Rein in Runoff with Rain Gardens

A rain garden class at the East Providence library
 taught landscapers of all experience levels how
to both cut water pollution and beautify the yard.
 (Tim Faulkner/ecoRI News)

Tom's note: I am on the South County Advisory Committee for Save The Bay and one of our objectives is raising awareness of the advantages of rain gardens. There is a fine demonstration rain garden in Wilcox Park in Westerly.

By TIM FAULKNER/ecoRI News staff

A 1,000-square-foot roof produces about 600 gallons of water from an inch of rain. A rain garden can reduce such runoff -- and the harmful pollutants it collects -- from flowing into local waterways.

The concept is simple: Keep rain and the pollutants it carries out of storm drains with a rain garden.

"The point is to show you how easy this is to do," said Kate Venturini, an instructor with the the University of Rhode Island's Stormwater Solutions Project, during a recent hand-ons landscaping workshop at the East Providence Public Library.

A rain garden is a shallow-planted area designed to soak up runoff from roofs, driveways, lawns and parking lots. During heavy rains in particular, these planted gardens reduce the stream of water — and the harmful pollutants it collects — from flowing down streets and into local waterways.

Currently, about 12 percent of Rhode Island is covered by impervious surfaces such as asphalt, cement and roofing.

These gardens allow concentrations of nitrogen and phosphorous to absorb and dissipate in soil instead of harming aquatic ecosystems and contaminating drinking water supplies. Other common pollutants washed down street drains include nitrogen oxide from car exhaust, rubber particles from tires, metal from wearing brakes, spilled antifreeze and lawn fertilizer.

The volume of runoff from even a small area can be huge. A 1,000-square-foot roof produces about 600 gallons of water from an inch of rain, Venturini said.

After a morning of instruction about different soil types and ideal vegetation for rain gardens, the class of 40 landscapers, landscape architects and educators dug in the dirt. By late afternoon, the class had built two new rain gardens for the city, which in turn provided garden tools, compost and plants such as elderberry, sweet pepper bush, low-bush blueberry and columbine for the project.

Ways to reduce runoff and recycle water at home include:

Rain barrels are perfect for capturing rain water and then using that water on your gardens. It saves water and lowers your water bill.

Grid pavers and other porous materials are great alternatives to asphalt and cement driveways and patios.

Downspout extenders help divert rain to a landscaped area or garden and away from paved areas and even open lawn, which are not the best spots to catch runoff from a downspout.

The East Providence Public Library program was the second of three training classes about residential rain gardens held across the state. A third session will be held later this year in Providence. The class is open to landscape professionals and the general public. Look for program details here.

Republished with permission from ecoRI News. The original article is available here.