Ditchmen • NUCA of Florida Ditchmen • April 2017 - Page 27

LOW IMPACT STORM WATER SYSTEM MAXIMIZES RESULTS Using Low Impact Development (LID) in its plan to control storm water runoff in Sarasota, design engineering firm DMK Associates, Inc. (Venice, Fla.) was able to create a system that would protect a local aquatic preserve and reduce construction costs for local businesses. This concept reduces storm water runoff volumes, treats storm water pollution and beautifies the neighborhood. The LID project for the Englewood area of Sarasota incorporates environmentally- sound components such as bioswales, multiple layers of soil, separators and inlet filters to capture pollutants and treat a wide range of flow rates. Because these LID techniques maximize the effectiveness of reducing and treating storm water runoff in a small area, this project has become another standard of the industry. For several years, the Sarasota Board of County Commissioners had been planning storm water improvements for the Dearborn Street neighborhood of Englewood. The West Dearborn neighborhood has struggled economically, which some attribute to the lack of centralized storm water infrastructure serving the area. Sarasota County’s storm water management regulations would require any newly developed or redeveloped lots on Dearborn Street to include expensive storm water management systems on the site, designed and installed at the developer’s cost. The first goal of the storm water infrastructure upgrade was to improve and protect the water quality of the nearby Lemon Bay Aquatic Preserve by eliminating the discharge of untreated storm water from the entire Dearborn Street district. The second was to build a sustainable storm water management infrastructure that would eliminate the need for local businesses and commercial developers to bear the expense of implementing their own storm water treatment systems. This would have a favorable impact on the local economy, lowering the cost of new commercial construction and spurring the redevelopment of the downtown and its surroundings. The original design proposal relied on a large underground vault system to capture and detain storm water runoff. The concept of LID was recommended to the Board of County Commissioners as an alternative that would meet the storm water management requirements plus provide the additional benefits of neighborhood beautification, parking and traffic flow improvements and increased pedestrian safety. The West Dearborn Street LID Project of Sarasota had an original cost estimate of $7.2 million but by using the LID approach the cost was some $3 million less than the underground vault APRIL 2017 • DITCHMEN 27