The Savannah River’s oldest dam is showing its age more than ever — and might need a facelift sooner, rather than later.
“The structure itself is sound, but it needs to be stabilized,” said Andy Cheek, a former Augusta Commissioner who has lobbied for repairs to the city’s Diversion Dam near the Augusta Canal headgates.
“There are more and more places that are weak and need to be rebuilt, repaired and strengthened,” he said. “In some places, we’re seeing erosion with up to 25 percent penetration of the 18-foot width of that dam.”
Built in 1875, the simple structure slices across the river near the headgates, backing up enough water to provide a consistent flow into the canal, from which the city’s drinking water is extracted a few miles downstream.
Cheek, who has approached city officials in past years about addressing the dam’s needs, said it is difficult to document the dam’s deteriorating condition because the worst areas are obscured by the river’s flow.
“I’d like to try to get the commission to coordinate a low flow day with Stevens Creek Dam upstream in order to go out and do a full, new assessment,” he said.
Although the 137-year-old dam is a scenic component of the popular Augusta Canal National Heritage Area, it is also a functioning industrial dam that is essential to the city’s drinking water production.
Augusta Utilities Director Tom Wiedmeier said the most recent assessment of the dam occurred in 2011.
“After Andy Cheek had raised concerns about a year ago, we had our engineer, ZEL Engineers, take a look at it again,” he said. “They felt it had not significantly deteriorated since previous inspections, and it was not in danger of imminent failure, but it was in a condition where things would have to be done at some point.”
City officials had planned to address repairs to the diversion dam at the same time another project was undertaken to provide fish passage at the site.
The fish passage is a requirement likely to be included when the city completes a protracted re-licensing process with the Federal Energy Regulatory Commission for its canal and diversion dam.
“The trigger to build a fish passage is when we get the FERC license,” Weidmeier said. “But that process has taken a lot longer than we thought it would.”
Commissioners were told a year ago that the license was likely to be issued soon, at which time the repairs to the diversion dam could be planned concurrently with the design of a fish passage.
If the license negotiations continue to move slowly, he said, the repairs may have to be undertaken before then,
The most recent work on the dam occurred in 2005, when a $400,000 project replaceed some of the removable timbers built into five gaps in the dam. Prior to that work, it had not been repaired since 1927.