Officials push to fix Conestee Dam to avoid ‘catastrophic’ break

GREENWOOD, S.C. (FOX Carolina) - Tucked away in a cove off Lake Greenwood, Ralph and Lisa Cushing found their dream spot to retire.

“We, you know, had big plans of being here the rest of our lives,” said Ralph.

But that sunny plan became murky months after they moved in.

“I don’t think I want to live on a toxic lake for the rest of my life,” he added.

Fifty miles north of the Cushing home sits the Conestee Dam.

The stonemasonry dam was completed in 1892 and is standing the test of time.

“Somebody who knew something built a dam that could last that long, but it won’t last forever because nothing does,” said Conestee Nature Preserve Operations Director Erin Knight.

“It is 70 years past its engineered life. It could fail at any time. It could last another ten years; we have no idea. We don’t know if it’s solid, if it has voids in it, and the investigation of that is impossible because as soon as you drill into it, you run into the risk of a cascade failure that could lead to a dam breach,” added Kelly Lowry.

Lowry is the Trustee for the Conestee Dam Restoration Project.

“The immediate aftermath of a dam break would be really catastrophic,” he says. “It’s a South Carolina concern for sure.”

Lake Conestee is full of contaminants from the textile mills that boomed in the Upstate from the 1890s to the mid-20th century.

“There was really little regulation about what could be dumped into rivers, so a lot of that came down the Reedy, and until it came to the lake, which was 130 acres originally, that stuff did not settle out, but it came and slowed right behind the Conestee Dam, and it remains there today,” explained Knight.

The Conestee Nature Preserve inherited the contamination and has managed the area around the lake for the last two decades.

Sediment in Lake Conestee collected by DHEC in 2021 shows concentrations of Arsenic, Cadmium, Lead, and Mercury all above EPA-acceptable standards. There are also higher than acceptable levels of pesticides and PCBs.

“As you get long-term exposure, health concerns could become a problem,” said Furman University Assistant Professor of Water Resources Dr. Gustavo Coelho.

Officials estimated there are between 2 million and 3.25 million cubic yards of sediment in the lake impacted by hazardous materials, enough to fill a football stadium 1.5 to 2 times.

“Most contaminants are contained in the Dam, and in case we have a spill or a break of the Dam those contaminants would go and spread downstream,” said Coelho.

That spread could go down to Lake Greenwood, Lake Murray near Columbia, and Lake Marion towards Charleston.

“It’s pretty much always on our mind. It isn’t just something that occasionally we’ll think about because I see how beautiful the lake is. It’s a big problem that has to get fixed,” said Cushing.

Officials have a solution in mind, creating a new dam a few feet downstream from the current one.

“The two would function really as a whole, they would work together to hold back the river and to hold back the sediments that are behind the existing dam,” said Lowry.

The price tag for that is $47.5 million.

“This is the year to do it, we have everything in place, and there’s no reason why we shouldn’t be moving forward,” said Knight.

The South Carolina legislature is debating whether to fund the solution. Lowry says the money could also come from private businesses, cities and counties in the area. He also didn’t rule out the possibility of federal funding.

After the new dam is funded, it will take three years to complete.

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