Roswell Area Park Culvert Replacement
Campbell Civil Consulting worked with DMD Engineering Testing, Carmichael Development LLC, and the City of Roswell Department of Parks and Recreation to replace a set of failing corrugated metal pipe culverts at Roswell Area Park. The project necessitated coordination with the Army Corps of Engineers, as well as the Georgia Department of Natural Resources Environmental Protection Division, for the potential of impacts to Waters of the United States and state stream buffers. Campbell Civil Consulting coordinated closely with the City of Roswell Public Works / Environmental department on these issues, as well as their ongoing flood plain remapping efforts.
The project was typical of many modern elements of failing infrastructure in the Greater Metro Atlanta area, which experienced its first major development boom in the early 1980s. Most storm drain culverts of the time were constructed of corrugated metal pipe, which has an approximate 30 year service life. As a result, certain elements of the stormwater infrastructure are beginning to crumble all across Metro Atlanta, and must be replaced at great cost. The modern environmental regulatory environment complicates these issues, as any work within a stream is subject to a layer cake of federal, state, and local guidelines, each of which must be followed and adequately addressed.
For this project, Campbell Civil Consulting stepped in to the process as the engineer of record, designing the culvert replacement within regulatory parameters laid out by Roswell Public Works, working with their staff to match their regulatory efforts for state buffers and flood plain mapping. CCC acted as a sub consultant for the program manager DMD Engineering and Testing, so they could offer a turnkey solution to Roswell Parks and Recreation. CCC's efforts included working closely with Public Works to develop a unique diversion strategy to eliminate erosion during construction, by pumping the base flow of the stream around the project site and discharging it into the wide and heavily vegetated flood plain, allowing the riparian vegetation itself to act as a filter for diverted water to remove silt and other pollutants before the diverted water reentered the stream. At Roswell's request, CCC also developed a downstream energy dissipation solution in keeping with FHWA HEC-14 methodology, which prevents scour in the receiving channel due to the crossing.
In order to reduce the necessary diversion time, custom precast headwalls were provided by Oldcastle Precast that narrowed the width of the creek crossing within limits set by state stream buffer variance guidelines. Construction was provided by Carmichael Development LLC.
Some photos of the project are included below.
Previous Corrugated Metal Pipe Culverts:
Diversion discharge into flood plain, primary treatment via infiltration and filtration through a rock filter dam and through existing vegetated media:
Diversion discharge to creek - less point discharge due to infiltration, remaining surface discharge is clean: