Tuesday, May 17, 2011

Will the Mississippi River change course this week?

The Mississippi River pushed on a wall,
The American economy had a great fall,
All the king's money and all the king's men,

Couldn't put the River together again.

There's a slow-motion disaster happening in the US that could rival the Japan earthquake and tsunami for drama and impact. The Mississippi River is fighting the US Army Corps of Engineers.

This isn't just a flood, bad as floods can be. The Mississippi River wants to change course and the Army Corps is trying to stop it, as directed by the US Congress. The River will win eventually, and it could happen as soon as this week. Or it might stay put for 100 years. Stay tuned.

Why is this happening? The Mississippi River likes to move. As it nears the ocean, it likes to move a lot. The mouth of the river has jumped back and forth like a hyperactive kid when viewed from a geological perspective (see map at left). It's a natural process, so we shouldn't be surprised. But government and business leaders are often annoyed by natural processes and decide, in their infinite wisdom, to stop them. Sometimes it works...for a while.

But our success often creates a Humpty Dumpty problem, and now on the Mississippi we have to try to keep Humpty up on the wall. This time the wall is the ordinary-sounding Old River Control Structure, labelled "Low Sill Structure" in the picture above right. It's designed to keep the Mississippi River in it's place, but that's a tough job.

The Atchafalaya River will capture the flow of the Mississippi sometime soon, turning New Orleans, Baton Rouge, and the biggest port system in the world (by some measures)--the lower Mississippi River up to Memphis--into a shallow salty backwater bayou. The Atchafalaya River is shorter and steeper than the Mississippi River, and that's the way water likes to flow, the quickest route to the sea.

If you like this kind of story, and you like good writing, then you should really dig into John McPhee's fantastic piece on man vs. nature in the Mississippi River. Then, keep watching. This could be the biggest story of the year in the US, or maybe not. Depends on who wins this round of the fight. For good up-to-date info, check out the fantastic Wikipedia site on the Mississippi River flood of 2011, being updated in real time it seems.

Nature will win eventually, Humpty will have a great fall and then all the king's horses and all the king's men will run around like crazy people wondering what went wrong. John McPhee told them more than 20 years ago exactly what is going on.

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