Parking lot ponds to act more like natural wetlands

CLEVELAND - Mulch-lined ponds at the edges of a new shopping center being built south of downtown could be a model for treating storm runoff along parking lots and roads across the state, city officials said.

When rooftops, parking lots and roadways take the place of soil, rain no longer soaks gently into the ground but rushes in torrents to drains, carrying along motor oil, antifreeze and other pollutants. Usually the water collects in ponds at the edge of lots -- designed to prevent floods, not pollution -- and drains straight to rivers and other waterways.

The parking lots at the 91-acre Steelyard Commons will slope gently toward basins designed to scrub pollutants from water by letting it pass through layers of mulch, soil and sand, much like a natural wetland. The water then drains to pipes that lead to the Cuyahoga River.

"We're breaking the train of traditional thinking in how we approach stormwater management," said Todd Houser, a stormwater specialist with the Cuyahoga County Soil and Water Conservation District. "We're changing gears. We're not just looking at it for flood control, but water quality treatment."

The mall's developer, First Interstate Properties Ltd. of Beachwood, could include the ponds in future projects after seeing how these prototypes work out, said Richard Carlisle, vice president and director of development.

Similar ponds are planned for an expansion of the Cleveland Art Museum and a trail near a local bridge.

More communities statewide could soon be watching the pond's success. The Ohio Department of Transportation in two years will require communities with state storm-water permits to make developers show how construction sites that disturb one or more acres will not pollute water with runoff.

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