Riverkeeper: Be ready to handle sediment ahead of Hurricane Florence
For Catawba Riverkeeper Sam Perkins, weather is no excuse.
“No one can really be caught with their pants down,” he said, “because we know that this is coming.”
Rain and construction are a recipe for runoff. When Hurricane Florence hits, there’s likely to be plenty of both. Sediment pouring into area streams, rivers, lakes and storm drains has been an issue in and around York County for several months. Residents reported it. County leaders called for change.
With Hurricane Florence blowing in on the Carolina coast, Perkins knows it’s about to get wet. When heavy rains hit dirt turned up by construction, that dirt can flow past silt fences and other stormwater structures into local waters. Runoff build up can shallow coves. It degrades water quality. It can harm aquatic life.
“We’ve had a couple really wet spans already this year, and we’ve seen a lot of problems from that,” Perkins said. “This could not be a situation, with this hurricane, with more forecasting.”
High-growth areas such as Fort Mill, Tega Cay, Indian Land and Lake Wylie are susceptible with large residential or commercial construction.
Trish Startup, spokesperson for York County, said Tuesday afternoon the county environmental compliance department is drafting a public service announcement “that will address some actions to help reduce the potential impacts from forecast heavy rains.”
“It is also understood that rain events which may be forecast above the 100-year storm event exceed current state of South Carolina design standards and have the potential to effect or overwhelm not only new construction sites, but also existing infrastructure across the county,” Startup said.
Scott Edgar, an engineer for Lancaster County in stormwater management, said his county has been in contact with builders.
“We are trying to get our large construction sites to button everything up,” he said. “The (stormwater) measures that are required are designed for a certain storm. They’re designed to withstand a 100-year flood.”
Stormwater devices should be able to handle 5 inches of rain in 24 hours. Edgar said Tuesday morning he saw projections of 2 or 3 inches with Florence.
“If that’s the case, it shouldn’t be that much worse than any other storm,” he said.
If the system stalls in this area or rainfall is significantly more than expected, flooding could occur.
“We will do some preemptive looking at the backs of dams and seeing where those are,” he said. “We’re gearing up. We’re planning for the worst and hoping for the best.”
Perkins went Monday afternoon to check out and shore up the Catawba Riverkeeper Foundation boat on Lake Wylie.
“It should be manageable,” he said. “It’s something that everyone really should be prepared for. There is no excuse.”
Much of the work falls on builders, he said.
“The sediment basins should be cleared out, all the fences should be up,” Perkins said. “Hopefully, the land will be stabilized. If they need to move to something engineered, that’s what they should do.”
Sites like Bonum Road in Lake Wylie, where significant spills have occurred, are of particular concern.
“These sites around here that have been big problems for sediment getting off and filling in the backs of coves, should be absolutely pristine and ready to handle this rain,” Perkins said.
High winds could cause more than sediment problems on the lake. Anything from small limbs to power pole sized wood, chunks of dock and even whole boats could float loose from a major storm.
“Any time there’s a big storm, the debris kicks up and it’s so prevalent,” said Capt. Adam Huth with TowBoat U.S.-Lake Wylie, which helps stranded boaters. “There’s tree trunks and floating debris in the water. You have to go slow and watch out.”
Huth, who has more than 20 years experience responding to water emergencies, says prepare in advance and stay off the water.
“Lake Wylie has a lot of open boats. With a torrential storm, a lot of those open boats can get overcome with water pretty quick,” he said Monday. “You really want to still take extra action to secure that boat.”
Boaters and waterfront homeowners are asked to secure items. Each fall the Riverkeeper Foundation holds Riversweep, where volunteers collect tons of trash and debris from Lake Wylie.
“Just be aware,” Perkins said. “We could see some heavy winds, so please make sure you don’t have anything loose that could blow into the lake that we’re going to have to get at the next Riversweep.”
Report a problem
If stormwater structures fail, it’s important to photo or video the source of the muddy water at the time, Perkins said.
Include information, including site location, which stormwater feature is failing, and if water is running into drains, streams or the lake.
Unless the weather makes it unsafe to be outside, it’s best to get as much real time information as possible, he said.
“I know sometimes it can be uncomfortable getting out in the rain, but you really need to get out while you see the problem actively happening and document it,” Perkins said. “Do pictures, do video, zoom in, zoom out. Get yourself as much context as possible.”
Contact the county environmental compliance staff as quickly as possible at 803-909-7157 or https://maps.yorkcountygov.com/gvh5/index.html?viewer=tide.