BY JOHN A. NAGY
SLI Reporter
‘Great Condition’
Born and built under less than auspicious circumstances, the Lake Auman dam has undergone a series of repairs, reconditioning and upgrades that could eventually make the earthen structure one of the stronger dams in the region.
In a presentation before the Seven Lakes West board of directors during its Nov. 16 meeting, Dam Committee Chairman Dan Lambert outlined the dam’s history and a detailed list of projects that have strengthened the structure.
The work ranges from surface work — adding tons of the large rip-rap rock facing — to intricate underwater engineering to upgrade emergency drain valves and associated piping.
“This dam is in great condition,” Lambert told the board and about a dozen residents attending the meeting.
Lambert, a mechanical engineer by training, described in understandable terms the significant technical challenges committee members have encountered along the way to improving the dam.
Work to build the dam began in 1983. Standing more than 90 feet tall and spanning about a half mile, the dam at the time it was built was one of the largest east of the Mississippi River. The 1,000-acre Lake Auman was to be the centerpiece of the Seven Lakes West development, begun in 1979 by a series of partners that included Seven Lakes “founder” Fred Lawrence.
But a series of financial troubles soon followed Lawrence and plagued development of the community and the dam. Lawrence ultimately was convicted of federal securities violations, and the development suffered through bankruptcy.
The dam itself was finished in 1986 — the lake took another eight years to fill — but its construction and engineering were not designed to stand the test of time or the pressure created by holding back 8.6 billion gallons of water.
The biggest upgrade to the dam came in 2009 when the structure was shored up with a slurry wall injection of nearly impermeable bentonite, mixed with concrete.
“We were leaking very badly,” Lambert said.
That project, which the state approved in 2010, went a long way toward improving the dam’s strength. Lambert said out of a 90-foot-tall dam, the injection of the slurry in some places had to go as deep as 40 feet before finding hard-packed clay.
The dam committee’s focus of late has been replacing and upgrading the emergency drain system. Parts of this project involved removing and replacing aged valves and using divers to pour concrete and install replacement systems. The first phase, done 90-feet below the surface, involved replacing the dam drain valve.
One of the biggest challenges for the workers was removing the 3,200-pound drain valve through 385 feet of concrete pipe. Workers devised a sled system to essentially scoot the massive metal valve out.
Other work recently completed included placing more than 430 tons of rip rap and dredging the dam’s discharge channel to ensure a clear path. The committee is also working to improve security around the dam, including posting signs and motion-activated cameras.
“Rest assured, Lake Auman Dam is in great condition,” Lambert’s presentation concluded. “It does require attention and action, and it’s getting both.”
Contact John Nagy at (910) 693-2507 or John@thepilot.com.
