USACE lowers Ouachita River pool to reduce pressure on Columbia Dam

VICKSBURG, Miss. (VDN) — The U.S. Army Corps of Engineers (USACE) Vicksburg District will begin gradually lowering the Ouachita River pool above the Columbia Lock and Dam by about three feet this weekend. This drawdown is a precautionary step due to an ongoing structural issue at the dam, though there is no breach.

The river’s flow has been decreasing, prompting the need to reduce water levels to where they were in fall 2024. Recent spring rains had temporarily raised the river. Lower water levels will affect areas upstream from Columbia Lock and Dam to Felsenthal Lock and Dam, including the Monroe, Louisiana area. The pool at the Jonesville Lock and Dam, located downstream, will remain unchanged for now but is expected to be raised later this year.

No boat ramps are currently closed, and none are expected to close over the Fourth of July weekend. However, boaters should use caution—recent high water has left sand deposits at some ramps. Ramps typically remain usable until water levels fall below 49 feet; as of July 3, the level was 52.1 feet. USACE teams will work to keep ramps clear and safe during the drawdown.

This pool reduction is part of a risk management strategy after engineers found concerns at the Columbia Lock and Dam in August 2024. Lowering the pool helps reduce pressure on the dam by minimizing the difference between upstream and downstream water levels. High flows naturally equalize pressure, but during low flows, the difference grows—raising risk.

In low-flow conditions, USACE may also raise the Jonesville pool by up to two feet to help ease downstream pressure on the Columbia structure. That measure will become more effective as river levels drop further.

USACE will continue monitoring conditions and keeping the public informed.

For current conditions on the Ouachita River:

• USACE MVK Water Management – Ouachita River Report: https://wm.mvk.ds.usace.army.mil/ouachita.htm
• Ouachita River Navigation Current Pool Levels Graphic: https://wm.mvk.ds.usace.army.mil/plots/ouachita_structures.png