Innovative designs

Development in a rapidly growing suburb has prompted innovative thinking to protect watersheds and stream ecosystems.

Matt Moore, district administrator for the South Washington Watershed District in Woodbury, Minnesota has spearheaded the Central Corridor Project, a stormwater management effort that takes advantage of the bedrock geology of the area using an ecological design.

The challenge: What to do with the stormwater runoff from all the new residential and commercial development? Rather than simply flush it straight to the Mississippi River, the Central Corridor Project would develop a network of infiltration basins through a corridor running about 14 miles from Lake Elmo Regional Park through Woodbury to Cottage Grove Ravine Regional Park and then to the Mississippi River. Matt's interest in thinking about human connections, ecological connections, and long-term water management in this new way is a major departure from the more conventional "pipe it and dump it in the river" approach.

Essentially acting as surrogate wetlands, the infiltration basins are intended to provide some of the ecosystem services that natural communities would. The basins, connected by short lengths of pipe and lift stations, would hold, filter, and retain runoff, rather than flush it in high volumes directly to the river. (See also "Water - But Not Too Much Water - for Valley Branch Creek.")

Commercial and residential properties can also use ecological design principles to treat rainfall as an amenity instead of a liability. Sometimes referred to as "low-impact development," the idea is to maintain the pre-development hydrology of the site by infiltrating, storing, filtering, evaporating, and detaining runoff. Low impact development uses tools such as rain gardens, rain barrels, bioretention basins, infiltration trenches, green roofs and porous pavements to accomplish this goal.

For more information, go online:

www.lowimpactdevelopment.org

www.lid-stormwater.net/background.htm

www.stormh20.com