Flowery Branch and Hall County officials walked along Flowery Branch Creek in March, inspecting drainage structures as they went. All seemed OK at the time, except for the need for some relatively minor fixes.
But they couldn’t anticipate the historic amount of rain that fell May 19, causing some $1.4 million in storm damage in the South Hall city.
“I think it’s clear that by the fact that we had (a culvert) study done, that we had done a visual inspection and followed through with some prudent maintenance, what happened here that day was so beyond what you normally plan for,” City Manager Bill Andrew.
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, County Engineer Kevin McInturff said.
The county is required to inspect 20 percent of those each year.
“We do that by road. We’ll hit 20 percent of the roads and look at every single culvert and pipe on that road,” McInturff said.
“We have to do some monitoring, we have to do mapping of these stormwater systems ... and there’s an educational component to (the permit),” he said.
“Basically, you have the permit that tells you all you have to do, and then you have the stormwater management program, which (describes) how we intend to meet requirements of that permit,” McInturff said.
The county works with Flowery Branch and Oakwood on compliance and stormwater control.
“Stormwater doesn’t care whether it’s in Oakwood or Flowery Branch or Hall County,” Oakwood City Manager Stan Brown said. “It’s all just trying to get to (Lake Lanier), and we’re trying to get it there.
“Jurisdictional boundaries don’t fall in line with drainage basins, so there’s a lot of cooperation and working together. We all share some of the best management practices that are covered under our permit.”
The Georgia Department of Transportation inspects some over 15,000 bridge structures, including larger culverts, throughout the state every two years,
“Some are inspected every year, when it is deemed necessary,” DOT spokesman Mohamed M. Arafa said.
If a structure fails, flooding can occur, undermining roads to the point of collapse and creating a public safety issue.
During the May 19 floods, several roads crumbled, including Stephens Road in West Hall and McEver Road at the Oakwood-Flowery Branch line. An overflowing Mud Creek was the culprit in both cases.
Andrew was headed to Flowery Branch on McEver early that morning and recalled what “looked like Niagara Falls coming through there.”
“I was probably one of the last people to get across (the creek),” he said.
Oakwood was laying plans to eventually replace the culvert when the storm struck, dumping as much as 7 inches in six hours in downtown Flowery Branch.
Work has started on the Stephens Road culvert and is expected to start soon on the McEver culvert, with work wrapping up on both this summer.
Hall County, Flowery Branch and Oakwood all declared a local emergency after the flooding, with Hall requesting $814,000 in assistance from the DOT for repairs to Trudy Road, Cove Creek Trail, Stephens Road and Malibu Ridge.
Oakwood requested $427,000 for the McEver Road project and Flowery Branch requested $381,000 for a culvert replacement on Cantrell Road at Spring Street.
The state pulled from its Local Maintenance and Improvement Grant emergency fund to provide about $200,000 to each of the governments, Arafa said.
“The floodwaters did some significant damage to these culverts ... eroding several culvert entrances, outlets and road embankments,” he said.
Stormwater problems are no stranger to Flowery Branch, particularly the downtown area, where a big portion sits on the side of a hill.
A culvert on Spring Street at Flowery Branch Creek failed in December 2009, stranding residents of a 50-unit apartment complex. The city contracted last year with Norcross-based engineering firm Pond & Co. to conduct a culvert study.
That study recommended — and the storm bore out the need for — replacing culverts on Mulberry Street, Phil Niekro Boulevard, East Main Street, Cantrell Road and Spring Street
Doing all the work with one contract could save time and money, Andrew said.
“Every time you bring out a company to do this work, you have mobilization costs and (expenses) if you do bidding every time,” he said.
“And frankly, interest rates aren’t going to get any lower, so this is the time to borrow money. And the prices of construction are only going to go higher.”
McInturff said he believes that generally speaking, Hall’s culverts are in decent shape, although there are some older structures that need attention.
Ken Rearden, Hall’s public works and utilities director, said, “With the older pipes, the county wasn’t as developed, so you didn’t have the impervious surfaces that would cause more runoff to them.”