Temporary barrier to facilitate Thatcher Dam repairs

EL DORADO — The installation of a “poiree needle system” at the Thatcher Lock and Dam has set a temporary barrier to allow the U.S. Army Corps of Engineers to begin work to fix a leak that has resulted in low water levels in the Ouachita River pool above Thatcher dam.

Robert Reynolds, a volunteer advisor to the Union County Water Conservation Board, as well as the board’s founding president, said last week that the poiree needle system will hold the Thatcher pool above 71 feet above sea level, acting essentially as a temporary dam.

In October, a leak in the hinged crest gate at the lock and dam allowed the Ouachita River to begin falling to levels that could have potentially threatened the drinking water supply in Camden and impacted Union County Water Conservation Board infrastructure in Calion.

Camden residents get their drinking water from the Ouachita River via an intake system in the city, while Union County’s drinking water comes via the Sparta Aquifer. The Union County Water Conservation Board does, however, have an intake pumping system in Calion that draws water out of the Ouachita River for local industries.

Usually, the hinged crest gate would maintain the Thatcher pool water level at 77 feet above sea level. The permanent concrete dam structure prevents the pool level from falling lower than 71 feet above sea level.

A statement released by the U.S. Army Corps of Engineers last month said that once water levels fell to 71 feet and the hinged crest gate was exposed, inspections would begin immediately, with repairs following as soon as possible.

“With this poiree needle system, [the Corps of Engineers] can perform the work they need to with the current water levels, whether that’s 71 feet, 72 feet, 73 feet,” he said.

Several local industries use water from the Thatcher Lock and Dam, including Delek: El Dorado Refinery, the LANXESS Central plant, El Dorado Chemical and the Entergy/Union Power Partners power plant, which was built at the same time as the Union County Water Conservation Board’s infrastructure in Calion. Additionally, the new El Dorado High School, Mystic Creek Golf Course, Mystic Creek residential development and Holly Falls, a local wedding venue, use the river water for irrigation.