The U.S. Army Corps of Engineers Vicksburg District is working to completely secure the Arkabutla Dam in northwest Mississippi following a depression discovered two years ago.
The depression was found near the toe of the dam in March 2023, prompting emergency actions to be taken to mitigate risk to the public. The initial phase of risk-reduction measures included lowering the pool elevation at Arkabutla Lake to 204 feet until long-term repairs are completed. Corps crews also installed groundwater monitoring devices and relief wells while automating the monitoring system.
Officials are now in the process of carrying out the second phase of remediation efforts. Crews are working on installing foundation grouting at the dam. This is to ensure immediate security while permanent corrective actions are being mulled by the corps.
According to corps officials, a dam safety modification study to determine the best implementable long-term solution is ongoing and expected to be completed sometime this summer. A tentatively selected plan has been identified and is pending final approval. This includes replacing the current deteriorated outlet works and constructing a new outlet works north of the existing one.
The long-term solution will be substantial and require lengthy design and construction periods, possibly up to 10 years, officials report. The reservoir pool is expected to stay at the target level of 204 feet until the project is completed, after which the pool levels will return to pre-maintenance levels.
As part of this process, an environmental assessment was completed under the National Environmental Policy Act of 1969. The assessment will be available for public review and comment from now until March 30.
Constructed in 1943, Arkabutla Dam is 65 feet high, 10,000 feet long, and reduces flood risk for 19,000 residents. The dam protects $510 million in homes and businesses.
