What happened to Lake Murray dam wall this summer? Details could help terrorists, feds say
A federal agency that investigated conditions at the Lake Murray dam has declined to release more details about what led to a pedestrian walkway being shut down this summer, citing concerns that it could benefit potential terrorists.
The Federal Energy Regulatory Commission last week declined The State’s request to release copies of the incident report that noted movement in the dam wall at Saluda Shoals Dam on Lake Murray, and the investigation summary composed by Dominion Energy, the dam’s owner.
In a response to a request filed under the federal Freedom of information Act, FERC labeled the two documents as “critical energy/electric infrastructure information,” which exempts them from release to the public under federal law. The agency said more detailed information on structural issues at the dam could be used to intentionally damage the structure if it were made public.
The dam holds back 650 billion gallons of water less than 15 miles west of Columbia. The nearly 8,000-foot-long main dam on the Saluda River provides hydroelectric power generated from Lake Murray’s 50,000 acres of water held in place behind it. A dam failure could lead to much of the capital city region being inundated with floodwaters, state emergency officials have said.
FERC’s response notes that Dominion also requested the documents be treated as sensitive information. “They state that the two reports contain detailed construction drawings of portions of the dam, which could be useful to a potential attacker,” the agency said in the response.
“Commission staff has reviewed the documents, which include detailed construction information, drawings, and photographs related to the sheet pile wall, which could be helpful to individuals interested in damaging the facility... Accordingly, these documents will not be released.”
In June, federal inspectors noted that a sheet pile wall had recently rotated towards the lake along the original embankment of the Dreher Shoals Dam, according to a letter FERC sent to Dominion. The letter also noted damage to a concrete gutter and the pedestrian walkway after an inspection on June 23, leading to the closure of the walkway.
The letter from FERC noted “no problems that would present an immediate concern for dam safety or continued operation” of the dam, even as it expressed concerns about the impact on the southbound lane of S.C. 6, which crosses over the dam between Ballentine and Lexington.
The concerns led the S.C. Department of Transportation to barricade the walkway over the bridge for several weeks while repair work was done.
At the time, Dominion told The State that heavy rains on June 21 and June 22 caused a drainage gutter and the wall along the dam walkway to “settle,” affecting the pavement. “After completion of an initial assessment, Dominion Energy and an independent consultant identified no issues affecting the structural integrity of the dam,” the company said in a statement.
The initial disturbance was noted in an email and a phone call from Dominion’s chief dam safety engineer to FERC’s Atlanta office, the agency said. Dominion was asked to submit its own dam safety incident report to investigate the cause of the wall movement, its impacts and plans to enhance monitoring of the wall and embankment.
The federal agency’s finding means the general public won’t be given specifics of the incident and whatever was detected by the energy company’s investigation.
.jpg)