The U.S. Army Corps of Engineers ceased hydropower generation last month at Narrows Dam at Lake Greeson, north of Murfreesboro in Pike County, to repair the structure that supports filters that prevent waterborne material from getting into the generator turbines.
Divers doing maintenance on the 1950-built dam discovered that the metal structure that holds the filtration system, called trash racks, had deteriorated. The Corps' Vicksburg, Miss., district office announced the closure pending repairs on Dec. 22.
The pause on hydropower generation does not affect the dam's ability to do flood control, as Little Missouri River water is being regularly released through its flood-control structure.
The news release said that optimal Lake Greeson levels for repairs had not been determined at the time of its publication but that the Corps would make every effort to minimize disruption to the use of the lake and river by visitors, partners and stakeholders.
A Corps spokesperson said Thursday that the district is determining the best method for repairs, scope of work, cost estimate and timeline.
She said the Vicksburg district is communicating about the situation with two Tulsa-based organizations: the U.S. Department of Energy's Southwestern Power Administration, in charge of hydroelectric generation at 24 Corps dams in Missouri, Arkansas, Oklahoma and Texas, and the Southwestern Power Resources Association, a membership organization of rural electric cooperatives and public power systems in those states plus Kansas and Louisiana.
The Corps primarily sells Narrows Dam-generated power to rural electric co-ops.
American Electric Power, a utility that serves part of western Arkansas as the Southwestern Electric Power Co. (SWEPCO), also serves as a market participant for Northeast Texas Electric Cooperative so that it can participate in the Southwest Power Pool, the Little Rock-based regional transmission organization that covers western Arkansas and operates, coordinates and monitors multi-state grids.
SWEPCO spokesperson Amanda Keeney said the company is not anticipating any disruptions because of the dam repair work.
"While all generating facilities will, at some point, take outages, the ability to participate in an RTO such as SPP ensures maintenance can occur while maintaining adequate and reliable supplies of power to cover customer needs," she said.
The Encyclopedia of Arkansas reports that the Narrows Dam rises 183½ feet above the river and that its powerhouse has three 8,500-kilowatt-hour generating machines -- the last one was installed in 1969 -- and that average annual power generation is 28 million kWh. As a point of comparison, Arkansas Nuclear One near Russellville produced 13.55 billion kWh in 2021.