Managing Rainwater/Stormwater Runoff: United States Environmental Protection Agency promotes a “Green Infrastructure Approach”

 

''Green'' Management of Rainwater/Stormwater Runoff Key for Long-Term Water Quality

As communities become environmentally conscious and involved, they modify and reach beyond old development-impact reduction methods to more interlinked, efficient and cost-effective strategies at site, neighborhood and regional levels, USEPA - lynn richards story (240p)writes EPA Development, Community, and Environment Division (DCED) Acting Director Lynn Richards in her ''Managing Stormwater Runoff: A Green Infrastructure Approach'' paper in the Planning Commissioners Journal (Winter 2009), calling decisions ''about where and how our towns, cities and regions grow'' the first and perhaps the most important for long-term water quality.

A comprehensive green infrastructure approach to ranwater/stormwater management, she points out, seeks to preserve and enhance natural features, including forests, meadows, wetlands, greenways, trails and similar areas; recycle land by directing development to already degraded sites, with parking lots, vacant buildings and abandoned malls; reduce land consumption and development footprints by using parcels more efficiently; and reuse rainwater/stormwater by directing it into the ground through infiltration, evapotranspiration or capture-and-reuse techniques.

 

Groundwater Recharge Capability

Citing a 2002 study by American Rivers, the National Resource Defense Council (NRDC) and Smart Growth America, which found that the nation's 20 regions with most extensive land development between 1982 and 1997 now suffer annual losses of 300 to 690 billions gallons of rainwater that would otherwise have filtered into streams and aquifers, Director Richard stresses the need for greater overall land-use efficiency to reduce impervious areas and manage rainwater runoff more effectively.

''The single most effective strategy for efficient land use is redeveloping abandoned shopping centers or underutilized parking lots rather than paving greenfield sites,'' she writes, listing several related ''green infrastructure approaches'' at the local level.

They include ''incorporating natural landscape features and functions into a neighborhood's street and road network, buildings and other developed areas; narrowing streets and roads; reducing parking requirements or establishing parking minimums; connecting open space and recreation areas; and co-locating a range of land uses (such as retail, residential, civic, and schools) to minimize impervious cover.''

 

Site-Specific Practices

Turning to ''site-specific practices aimed at maintaining natural hydrologic functions by absorbing and infiltrating precipitation where it falls,'' she recommends the use of rain gardens, green streets, bio-swales, and other infiltration arrangements, all of which ''naturally treat runoff on-site'' and help reduce the impervious surface.

As to the role planning commissions can play to make it happen, Director Richards expects them to re-examine zoning codes, subdivision regulations and other development ordinances ''for provisions that can lead to unnecessary impervious cover'' and hinder green solutions in rainwater/stormwater management.

 

Compactness and Higher Densities

Accordingly, she advises a focus on compactness and higher densities, incentives for redevelopment, tough street standards and road design guidelines, lower parking and building setback requirements, denser site coverage and optimal height limits, along with adequate landscaping and tree preservation provisions.

''A green infrastructure approach to stormwater management can provide benefits for all stakeholders: the municipality has more effective and efficient stormwater management, residents have more attractive neighborhoods, and developers have more choices on how to manage runoff,'' Director Richards concludes. ''Moreover, it can change how we think — and plan — for stormwater. With green infrastructure, stormwater is viewed not as a headache, but as an impetus for better, more environmentally oriented communities.''

 

For the complete article:

See the instructions for downloading the full text and a related article at www.plannersweb.com/articles/instructions.html. — Planning Commissioners Journal  1/26/2009

Click here to view the source article or here to view the source publication.

 

 

Posted February 2009

Acknowledgement: Smart Growth Online