If the aging Lake Forrest Dam on the Atlanta-Sandy Springs border were to fail, the first place flooded would be Meadow Valley Drive, which sits along the wooded creek the dam uses as outflow. And as the two cities and upstream homeowners ponder possible dam reconstruction options, downstream residents have tree preservation on their mind.
Leslie Laird’s house would be the first to go in a disaster; according to a 2009 letter from the state Safe Dams Program, a worst-case-scenario failure would send a 12-foot wall of water into her home. She’d like a repair option that saves the mature trees dotting the dam’s eastern embankment.
“I don’t want them to even touch the east side,” she said. “Sandy Springs does not need to lose any more trees.”
Her neighbors in the Cherokee Park Civic Association took that position after meeting with city officials about the repair options last August. But there’s one problem, according to Sharon Kraun, a spokesperson for the city of Sandy Springs.
“The existing trees will be removed with both options currently under consideration,” Kraun said. “Final design will determine if any future plantings are possible, but [they] would be very limited at best. For maintenance, structural and safety reasons, trees are not permitted to grow along the slopes of a dam.”
That makes for yet another complication in repair design options that have dragged on since 2009. A big factor is the dam’s location directly under the 4600 block of Lake Forrest Drive, right on the Atlanta-Sandy Springs border, which makes for complicated ownership and liability issues. Both cities, several individual homeowners, and a larger lake-owning group of homeowners called the Three Lakes Corporation all have repair responsibilities, according to the state.
In recent years, Sandy Springs has taken the lead on studying repair options, splitting the cost with Atlanta. The work included removing the fish from the lake and lowering its level by 12 feet. City-hired engineers say the dam has several problems that could cause collapse: those trees growing on its slope, a corroding pipe inside it, and an inability to handle the flow of water from a major rainstorm.
Last fall, engineers presented the Sandy Springs City Council with two repair design options: an upgraded version of today’s dam, known as the “full pool” option for restoring the lake, or a new, smaller dam built farther upstream in a “reduced lake” option. Either option could cost roughly $7 million and take years to complete: nine to 12 months of design and permitting, and 15 to 18 months of construction, possibly including the closure of Lake Forrest Drive during work.
Cherokee Park residents have favored the “reduced lake” option under the idea that it could save more trees. Neal Sweeney, the current head of Three Lakes Corporation, said in recent weeks that his group of residents strongly prefers the “full pool” option and has “momentum” in reaching agreement to move forward.
Sandy Springs City Councilmember Andy Bauman, who represents his city’s side of the dam area, said there is another certainty in the process: safety comes first. Cost is the second consideration. For neighbors like those in Cherokee Park, he said, there are concerns about the many construction impacts, including “loss of trees, wildlife, aesthetic and visual considerations.”
If all conditions are equal, Bauman said, he would prefer the full pool option. But, he added, “What I don’t want to do is build the lake back at the expense of downstream people.”
He said he has asked city staff for an independent “peer review” of the dam repair options by outside engineers, and for the city to tell affected property owners what difference each option makes, if any, for those living downstream.