Rain, high tide aren’t the only reasons Bluffton Parkway flyover flooded Sunday evening
Access ramps to the Bluffton Parkway flyover were closed in both directions for about an hour and a half during a thunderstorm Sunday night, but it wasn’t just heavy rain that caused the roads to become temporarily impassible.
It also wasn’t a flaw in the design, according to Eric Larson, Beaufort County’s stormwater utility manager.
Lawson said Monday that the flooding happened when a filter at the base of the westbound section of the flyover became clogged.
“It wasn’t engineered to flood,” he said in a phone call. “We got an inch and a half of rain in a very short amount of time. That’s a high quantity of water that can’t get through the filter fast enough.”
The National Weather Service reported 1.16 inches of rain yesterday in Savannah, which is the closest rain measuring site to Bluffton. That amount is about 40 percent of all rain the area has received so far in August.
However, this was the first time that rain — unrelated to the a hurricane — closed the flyover, which opened in July 2016.
Larson attributed the flooding to two factors: first, the clogged filter at the base of the flyover ramp overfilled with road debris, which includes anything from litter and tire scraps to clusters of leaves and branches; second, the rain fell fast, exacerbating the problem.
“It had been about a week since it’s rained and a lot of debris collects on the roadway in a week,” he said. “We clean the filters monthly, but after last night, we cleaned the filter, replaced it and put the filter back in.”
The flyover closed at roughly 7:30 p.m. Sunday, and according to Beaufort County Sheriff’s Office Capt. Bob Bromage, it reopened at around 9 that night
Although the flyover reopened quickly, Larson said his department wasn’t aware of the flooding problem until this morning.
“We were never contacted to respond,” he said. “We found out on social media this morning.”
Larson added that Beaufort County will implement its own street sweeper this fall. The county’s currently contracted street sweeper operates quarterly, though that contract will not be renewed, Larson said. He does not yet know whether the county-owned sweeper will clean the roads more often than it has been
Even with its own street sweeper coming, Larson said road debris will always be an issue.
“You still get debris on the road, no matter what you do,” he said. “Aside from educating residents not to litter, there isn’t much we can do about it.
The filters, too, are not the problem, he said. Larson expressed his confidence in their continued ability to mitigate road debris.
“These filters are designed for a 25-year storm event and last night did not exceed that,” he said. “So we’re not going to change what we do. We have a procedure in place.”