Polk County commissioners agreed on Monday, Aug. 20 to spend $18,800 on engineering reports on the Turner Shoals Dam at Lake Adger.
Polk County Manager Ryan Whitson said the N.C. Department of Environment and Natural Resources (DENR) requires the county to perform a dam failure analysis and develop an emergency action plan. The state also requires a spillway design flood (SDF) on the dam, which was built in 1925.
The county is hiring AECOM Technical Services for the engineering services.
The dam failure analysis and emergency action plan is estimated to cost $10,900 and the SDF is estimated at $7,900.
Commissioners approved a budget amendment to take the funding out of capital funding escrowed specifically for dam repairs. The county has been budgeting money every year for future dam repairs at Lake Adger, with $600,000 saved so far.
Commissioner Ted Owens said on Aug. 20 that the reports are something normal required by the state. It doesn’t mean the dam is failing, Owens said.
Polk County purchased the bed of Lake Adger in 2009 for $1.6 million from Northbrook Carolina Hydro, LLC for future use as a water source. The county leases the lake to Northbrook for $1 per year in order for Northbrook to continue operating its power plant located there.
Black & Veatch Engineers told county commissioners in 2009 that repairs the dam would need in the next few years could cost approximately $2 million.
Engineers said that potential problems with the dam include issues with bulkheads and the concrete of the dam. Studies done in 2009 concluded that if water were to rise over the top of the dam the structure would become unstable. However, commissioners said that water has never risen to the top of the dam in its history. Engineers agreed it would take a flood of Biblical proportions in order for water to spill over the top.
Polk is still awaiting approval from the state to reclassify the Lake Adger watershed as a class III watershed, which will affect Polk and Henderson counties. Henderson County has not given its support for the new reclassification and it is unknown when the state will approve the reclassification in order for Polk to move forward with using the water.
Once the lake has been permitted by the state as a water source, Polk will be able to pull a maximum of eight million gallons of water per day out of Lake Adger. The county has future plans to construct a water plant on property it owns at the county transfer station in Mill Spring.