Residents of both South Carolina and Georgia got a glimpse of five alternative plans the U.S. Army Corps of Engineers is considering for the New Savannah Bluff Lock and Dam.
At The Boathouse along the river in Augusta, the Corps of Engineers presented those five plans to the public. The alternative plans would allow the safe passage of sturgeon as well as maintain the current pool created by the lock and dam for recreational purposes.
The Savannah Harbor Expansion Project (SHEP) would have created a new river channel around the current lock and dam, but the Water Infrastructure Improvement for the Nation Act (WIIN) deauthorized that option.
Laurie Satter, senior project manager for the Corps of Engineers, said during the presentation the WIIN Act requires a solution that would allow in-channel fish passage, deauthorize the lock and dam, and preserve the upstream pool.
The Corps of Engineers is required to find a solution that would allow sturgeon to pass through via the Endangered Species Act, Satter said.
Beth Williams, chief of the hydrology and hydraulics branch of the Savannah District of the Corps of Engineers, presented five alternatives to the original SHEP project to the public and to civic leaders Tuesday.
Williams said there were originally 33 alternatives, which were then narrowed down to the five.
The Corps of Engineers must meet the criteria for five needs: ability to pass fish, cost, navigation, water supply and recreation.
The first alternative presented is a project that would retain the current dam and allow fish passage on the Georgia side.
Williams gave the estimated depths of each of the projects at the 5th Street Bridge cross-section of the pool. The current depth varies between 10-13 feet, Williams said.
The project retaining the dam would give the pool an 11-foot depth at that cross-section.
The other four alternatives would each include removing the existing lock and dam and include a rock weir – a portion of the structure that slows water flow and limits erosion.
One option would allow just a rock weir, while each of the other three options would include either a floodplain, dry floodplain or gated bypass channel.
The four projects that called for the removal the lock and dam would leave the upstream pool between 8.5 and 11 feet deep at the 5th Street Bridge cross-section.
Satter said the original SHEP plan was unofficially estimated at about $64 million. The alternatives she said, would be comparable except for the gated bypass channel, which would be around two times that cost.
Satter said in the fall of 2018, a recommended alternative would be chosen, and by February 2019, the commander of the Corps of Engineers South Atlantic Division would be the one to approve the report suggesting the chosen alternative.
During Tuesday’s meeting, the Corps of Engineers said there was not a current front-runner among the five plans.
The Savannah Riverkeeper has been advocating for an alternative that would include a rock weir, according to a press release on Tuesday.
“We are excited to see the majority of the options being proposed include a rock weir that is compatible with ongoing whitewater efforts, and will bring many benefits to the health of the river, fish populations, and the community,” Tonya Bonitatibus, Savannah Riverkeeper, said in the release.