July 14, 2014

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Geosyntec Part of Winning Team for Chattanooga LID Design Competition

A team of Geosyntec engineers, in partnership with local landscape architects, contributed to a winning entry in a low-impact development (LID) design competition sponsored this spring and summer by the City of Chattanooga and other regional partners in Tennessee.

As part of the Resource: Rain LID Design Challenge, the team earned a first-place award for "Streamline Broad Street," an urban redevelopment design that re-imagines the Chattanooga Broad Street corridor leading from the Tennessee Aquarium through Downtown Chattanooga to Martin Luther King Boulevard.

During the past year, Chattanooga officials developed new stormwater runoff reduction standards for watersheds throughout the city. The LID Design Challenge sought to advance innovative, cost-effective, sustainable designs for four different neighborhoods that could serve as inspiring, regional models for watershed protection and community revitalization.

Keil Neff, Ph.D., P.E., a civil and environmental engineer for Geosyntec based in Tennessee, and Charlene Harper, P.E., LEED AP, a water resources engineer for the firm based in Virginia, developed a contest entry in partnership with W.M. Whitaker and Associates Landscape Architects of Lookout Mountain, Georgia, and Garth Brown Designs of Chattanooga.

In addition, Geosyntec engineers Brandon Klenzendorf (Austin) and Ken Swinson (Knoxville) provided hydrologic modeling and GIS support for the design contest, and Sarah Fick (Chattanooga) and Katie Fox (Pensacola) provided research assistance.

"We gave the city a very flexible schematic design demonstrating two design goals — the runoff reduction benefits of maximizing LID within the right-of-way, as well as the costs and results of using LID to simply comply with their new minimum standards," Ms. Harper said.

The team's contest entry featured multiple elements of green infrastructure, including permeable parking stalls and bike lanes as well as integrated micro-bioretention cells that could be installed in the future along the Broad Street corridor. The design also provided complete street concepts to accommodate multiple modes of transportation through the area.

"This innovative design, which utilized advanced hydrologic modeling to optimize the capacity of LID features, can treat runoff and reduce combined sewer overflows cost effectively while providing social and economic benefits throughout the Broad Street corridor," Dr. Neff said.

In preparing the design, the Geosyntec team used stormwater management modeling software (PCSWMM) to consider the hydrology of existing conditions and alternative scenarios for Broad Street. Computer models were used to consider how the final design might control and potentially treat stormwater along the urban corridor by exceeding the city's 1-inch "stay on volume" requirement. Separation from the city's combined sewer overflow system and the economic evaluation of LID versus conventional stormwater management practices were also considered as part of the proposed design.

For more information, contact Keil Neff in Knoxville at 865-291-4689 or This email address is being protected from spambots. You need JavaScript enabled to view it. or Charlene Harper in Richmond at 804-665-2815 or This email address is being protected from spambots. You need JavaScript enabled to view it..