Hall County officials are hoping a new set of construction codes will guard against widespread culvert failures in case of a repeat of what occurred May 19.
A resolution approved last month by the Board of Commissioners set new standards for culverts and stormwater pipes, requiring new underground structures to be made of “more durable materials with higher life expectancy, so as to protect the financial resources and other interests of Hall County.”
Basically, rust-prone, corrugated metal pipe is prohibited under driveways crossing live streams. And subdivision builders can only use concrete or high density polyethylene (HDPE) pipe in places where there’s a live stream or under county roads.
“From catch basin to catch basin, the culverts that run parallel to the road, they can still be metal,” County Engineer Kevin McInturff said. “The ones leaving catch basins going down to the backs of people’s houses can still be metal, as long as they’re not in a live stream.”
The county changed standards a couple of years ago, allowing metal culverts in streams but requiring a concrete bottom.
“But because of all of our issues we had this spring and summer, we thought — and the commission agreed with us — maybe we should look at eliminating it totally,” said Ken Rearden, Hall’s public works and utilities director.
“We think, that with these changes, the safety of our streets going forward will be a lot better.”
Commissioner Scott Gibbs said at a meeting where the resolution was presented that he was all in favor of the changes, “just to cut down on the losses.”
“After the million-dollar experience this year, I’d like to curtail that down the road,” he said. “The more population we have, the more roads we have. We need this to cut down on liability. There’s no perfect material, but (concrete or HDPE) help extend the life of some of this stuff.”
Governments are required to keep track of, inspect and maintain culverts, or structures that are supposed to keep stormwater flowing unimpeded to major river basins — Chattahoochee or Oconee, in Hall County’s case.
Hall, Flowery Branch and Oakwood hold stormwater discharge permits under the Georgia Water Quality Control Act and the Federal Clean Water Act.
Culverts are structures serving as small bridges under roadways, but they can be any tunnel or a drain that carries a stream or drainage from one side to the other.
“There’s thousands and thousands of them” in Hall County alone, McInturff has said.
Drenching rainfalls earlier this year caused problems for public works crews in city and county governments throughout Hall, including flooding, fallen trees and damaged roads.
But one of the worst — and costliest — impacts was culvert failure.
During the May 19 floods, several roads crumbled because of underground pipes giving way, including on Stephens Road in West Hall and McEver Road at the Oakwood-Flowery Branch line. An overflowing Mud Creek was the culprit in both cases.
Hall County, Flowery Branch and Oakwood all declared a local emergency after the flooding, with Hall requesting $814,000 in assistance from the Georgia Department of Transportation for repairs to Trudy Road, Cove Creek Trail, Stephens Road and Malibu Ridge.
The county is still doing culvert repairs, including on Bolding Road at Ga. 53/Winder Highway in South Hall and Talmo Road at Ed Cobb Road in East Hall.
The Bolding culvert was an old concrete pipe and the Talmo one was “a large metal pipe eaten out at the bottom,” McInturff said.
By the end of the month, both projects are expected to be completed, allowing affected stretches of road to reopen, officials said.