Silt washing into Lake Knickerbocker over the last 20 years has clogged an inlet so heavily homeowner David Gleason removed his dock some time ago.
It would not float anymore because of the buildup.
But silt isn’t the only threat to the lake, which backs up to the Chattahoochee Golf Course north of downtown Gainesville.
“We’ve got some issues with the dam,” Mayor Danny Dunagan told The Times on Tuesday.
Gainesville is responsible for maintenance of the dam, which separates Knickerbocker from Lake Lanier and spans East Lake Drive.
While concerns have been raised about the integrity of the earthen dam, Dunagan cautioned that maintenance work, which includes removing trees, stumps and other vegetation, should solve the issue and ensure stability.
“It’s not about to give way or anything,” he added.
But remedying the problem needs to begin now, Dunagan said, and he expects the city to bid out a contract for the work once officials have determined the scope of the project.
“We’re not equipped to do that,” he added.
Hall County Commissioner Billy Powell, whose district includes the lake, said he thinks maintenance needed on the dam could cost $1.2 million or more.
The focus on dam maintenance comes as city and county officials search for funding to stop the flow of silt into Knickerbocker and dredge the estimated four- to five-foot layer spread across the bottom of the 45-acre lake.
Officials said there is no sense in tackling the issues separately, and that they are looking at all possible funding sources, particularly grants from federal and state environmental agencies.
Residents have complained for years about silt pouring into the lake as a result of inadequate drainage infrastructure and the emergence of new development in the area.
“Nobody but nobody has taken responsibility,” said Gleason, president of the Lake Lanier-Knickerbocker Protective Association.
Until now, it seems.
“Everybody recognizes that there is a problem,” Powell said. “The dam needs to be addressed as a first step.”
According to a survey completed about seven or eight years ago, an estimated 32,000 cubic yards of silt had been deposited in Knickerbocker at that time, and residents tried in vain to raise the money needed to dredge it, Gleason said.
Gleason said he thinks the amount of silt in the lake is upward of 45,000 cubic yards today. It is unclear what it would cost to dredge this amount.
Residents would also like to see new infrastructure built to stop the flow of silt into Knickerbocker from Ada Creek, for example, and prevent a repeat experience once dredging is complete.
But this is an obvious additional cost.
Similar siltation problems have surfaced in Lake Lanier coves over the years, and dredging has proved expensive.
For example, runoff from developments channeling down Slaughterhouse Creek, a narrow stream flowing through the Hollywood Hills subdivision off Thompson Bridge Road, undercut banks, exposed roots and downed trees, driving silt and sedimentation into the cove where it empties.
The cove was dredged a few years ago at an expense of nearly $200,000 to local property owners, according to residents in the area.
And in 2008, the U.S. Army Corps of Engineers dredged 125,000 cubic yards of silt from Longwood Cove, a $2.3 million project that also involved building a retaining wall and extending the greenway that runs into the adjacent park from downtown Gainesville.
Gleason said he hopes the cooperation between residents and local government continues, and believes providing greater public access to the lake will generate more interest in removing the silt and, potentially, more financing to do so.
Either way, the “drawn-out process” is “not an easy fix,” Dunagan said.