Managing Stormwater Runoff: A Green Infrastructure Approach
by Lynn Richards

and

Taking Low Impact Development from Research to Regulations
by John S. Rozum, AICP, and David W. Dickson

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The practice of stormwater management is evolving beyond engineered approaches applied at the site level to an approach that looks at managing stormwater in more natural ways. "Green infrastructure" and "low impact development" techniques can be better for the environment and cost-effective. But before they can be implemented, changes to local land development policies and regulations may be needed.

From PCJ #73, Winter 2009
This article is also available as part of our Green Essentials reprint collection
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a bioswale in a new North Charleston development
A bioswale is one of several "low impact" features designed to manage stormwater in a North Charleston, S.C., development.

Read first few paragraphs of Lynn Richards article:

Increasingly, communities are looking for ways to maximize the opportunities and benefits associated with growth while minimizing and managing its negative environmental impacts, especially in terms of stormwater runoff. In many places, however, stormwater management is still primarily dealt with only at the site development level using "end-of-pipe" practices, such as detention ponds or conveyance systems, such as sewer systems or culverts. These practices, however, fail to address cumulative water quality impacts from the excessive amounts of impervious cover associated with land development.

While conventional stormwater approaches work to drain each site, the continued spread of development in many areas has resulted in too much water, carrying too much pollution, running into drains and receiving water bodies. This can reduce water quality, especially at drain outlets, and lead to a dramatic drop in the refill rate of aquifers and streams.

Today, the practice of stormwater management is evolving beyond engineered approaches applied at the site level to an approach that looks at managing stormwater through more natural approaches. These "green infrastructure" approaches can be better for the environment and cost-effective. Green infrastructure strategies reduce and locally manage stormwater through infiltration (water soaking into the ground), capture and reuse (water being stored in a rain barrel or cistern for later use in watering plants or flushing toilets), and evapotranspiration (water being used by trees and plants).

A comprehensive green infrastructure approach to stormwater management seeks to:

  • Preserve and enhance natural features, such as undisturbed forests, meadows, wetlands, regional and neighborhood greenways, trails, and other natural areas.
  • Recycle land by directing new development to already degraded land, such as parking lots, vacant buildings, and abandoned malls.
  • Reduce land consumption and development footprint by using land more efficiently.
  • Reuse stormwater by directing it back into the ground through infiltration, evapotranspiration, or through capture and reuse techniques.

    While traditional approaches to stormwater management have focused at site-level techniques, green infrastructure takes into account the wide range of development-related issues at the regional, neighborhood, and site-level that affect impervious cover and stormwater runoff. ...

    Read first few paragraphs of John Rozum & David Dickson article:

    As anyone involved in land use knows, a new subdivision rarely garners much emotion, particularly of the positive variety. So it was surprising when while on a tour of the new Glenbrook Green subdivision in 2006 Connecticut's chief environmental official exclaimed, "this subdivision is wicked cool!" The 29-lot Waterford, Connecticut subdivision, also known as the Jordan Cove project, is one of the country's premier applied research sites for a variety of stormwater management and site design approaches often referred to as Low Impact Development (LID). However, making "wicked cool" subdivisions like Jordan Cove commonplace will require a multi-pronged, yet doable, revision of local land use regulations.

    A "New" Approach to Stormwater

    We know from countless studies that current stormwater management practices are not doing a great job of protecting water quality. Increasingly, communities are recognizing the need to manage stormwater through an integrative, comprehensive approach to land use planning and site design. LID refers to a variety of land use practices, including rain gardens, vegetated swales, pervious pavements, green roofs, and others, that seek to maintain or even improve the pre-development hydrology (i.e., quality and quantity of runoff) of a particular development site. LID practices have been highly touted throughout the country in recent years as one large piece of this puzzle.

    Research findings suggest it is worth the hype. The Jordan Cove project (see next page), funded by the EPA through the state's Department of Environmental Protection (DEP), represented a ten-year research effort to gauge the effectiveness of many of these onsite stormwater management techniques in "real world" conditions. The project found that when used in combination these practices can indeed replicate or improve the pre-development hydrology of an area. Yet, implementing these practices will require communities to make changes to the way that land development is done from top to bottom and changes of this magnitude are rarely taken quickly. ...

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