Ground Will Shake and Snakes Will Flee as the Mississippi Drains

(Bloomberg) -- I was on site in 2011 when the Army freed the Mississippi from a man-made barrier and unleashed it into a large swath of rural Louisiana -- a harrowing trade off that flooded homes and farms to avoid catastrophe in New Orleans and Baton Rouge.

Now, rising river levels due to unrelenting rain mean the long dam-like structure known as the Morganza Floodway may be opened again for only the third time in history.

When I went into the bays the day before the barricade was lifted the last time around, the Mississippi squirted through cracks and gaps at the edges of the spillway’s gates. If the river had blasted through at that moment, it would have meant instant death.

The next day -- with me watching a safe distance away -- the Army Corps of Engineers used its giant cranes to open the bays for the first time in almost four decades. The ground shook and water shot out at least 40 or 50 yards. In a few minutes, the surrounding pasture below the Morganza flooded. Rabbits, snakes, toads and mice ran up the hill without any fear of humans. They ran over my feet and between my legs. Large fish trapped in the deluge flew through the air.

Three reporters had posed for a photograph next to a measuring post before the gush began. The next day, I returned to see that entire plain was flooded by then, and water was pouring into central Louisiana.

Nearly three quarters of a mile long (just over a kilometer), the Morganza structure was built in 1954 and can send 600,000 cubic feet per second of water through its 125 bays. It’s a tool in the Army Corps’ box that’s used to harness the river system that drains 1.2 million square miles of North America -- all or parts of 32 states and two Canadian provinces.

Unrelenting storms and rainfall over the past several months have increased river levels, raising fears that the Mississippi will flood over the top of the Morganza and render it useless. The Army Corps estimates letting 150,000 cfs through the gates should keep it from being swamped by the rising river. They may be opened by June 2.

In 2011, there was speculation over whether the Army Corps would be able to close the structure once it was opened. When the water finally ran down weeks later, the Army began to close the Morganza off.

In rural Louisiana, land owners and farmers get an annual notice that this might be the year the Army Corps has to flood their land. Many homes in that part of the state, as well as a big chunk of the Interstate 10, are up on stilts. Others, along with many fishing camps, are closer to the ground. Owners cut holes in the walls to give the water a way to enter and leave without ripping down the entire structure.

Devastating Floods

River experts say the Mississippi wants to flow down the course cut by its neighbor, the Atchafalaya. Over the centuries, the Mississippi’s mouth has moved along the Gulf Coast. In the 19th century, a miles-long natural barrier created by fallen trees was cleared by humans, which had the unintended consequence of making the Atchafalaya larger, making it more enticing for the Mississippi to take over.

After devastating floods in 1927, the Army Corps was determined to prevent a recurrence. It built a collection of concrete, levees and spillways to control and direct the river -- a monument to the Anthropocene age. In recent years, the Army has kept the Mississippi from taking the shorter 142-mile route of the Atchafalaya to the sea rather than the current 315-mile path past Baton Rouge and New Orleans.

Today, the river is a beast that’s been leashed because we’re afraid of it and we need it. But sooner or later, it will probably bite hard.

As John Spring, the former mayor of Quincy, Illinois, told me during another flood: “You can’t control the Mississippi River. I have lived on it my whole life; I know the river always wins.’’

To contact the reporter on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net

To contact the editors responsible for this story: Tina Davis at tinadavis@bloomberg.net, Pratish Narayanan, Steven Frank

©2019 Bloomberg L.P.