Vicksburg, Miss. – The US Army Corps of Engineers Vicksburg District has extended the non-breach emergency at the Columbia Lock and Dam located on the Ouachita River approximately seven miles upstream of Columbia, LA. This declaration allowed the Corps to adjust water levels upstream and downstream of the lock and dam to investigate concerns while safely operating the structure for the navigation industry.
As part of the declaration, the pool above Columbia Lock and Dam was lowered by approximately three feet, while the pool below the dam was raised by approximately two feet. This adjustment began on 20 August 2024, and has been maintained at those levels throughout the investigation. As a result of the investigation, it was determined that pool levels will remain at the restricted pool levels until the stability of the structure can be guaranteed.
Interim risk reduction measure repairs have been made since the declaration, but additional exploratory investigations are needed to further evaluate the stability of the structure. Once the investigations are complete and data processed, the pool restriction will be re-evaluated. USACE’s initial timeline is to complete all investigations and data processing by next fall (2025). It is critical to understand that the pool restriction is based on the head differential between the upper and lower pool of Columbia Lock and Dam. As winter rains increase the flow through the Ouachita River, the upper pool will be allowed to increase as levels in the lower pool rise.
The change has not significantly impacted commercial navigation, and the lock has continued to operate.
Key Pool Details:
*Target Upper Pool: EL 49.0 ft-NAVD88
*Target Lower Pool: EL 36.0 ft-NAVD88
*Upper pool will be allowed to increase with the natural rise of lower pool due to increased flow through the Ouachita River.
The US Army Corps of Engineers appreciates the patience and understanding of the local community and stakeholders during this process.