During periods of heavy rainfall, the city of Chattanooga, Tennessee’s sewer systems were experiencing overflows. As water ran out of underground real estate, the untreated stormwater and wastewater was discharging to nearby streams and rivers. To comply with the U.S. Environmental Protection Agency’s Combined Sewer Overflow Control Policy, the City of Chattanooga’s Waste Resources Division called on Gresham Smith to help control the overflows during periods of wet weather. Alongside LDA Engineering, we developed a Green Infrastructure Master Plan for the City to achieve compliance.
miles of combined sewers
compliance with clean water laws
combined sewer treatment facilities
Green is the New Gray in Infrastructure
Alongside LDA Engineering, we developed a Green Infrastructure Master Plan for the City of Chattanooga. Our team coordinated with a variety of city departments to identify cost-effective green infrastructure alternatives, instead of the traditional “gray” infrastructure, such as storm sewers and storage facilities, that already existed in downtown Chattanooga. In addition to identifying low-impact development methods, we also quantified the potential benefits of using native landscaping, bioretention, permeable pavements, rainfall gardens and green roofs on stormwater management projects.
The Right Tools for the Job
The plan we developed allowed city to capitalize on existing public works projects, green infrastructure initiatives and the city’s strong history of public-private partnerships. We also developed a Green Infrastructure Suitability Rating Tool that assesses how various green infrastructure methods can be expected to perform in a given situation.
Furthering the City’s mission to achieve 100 percent compliance with both federal and state clean water laws, the master plan we developed complements the use of gray infrastructure with green infrastructure alternatives.