Lake Forrest Drive isn’t the only road in Sandy Springs that’s created by cutting a vertical slope, but it’s the most notorious one.
It might also be a learning opportunity, according to Sandy Springs City Councilman John Paulson.
“This isn’t the only vertical/near-vertical rock face in the city,” Paulson said during the Aug. 6 City Council meeting. “We’ve now got a process in place to start looking at the rest of these.”
City Council on Aug. 6 gave the OK to awarding an emergency contract in order to speed up repairs on a closed portion of Lake Forrest, between Lake Summit and Chevaux Court. Repairs won’t begin until September, at the earliest, and will likely take several months.
Paulson said Lake Forrest repairs could be useful in helping the city tackle repairs on other vertical roads.
“The question of preventive maintenance we have not really talked about for other areas because of the emergency nature of this,” Paulson said. “There may be things we can do. The point is being aware of them. The staff is already aware of the other locations and we’ll just keep an eye on them.”
City Spokesman Dan Coffer said other roads with vertical slopes include Glenlake Parkway, Glenridge Drive, New Northside Drive and Powers Ferry Road. He said none of the city’s other vertical roads are in the same condition as Lake Forrest Drive.
Coffer said the bulk of the service calls, eight of 13 this year, were to clear up rock slides on Lake Forrest.
Lake Forrest is cut vertically into the rock face and the soil underneath it isn’t stable enough for a routine repair job. Engineers will have to explore ways to reinforce the vertical wall, like a soil-nail or gravity wall.
Paulson, who works as an engineer, said vertical cut slopes can weaken the quality of the soil.
“Over time, the rock that was cut into starts weathering and turning into soil, so it changes its composition and its strength,” Paulson said. “That’s what’s happening at Lake Forrest. That rock used to be very competent rock. It’s not as stable when it turns into soil.”
The road closure has created headaches for north bound-south bound drivers looking for an alternative to Roswell Road, and for students attending Heards Ferry Elementary. Fulton County School officials have moved a bus stop used by children whose families live around the closed section of Lake Forrest. The condition of the road could also pose a threat to nearby homes.
When consultants assessed the road’s condition this summer, they had to bore down as far as 40 feet to find stable rock.