Dam engineers hope to complete design by October
Dam engineers with Schnabel Engineering gave Grady County commissioners an update on the progress being made on the dam design for the 960-acre Tired Creek lake Tuesday night.
Joe Monroe, Chuck Wilson and Bradley Boyer, all of Schnabel, along with Laura Benz of Wm. Thomas Craig’s office, the Tired Creek consultant, appeared before the commission this week.
Commissioners were updated on the soil testing and lab work that is continuing as engineers design the earthen dam for the lake project. The engineers were also here this week to seek guidance from the commission on a variety of options.
The dam being designed by the engineering team will be approximately 40 feet high and will accommodate a storage volume of 24,000 acre-feet.
After discussing some options for the dam design based on some permeable soils found at the site for the dam, commissioners instructed the engineers to use the 4-1 sloop and to design the spill way to handle 43.2 inches of rain in a 24 hour period.
The state minimum is a design for 21.6 inches in 24 hours, but commissioners favor building the safest dam and spillway possible.
Commissioners accepted the recommendation of the engineers to go with a concrete labryrinth-crested weir spillway, which has an accordion like design that gives the 78 foot spillway the same capacity as a 300 foot spillway.
Engineers also sought commissioners’ opinion on the need for bridges over the spillway and one to the riser in the lake. Joe Monroe, of Schnabel, said that either bridge could be designed and bid as an elective alternate or could even be added later after the lake fills and the county determined a need for the bridges.
However, based on the projections so far, according to Monroe, the county could include the bridges in the project and still come in right at or below the original estimate of $10 million for construction of the dam.
“It is purely a preference. As far as safety or a maintenance point of view they are not necessary,” Monroe said.
Commissioner Elwyn Childs said he would prefer to obtain the opinion of County Administrator Rusty Moye, who was absent Tuesday night due to health.
County officials were also asked to decide what type of slope protection they preferred for the dam. Engineers recommended concrete blocks, which they say is the most economical and is favored by state safe dam personnel.
The estimated cost of the concrete blocks is $520,000. Engineers favored the concrete blocks to a re-enforced concrete block wall due to the eventual settling and cracking that would occur.
Monroe said the blocks would be three to four feet tall and big enough to stand up alone or could be tied in. He also said the block option would make it usable for handicapped fishermen.
“It’s tough to fish on a slopping surface,” Monroe said.
Commissioner Ball asked the engineers Tuesday night when they could complete the design phase of the dam. The Schnabel engineers said they had been delayed slightly by weather, but still anticipated wrapping up the design phase in mid October or by late September as originally planned.
“We are not substantially delayed. We are talking about days not months,” Monroe said.
Chairman Norton urged the engineers to do everything possible to keep the cost of the dam construction as manageable as possible. “This is not a turn key facility. We will need every penny we can to build the dam and to put in the docks,” he said.
Consultant Benz said that so far most of the numbers for the lake project are coming in lower than anticipated rather than higher.
“That’s real good. Let’s hope we can keep it that way,” Chairman Norton said.
In related news, Grady County officials traveled to Savannah Wednesday to meet with U.S. Army Corps of Engineers officials regarding the Tired Creek lake project.
County Commissioner Chairman Charles Norton and County Attorney Kevin S. Cauley took part in a meeting of consultants representing Grady County in a meeting with the Corps to present a comprehensive report that includes plans for maintaining water quality, fisheries management and master lake buffer among others.
Norton and Cauley updated members of the board of commissioners Monday morning on the recent trip.
The county attorney said the decision was made in consultation with Wm. Thomas Craig, the county’s Tired Creek consultant, to wait until all of the Corps requested plans are complete and then present them all at one time as a complete package.
“The meeting went well. There were no hiccups or issues and nothing new came out it,” Cauley said.
The county attorney said that each project the Corps “tackles is unique and ours is no different.”
“We’ve received a lot of scrutiny. We have in the past and we will continue to, and we welcome that as we work to make this lake project as an environmentally friendly and noninvasive project as possible,” Cauley commented.
According to Chairman Norton, one of the issues the Corps asked to be addressed is that roads leading to proposed boat ramps be added to the drawings that accompanied the master plan.
Land planners and landscape architects David Malcolm and Charlie Johnson of Wood & Partners, consultants to Grady County, also traveled with the county delegation and they say the request would not be a problem.
Commissioner Al Ball asked if the project is moving forward or will be stalled while the drawings are revised.
Norton and Cauley reported that the Corps indicated it would respond to the county’s plans in the next couple of weeks, at which time the county will be able to respond, if necessary. At that point, the plans will be put out to other agencies with jurisdiction for comment. That comment period will last 30 days, according to Cauley.
“Meanwhile, we continue working on dam design anyway, so this is not holding anything up,” Cauley said.