Hitchcock Woods, located in Aiken, South Carolina, is one of the largest urban forests in the country and is a South Carolina Department of Natural Resources Heritage Site, thus when stormwater runoff was damaging its health with erosion, sedimentation and pollution, a solution was needed to protect the area.
Because the watershed was developed prior to modern day stormwater management requirements, there are few stormwater best management practices in place. Jason Hetrick, assistant director of Water Resource at McCormick Taylor said storm drains within the City of Aiken have been collecting and discharging stormwater runoff from 1,109 acres of urban watershed into the Sand River via a 120-inch storm drain pipe for decades.
In 2018, the city adopted the Sand River Stormwater Implementation Plan to address the runoff from the downtown area into Hitchcock Woods. In 2020, McCormick Taylor began working on one of the recommended projects, which was to create approximately 25-acre-feet of stormwater storage within the Sand River watershed. During the design phase, the project team had to find a solution to maximise the amount of stormwater stored within the limited area site, thus, two interconnected 15-foot vaults were chosen to store and control the runoff.
In the future, a passive park will be built atop these BMPs as part of site restoration efforts. The park will consist of pervious rubber sidewalks, demonstration pollinator gardens, a rain garden and educational signage.
“The project is important as it takes a huge step forward in addressing the watershed’s stormwater problems and the erosion within the Sand River,” Hetrick said. “Through the use of new technology, CMAC, paired with traditional grey infrastructure, stormwater vaults, the enhanced efficiency of this system will allow the City to implement almost complete management of the 10-year storm event within the 1,109-acre watershed, all within one location, saving millions of dollars from having to install multiple detention ponds throughout the watershed.”
Location: Aiken, South Carolina
Cost: $15 million
Size: 25 acre-feet
Owner: City of Aiken
Designer: McCormick Taylor
Contractors: Thalle Construction Company
Manufacturers: StormTrap and OptiRTC
