that can cope with periodic flooding, the rain garden holds water for a day or two until it can percolate into the soil. The plants also drink up some of the water.
The draining quality prevents a breeding ground for mosquitoes — the insects need a week of standing water to develop — and the rain garden also reduces the amount of metered tap water or precious well water used to keep a garden going.
The District and Montgomery County offer homeowners technical assistance and grants to install rain gardens, and other area jurisdictions are likely to follow suit as these gardens catch on.
“Homeowners are just embracing the concept,” said Leah Lemoine of the District Department of the Environment. “They love the idea of using rain gardens to help the environment.”
In the past two years, the department has used its RiverSmart program to help residents install 139 rain gardens, 176 related plantings called conservation landscapes and 1,112 rain barrels.
We visited three area homes whose owners have markedly reduced the amount of rainwater leaving their properties.
Capitol Hill
The front yard of Jamal Kadri’s rowhouse on Independence Avenue in Southeast is just 18 feet from sidewalk to front door, and his rain garden occupies about half of it. The downspout, which once tied into the city storm sewer, is now connected to a drainpipe that feeds the new garden. With family and friends, Kadri spent a day digging out the old clay soil until he had excavated 50 loads in a five-gallon bucket. He used most of the fill to form a berm next to the house to keep the water from seeping into his basement.
Kadri then backfilled the garden with sand and topsoil and a bit of rotted horse manure to populate the new garden with beneficial microbes. Two years later, the native plants in the bed are vigorous from the moisture, and include the shrubs arrowwood and sweetspire, switch grasses and the native pond iris called blue flag.
Kadri designed the garden to take two inches of rain, all but the worst storm. Only in an extreme deluge will water seep over the sidewalk, he said. In his back yard, he has diverted the rear downspout to a 130-gallon rain barrel that sits on a platform of recycled bricks. In a heavy rainfall, the excess overflows into soil beneath.
He said he spent about $300 for the plants in the front rain garden, and paid a contractor $200 to disconnect the old downspout in the rear and install a new pipe to feed the barrel.
_1337038921.jpg)
Loading...
Comments