Providing Regional Detention and Passive Park Space: Win-Win for Sandy Springs City Center

David Braswell, PE

The City of Sandy Springs new city center was to be developed in an existing older commercial district within the municipality. The site was located within a basin that was over 64 percent impervious and drained to a tributary to Marsh Creek that was listed as an impaired stream for fecal coliform. Marsh Creek was also heavily eroded, with steep banks and undercutting channel, resulting from the frequent flash floods from the heavily impervious basin. With the new City Center being a focal point for redevelopment of the area, the City identified the Marsh Creek Stormwater Improvement Project from their watershed improvement plan as a first step in improving water quality and downstream erosion issues within Marsh Creek and meeting their stormwater control requirements for redevelopment of the 32-acre basin.

The project included land acquisition issues, coordination with multiple stakeholders, improvements to existing infrastructure, policy development for redevelopment of the basin, and the design and installation of the proposed stormwater treatment facility. The best management practices for the site included a trash removal system, permeable pavers, bioretention basin, permanent pond and flood storage for attenuating storm runoff to natural peak flow conditions. The project was designed within a passive park setting with walking paths, park benches, and educational signage around the facility.

A monitoring plan will study the efficiency of the BMP’s on improving water quality, including TSS and Fc. This information will provide the City with a demonstration project for possible duplication in other parts of the community.

Presented by David Braswell, PE

WK Dickson & Co, Inc.

David has over 38 years of experience in water resources and stormwater management projects. He currently serves on the Etowah/Coosa Basin Advisory Committee for the MNGWPD, where he stays informed of current and proposed District policies, EPD/EPA rule changes and BMP and TMDL implementations. During his career, he has served as project manager or project engineer on over 30 Flood Insurance Studies for FEMA throughout the Southeast and has been a project manager on stormwater projects in Metro Atlanta for over 30 years. Typical projects have included pipe and culvert replacements, detention pond assessments and retrofits, dam-break studies, water supply studies, spillway designs, and the design of stormwater detention facilities and BMPs. Where feasible, many of David’s projects have included Green Infrastructure measures that improve water quality and provide community amenities.