Nestled north of New Roads and Morganza stands an engineering marvel known as the Old River Control Complex.  This formidable structure, with a history spanning nearly six decades, comprises an intricate network of dams, channels, locks, and guide levees. Its primary mission: to maintain the Mississippi River on its current course and prevent it from diverting down the Atchafalaya River, a steeper and more direct route, according to this article from The Advocate.. The importance of this complex cannot be overstated, as it safeguards not only the local region but also the entire nation’s interests.

As the specter of climate change looms larger, the Old River Control Complex faces unprecedented challenges. To ensure its continued effectiveness, the U.S. Army Corps of Engineers has decided to conduct a comprehensive inspection and, if necessary, undertake critical repairs. The focus of these repairs will be the Low Sill Control Structure, a vital component of the complex that suffered severe damage during the historic flooding of 1973.

McMillen Inc., a construction firm based in Boise, Idaho, has been awarded a substantial $34.2 million contract for the construction of a steel dam. This dam will serve the crucial purpose of sealing off the Low Sill Control Structure, allowing it to be dewatered for the first time since 1987 in preparation for the planned repairs scheduled for the upcoming year.

Colonel Cullen Jones, the commander of the Corps’ New Orleans District, emphasizes the significance of this undertaking. He remarks, “By keeping the Mississippi and Atchafalaya rivers on their current courses, the Old River Control Complex infrastructure is critical to both the region and the nation. This effort to inspect and repair the Low Sill structure will help ensure the integrity and successful operation of the complex for years to come.”

Without the Old River Control Complex, the Mississippi River would likely have succumbed to the relentless forces of nature and redirected itself down the Atchafalaya River. Such a scenario would have left Baton Rouge and New Orleans bereft of sufficient river water for commerce and, further south of Baton Rouge, deprived 1.2 million people of the freshwater they depend on. Recent weather patterns have intensified the need for these repairs. A scorching summer and an extended period of drought have caused the water levels in the Mississippi to plummet. This dry spell follows more than a decade of recurring and prolonged high-water episodes along the lower river.

To safeguard New Orleans, the Bonnet Carré Spillway has been opened upstream on 15 occasions, with six of those instances occurring since 2011 and four between 2018 and 2020, including two openings in 2019. Further upstream, near Morganza, the river reached an all-time record height in 2011, necessitating the activation of the Morganza Floodway for only the second time in its history. While this measure protects Baton Rouge and New Orleans, it inundated 25,000 acres of farmland as it flows toward the Atchafalaya River, eventually passing Morgan City.

The Old River Control Complex, strategically located at the confluence of the Mississippi, Red, and Atchafalaya rivers, has been performing its critical function since the 1950s. Comprising three major features—the Low Sill, Overbank, and Auxiliary structures—the complex effectively maintains a 70/30 downstream split between the Mississippi and Atchafalaya rivers, derived from the combined upstream waters of the Mississippi and the Red River.

In conclusion, the Old River Control Complex stands as a testament to human engineering prowess, tirelessly safeguarding the Mississippi River’s course. As it undergoes much-needed repairs and enhancements, the nation can rest assured that this critical infrastructure will continue to serve as a bulwark against the unpredictable forces of nature.

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