USACE Activates MS Dam Emergency Repairs
On Tuesday (May 9), the U.S. Army Corps of Engineers Vicksburg District’s Emergency Operations Center identified a potential breach at the Arkabutla Dam on the Coldwater River in Mississippi.
According to the announcement, the district plans to lower the pool elevation to at least 210 feet to begin safe repairs and reduce breach potential. The operation is reportedly not expected to cause downstream flooding, and project personnel will continue to monitor the situation.
USACE notes that previously observed conditions led to the declaration, and the district will be providing updates as they become available. Several areas around the dam are also currently closed, and residents were warned to stay away as it is undergoing emergency repairs.
Additionally, the National Weather Service has issued a flood warning, noting that if the dam breaks, low-lying areas could be “severely affected.” Reports indicate that it is not clear how the potential breach in the dam could have occurred.
A theoretical disaster plan from the Mississippi Emergency Management Agency states that failure of the dam would lead to a “worst-case scenario” that would cost millions in damages.
Fears rise over potential Arkabutla Dam break: "It would be disastrous" https://t.co/eswITKIMnt— Newsweek (@Newsweek) May 11, 2023
“There's a lot of water coming down the Coldwater River that could cause possible flooding but according to the Corps of Engineers they are not projecting any flooding off of this event,” said Leron Weeks with the Tunica County Emergency Management Agency. “But I always tell my citizens always be careful and also just be aware of what's going on and everything. We are monitoring the river levels every day.”
The dam itself was constructed in the 1940s, spanning 11,500 feet in length and 67 feet in height. It was built in response to floods in the area, one of which being the Great Mississippi Flood of 1927. Each year around 2 million people reportedly come to visit the dam and surrounding area.
As of Wednesday evening, officials said that the failure of the dam is not likely. However, should that change, warnings will reportedly be issued for impacted residents.
US Dam Repair Costs
According to a recent report from the Association of State Dam Safety Officials, the estimated cost to rehabilitate the United States' non-federal dams is $157.5 billion. The cost to rehabilitate just the most critical dams is estimated at $34.1 billion.
ASDSO reports that the estimates were based on actual dam rehabilitation costs for non-federal dam repairs over the past 10 years and estimated costs for known upcoming projects.
This included nationwide cost data for more than 500 projects, including dam removals. Project costs ran from $10,000 for small projects to more than $500 million for large complex projects.
Rehabilitation, ASDSO explains, becomes necessary as dams age, technical standards and techniques improve, and downstream populations and land use change. However, the cost of rehabilitation can be high, and costs are reportedly rising significantly. The association attributes this increase to a combination of factors, including escalated costs for construction materials and labor, as well as the increased breadth of current engineering studies and analyses.
Additionally, the overall number of dams needing rehabilitation has increased due to the identification of deficiencies outpacing the completion of rehabilitation projects. Funding and permitting constraints contribute significantly to the slower rate of completion.
The report outlines that there are more than 88,600 non-federal dams in the United States. The number of high-hazard potential dams, where loss of life is probable should the dams fail, has increased almost 20% over the past 10 years to more than 16,000.
States reportedly regulate 70% of dams, while federal agencies regulate or own 5% of U.S. dams and the rest are unregulated. Approximately 65% of dams are privately owned, and about 31% are owned by federal, tribal, state or local governments. The rest are owned by quasi-governmental utilities or unknown ownership.
However, many dam owners cannot afford the high cost of dam rehabilitation and need grants and loans to rehabilitate their dams to reduce the risk of dam failures or serious incidents. The five states with the highest number of deficient dams, according to the study, are:
The full report, “The Cost of Rehabilitating Dams in the U.S.: A Methodology and Estimate,” can be found here.