July 04–Five alternatives for creating fish passage past the aging New Savannah Bluff Lock and Dam at Augusta were unveiled to the public June 26, some to mixed reviews and a lot of ongoing concerns about flood control and the impact they might have on riverfront homes.
The U.S. Army Corps of Engineers Savannah District unveiled the alternatives it will be studying as a solution allowing endangered shortnose sturgeon and other fish to migrate past the Lock and Dam to historic spawning grounds “being blocked currently by the Lock and Dam structure,” said Laurie Sattler, the senior projects manager for the district. The fish passage is necessary to mitigate damage that the Savannah Harbor expansion will cause to spawning grounds on that end of the river from the infiltration of saltwater from the harbor’s deepening, she said.
The Corps had studied repairing the Lock and Dam and then creating a fish passage that would essentially be a new channel for the river around the structure prior to the passage of the Water Infrastructure Improvements for the Nation Act in December 2016. That law decommissioned the Lock and Dam; required the Corps to maintain the pool of water that Augusta, North Augusta and many industries rely on; authorized the Corps to build a rock weir or similar structure for fish passage; and once built allowed the Corps to remove the Lock and Dam.
Prior to that, the repairs and the fish passage the Corps was studying would have come in around roughly $64 million, Sattler said, although the Corps had not done a survey underwater to see what repairs might be needed under the surface. While they have not yet done detailed cost analyses, all of the alternatives except one come in around that same price, she said. One that would have a rock weir for fish passage and two 50-foot gates would probably come in at 2.5 times that amount, Sattler said.
“It’s pretty expensive,” she said.
One alternative would allow some repair of the Lock and Dam and then a 200-foot-wide fish ramp through what is currently Lock and Dam Park. The other three are essentially variations on the same theme, with rock weirs of different heights and then a designated flood plain area through part of the park to allow higher water flows to go around the weir, said Beth Williams, the chief of the hydrology and hydraulics branch for the district.
The weirs would allow water to flow over the top and would be gently sloping connections of pools allowing fish to swim their way through the structure, she said. While some in the audience questioned whether the fish would really do that, the concept has worked with a similar structure on the Cape Fear River in North Carolina, said Fritz Rohde, a fishery biologist with the Beaufort, N.C., office of the National Oceanic and Atmospheric Administration.
Vaughn Maxwell of North Augusta was concerned about flood control and the possibility of silt building up behind a rock weir in the river. But Williams said silt tends to drop out in several areas before it reaches that spot, most notably where the flow of the river enters the pool upstream, so “we don’t expect that to be an issue.” Currently the Lock and Dam isn’t really used for flood control, so a rock weir also wouldn’t have much impact during high-water events because it is on the river channel, and that water tends to spill over the channel banks, Williams said.
While they would maintain the pool, all of the alternatives would tend to hold it lower than its current fluctuation of 10 to 13 feet deep at the Fifth Street Bridge during normal flows, with some at 10 feet and others somewhat lower. That concerned Scott Lewis because he can already put on waders and walk out from his property on the riverbank about 40 yards into the river.
“If you drop it three feet, that’s all going to be land,” he said.
Chip Lasher, a member of the Augusta Rowing Club, said the river needs to be at a certain height to allow big events such as the Head of the South regatta.
“If it goes too low, we’re going to have to find somewhere else to have that regatta,” he said, which generates a lot of money for Augusta.
Leroy Simkins Jr., a longtime advocate for repairing and restoring the Lock and Dam, said it was good to finally see what the Corps was thinking.
“Now we have a little bit better idea of what we are fighting,” he said. None of the alternatives would keep the lock, and Simkins said that is wrong.
But the rock weir plans, particularly one that would include the highest weir height plan to keep the most water in the pool, were a welcome sight to Savannah Riverkeeper Tonya Bonitatibus.
The Corps will return with a draft recommendation plan probably in February, Sattler said. Construction on an alternative must begin no later than January 2021, she said.