THIS WEEK'S TOP STORIES
Flooding persists after showcase drainage project
By Jackie R. Broach
Flooding at the intersection of Highway 17 and Waverly Road continues to plague drivers this summer, though it was supposed to have been solved by a stormwater project Georgetown County completed earlier this year.
The $618,394 project was the first funded with county stormwater fees. It replaced drainage pipes under the highway, put pipe in place of an open ditch along the North Causeway and installed filters called Smart Sponges to catch debris and kill bacteria in stormwater before it flows into Pawleys Creek.
The work fixed the flooding problem temporarily, but it started again as a result of an ensuing road project by the S.C. Department of Transportation that added a left turn lane on Waverly Road.
Sediment from the DOT project clogged the filters.
“They’re designed for some sediment, but not the volumes that were coming down our way,” said Ray Funnye, the county Public Services director.
Without the sponges, the sediment from road work would have ended up in the creek.
The flooding started again more than a month ago and occurs after every hard rain, but neither Funnye nor Richard Pope, DOT’s resident maintenance engineer, were aware of the problem until this week, when they were shown a photo of a car turning into hubcap-deep water at the intersection.
Workers were promptly sent out to investigate the cause of the flooding.
“We’re in the process of removing [the filters] and getting them cleaned out,” Funnye said.
The filters should be back in place and functioning properly sometime next week. The county also plans to raise the shoulder of the road near the area where the flooding occurs, Pope said. That work should take place in the next week or two.
In the mean time, “we’re talking to the vendor who provided the sponges to make sure we’re on the same page as far as performance expectations and what we should do to maintain them under adverse conditions,” Funnye said.
Under normal conditions, the sponges must be cleaned regularly to remain effective, much like the filters in home heating and cooling systems, but county workers weren’t certain how often cleaning would be required when they installed the last of the sponges in April.
They planned to create an inspection schedule.
Pawleys Island Mayor Bill Otis questioned why they weren’t checked and cleaned earlier. There was little point in installing them if they aren’t maintained properly, he said.
The county installed Smart Sponges in 16 stainless steel catch basins between the intersection and the creek.
Aside from the clogged filter at the intersection, Funnye said a catch basin near the creek is about 3 inches higher than it should be so the filter only functions in very heavy rains.
Underground utility lines prevented workers from putting the catch basin as far down as they should have, Funnye said. The difference wasn’t expected to affect is function, but county staff has found the catch basin isn’t filtering stormwater from light rains. Heavier flows are partially filtered.
Funnye learned about the problem about two months ago.
“There’s nothing we can do about it,” he said. “We looked at relocating the utilities, but it’s cost-prohibitive.” He doesn’t know exactly how much it would cost, but “it would be expensive.”
Installing the filters and catch basins cost the county about $60,000.
Otis said he went out to look at the raised catch basin this week with a county employee after smelling of diesel fuel in the area.
“It’s pretty clear to my unpracticed eye that one of the catch basins is in the wrong place,” Otis said. “There’s no way the water coming off that road is going into that catch basin. You can see it’s going in below the sponge.”
He doesn’t believe lowering the catch basin will help.
“I think it needs to be moved,” he said.
He isn’t sure if the diesel smell originated from the catch basin or nearer Highway 17, but he said the county needs to look at that, too. He also plans to mention it to the S.C. Department of Health and Environmental Control.