Parking lot bioswales, like the one pictured above, function to landscape, shade cars, and treat and convey stormwater.
The Ecology of Development
Gaining Momentum

Bioswales. Green roofs. Porous pavement.

Terms like these, once reserved for academicians and Green Party candidates, are seeping into the lexicon of the development community as a movement toward conservation design and low impact development takes root across the country.

Locally, the Douglas County Board of Commissioners recently adopted a comprehensive development plan and zoning regulations that champion conservation design and low impact development. “Simply put, these practices fit the development to the land rather than fitting the land to the development,” said Kent Holm, director of Douglas County Environmental Services. 

In Douglas County outside municipal jurisdictions, all new subdivisions and other development now must employ conservation design as well as the use of low impact development techniques to manage stormwater. Taken together, these practices:
  • Protect valuable natural features and open space while minimizing changes to the natural hydrologic cycle;
  • Manage rain where it falls through the use of small and distributed landscape features;
  • Treat water as a valuable resource rather than a waste product to get rid of as quickly as possible; and
  • Provide engineered solutions to deal with stormwater regulations and other related scenarios.

Bioswales, for example, are landscape elements designed to remove silt and pollution from surface runoff water. This is accomplished through the creation of a drainage course with gently sloped sides that is lined with vegetation or other materials. Green roofs are the roofs of buildings that are partially or completely covered with soil and planted with vegetation, all over a waterproofing membrane. Porous pavement allows rainwater to penetrate its surface rather than run off it untreated. The water can then be detained beneath the pavement and allowed to infiltrate or be routed through a drainage structure for further treatment. 

When applied to commercial/mixed use and residential developments, these techniques can do more than meet zoning requirements and improve environmental aesthetics. They can, in some cases, create cost savings.

Green roofs, like the one pictured above, help with insulation, climate control and retention of storm runoff.
At the site level, Holm noted, significant cost savings can result from the clustering of building sites, including costs for clearing and grading, stormwater and transportation infrastructure, and facilities. In addition, better site design can reduce paving costs. “While conventional paving materials are less expensive than conservation alternatives, porous materials can help total development costs go down – sometimes as much as 30 percent – by reducing conveyance and detention needs,” Holm said.

Although green roofs are currently more expensive to install than standard roofs, the costs are highly variable and going down, Holm noted. They also have significant advantages when considering the life-cycle costs of a building project.

“Low impact development is not the answer to every issue, but it’s part of the toolbox that can be used to address development and stormwater management issues,” Holm said.

Local public efforts on the “green” development front are being bolstered by related efforts in the private sector. 

Earlier this year, Lamp, Rynearson & Associates Inc. partnered with a group of organizations, including Omaha by Design, to host a one-day workshop on stream restoration. The event examined stream issues in Omaha, the dynamics of how streams flow and change over time, and the economics of addressing these and related issues. 

The South Papillion Creek, the Big Papillion Creek and Cole Creek were explored in hands-on sessions. Cole Creek, in particular, is suffering from erosion, and its growing state of instability makes it prone to flooding.

“Erosion of our streams is more dramatic and has a greater impact than anywhere else in the country,” said Mike McMeekin, president and chairman of the board of directors of Lamp, Rynearson & Associates. “As Omaha grows, it’s important to preserve and stabilize our streams while capitalizing upon them as cultural and recreational amenities. As a result, they can become a more integral component of our city’s infrastructure.”

For more information about conservation design and low impact development efforts in Douglas County, visit http://www.dcplanning.org. For more information about the sustainable design activities of Lamp, Rynearson & Associates, visit http://lra-inc.com/sustainable_design.htm.


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