A rain garden is a simple, beautiful and functional way to improve the landscape and improve local water quality.

Up to 70% of the pollution in our surface waters comes from stormwater. Rainfall runs off roofs, roads and lawns, washing away accumulations of sediment and other pollutants such as fertilizers, pesticides and motor oil, which are then carried to the nearest stream.

A rain garden is constructed on a low spot below a grass-covered area over which stormwater run-off tends to flow. It can hold water for up to 48 hours, giving it a chance to seep naturally into the ground. Water that is captured by a raingarden is filtered by mulch and soil, taken up by plants , cleaned of many pollutants and is added to the groundwater supply.

How do you build a rain garden?
For a small residential "backyard" type of installation.

Step #2: Add a Layer of Sand
Fill the bottom of the hole with a layer of sand one foot deep at the bottom. This reservoir will hold water long enough to slowly percolate into the ground.

Step #4: Add some Native Plants
Plant attractive native groundcover, shrubs and trees which thrive on excess nutrients that are harmful to surface waters, and provide habitat for local wildlife.

Step #5: Cover with a layer of mulch
Covering the garden with four to six inches of mulch absorbs water and keeps it moist during dry periods.

How does a rain garden handle runoff?

Filtration
Mulch, organic soil and sand filter out particles of pollution as stormwater percolates through the layers of a raingarden.

Nutrient Uptake
The nutrients found in fertilizers and pet waste are a major source of pollution in local waters and in the Chesapeake Bay. The plants in the rain garden remove nutrients from water.

Pollutant Breakdown
Bacteria and Fungi found in mulch and soil have the ability to break down many pollutants including the hydrocarbons in oil and gas.

Groundwater Recharge
The water that is processed by a rain garden gradually percolates into the surrounding soil and has the opportunity to infiltrate through layers of soil down to the water table below. Recharging the groundwater provides water for wells and surface water such as ponds and streams.

For more information about rain gardens and stormwater management,
check out the following web sites:

Rain Garden Plants