An excerpt from my upcoming novel, Broken River 7.9, telling about When, not If, the Mississippi River changes its course

The Achafalaya captures the Mississippi

At the southern end of the Three Rivers Wildlife Management Area in Louisiana, water flows from the Mississippi River through the Old River Control Structure to join the Red River, forming the Achafalaya River, a “distributary” of a Federally-mandated thirty percent share of the Mississippi River’s water. Teacher Sheila Long pointed to the massive concrete dam alongside the river and explained its workings to her class of middle-school children on their special field trip from Natchez, Mississippi, forty-five miles north on the river road.

“Here the Army Corps of Engineers have built a great concrete dam reaching over a hundred feet down into the mud to hold the Mississippi in place. Only a portion of the big river’s water is allowed to flow into the Achafalaya River basin to keep the swamps flooded. If the big river had its way, all the water would flow that way and Morgan City would be the major seaport on the Gulf Coast instead of New Orleans.”

A small girl with thick glasses asked, “What holds the dam in place?”

“Rosie, I read that dams mostly depend upon their weight to hold them down and keep them from moving. They remain where they are built because of the friction between their base and the solid rock beneath them. But I also heard that the Army Corps of Engineers had to drive steel pilings into the river bottom to hold this dam where it is.”

In the Mississippi River basin there is no native bedrock, only semi-firm old river mud and sand saturated with ground water. The teacher had not read that in 1973 a massive flood had almost undermined the Old River Control Structure, nor that today the river ran high, just a foot below flood stage, and once again eroded the bottom at the foot of the structure.

Two minutes and forty seconds after the fracturing of the New Madrid fault had halted, a burst of seismic energy washed through the swampy flood basin. Sheila identified the funny feeling first and called out. “Hey, kids. Feel that movement? Somewhere, but not real close, there has been an earthquake, and we are feeling it shake back and forth right here.” The rocking motion continued. She frowned. “It sure seems to be shaking for a long time.” For seventy-five seconds the region lurched back and forth every second with forces between one-tenth and two-tenths the acceleration of gravity.

Her students laughed and Sheila worried as they ran stumbling across the dusty gravel of the parking lot back to their yellow bus. A subtle sloshing motion continued, but at a lesser intensity, for another minute, enough to keep the sand and mud in suspension in the liquefied soup that had been created beneath the old river channel.

The girl with the glasses stopped and stared. “Look, our bridge to the other side just broke.” One by one the others came to a halt. The students stood in the parking lot with their teacher and watched the slow movement of the Old River Control Structure, like a barge moving out of a lock. With no friction left to hold the concrete dam in place, the hydraulic forces of the big river simply pushed the dam aside as gravity buried it into the slush, pulling the steel pilings out of the liquid bottom. The big river flowed the way it pleased.

The victory by the Mississippi River that many called inevitable had happened, not the result of a flood but of an earthquake. Baton Rouge and New Orleans would soon sit beside a stagnant slough, cut off from the main river channel and the life giving flow of water needed to fill their shipping channels and support their factories and refineries.

On the other hand, Morgan City did not yet have the water channel to handle the huge volume of water headed its way. In time the flood would gouge a new course for the river and begun a new delta into the Gulf of Mexico. Along the way it would destroy all the roads, bridges, railways, canals, power-lines, and pipelines connecting Texas and west Louisiana to the Gulf Coast in the east.

Sheila sat in the driver’s seat of the bus, unsure of what to do. As she watched the accelerating flow of muddy water into the outflow channel, it seemed her world had come to an end. She explained to her class. “Kids, I don’t know how to get home.”