To drain the lake into the Little Conococheague Creek, the dam control tower's lower gate was opened until water remained only in a 10-foot-wide channel running through the center of the lake, Smith said.
Water in that channel ranges from about five feet to at least 15 feet deep, and should be sufficient to preserve the lake's fish until water levels return to normal, he said.
C.A. Kibler Co. of Funkstown, Md., will patch holes and repair cracks in the dam's concrete control tower and will service the upper and lower gates controlling the lake's water level, said state Department of Natural Resources project engineer Andy Hanas, who drafted the renovation plans.
The contract calls for work to take 60 days, but Hanas said it there is a chance it could be completed in 30 days. Afterward, rain water, the creek and nearby mountain springs will refill the lake.
Although the process overlaps with this year's fishing season, some local fishermen regard dam repairs as a high priority.
A retired engineer and regular fisherman at the lake, Paul Horst of Hagerstown said he appreciates the importance of having maintenance work done.
"What's important is to get this thing repaired so we can come back," he said. "There are a lot of other places around to fish."
"It's a necessary evil - you just have to grin and bear it," said fly fisherman Rob Gilford, owner of the Rod Rack in Frederick, Md.
Once anglers and visitors overlook the "cosmetics" of the drained lake surrounded by mud and understand its purpose, "99 percent of them love it," Smith said.
Any danger to the lake's 14 species of fish or surrounding wildlife are based on misconceptions, Smith said.
"We haven't seen a dead fish yet," he said.
In fact, the health conditions and growth rates of some fish might improve, in part because biologists will establish shelters on the lake's bed, said John Mullican, a fisheries biologist for the Maryland Fisheries Service's western region.
The low water levels have attracted several species of water fowl, shore birds and other wildlife seeking food and safety from predators, resulting in a "balanced habitat," Smith said. He said he might begin drawing down water each fall to repeat that effect.
Mullican said he expects the fish population and water level to rebound fairly quickly following construction work, unless low oxygen levels or high temperatures kill large numbers of fish.
Hanas said the month-long deadline is a "hope" and time required to complete the work will depend on the weather and any difficulties contractors might face.
"If it takes two weeks, then we'd all be doing cartwheels," Hanas said. "If it takes 58 days, well, it's still got to be done."
The state Department of Natural Resources authorized the draining of the lake and paid $24,998.10 to the contractor, who submitted the lowest of five bids ranging up to $100,000.
The dam was in line for a routine assessment and maintenance that statewide dams 25 to 30 years old must undergo, Hanas said.