A delta not so far away

Up here near the Mississippi River’s source, I don’t necessarily feel connected to the river’s mouth, a weird and exotic place about 850 river miles away.

Cypress trees, Mississippi River delta

But Dr. Chris Paola, a University of Minnesota geologist, feels the connection every day. He works tirelessly on a plan to restore part of the troubled Mississippi River delta, and he does much of this work in our neighborhood river lab, a muskrat lodge of a building that sits within sight of one of the very reasons the delta is troubled: a dam.

The Mississippi River delta is disappearing. The whole coastal region is very slowly sinking and there isn’t much we can do about that — just as we can’t do anything about mountains rising.

But we also hold back about half of the normal sediment with the dams we’ve built on the Mississippi and Missouri rivers. And that leaves the delta looking like a scrawny bird’s foot.

The loss of the delta and its wetlands is a fairly big deal, and poses more danger to hurricane-prone New Orleans than the failure of dikes, Dr. Paola says.

He and other scientists are suggesting that we abandon the outer reaches of the existing delta — can’t be saved anyway — and divert the river’s sediments to build a buffer of wetlands closer to the coast. His research includes building little, experimental deltas in the lab.

Experimental delta at St. Anthony Falls Laboratory

He also travels to Louisiana to study a robust, not starved-to-death, delta just west of the Mississippi delta.

Wax Lake Delta, Louisiana

I hope that his observations of both experimental and real deltas will help us figure out what to do about the pesky problem of hurricanes bashing into New Orleans and drowning it. This is a task of such magnitude, it would guarantee a lifetime of insomnia for me. I’m glad I’m not doing it. The political questions alone!

“There’s no physics that’s even remotely comparable to the complexities of Louisiana politics,” Dr. Paola said. What a comparison. The missing and mysterious dark energy of the universe could very well be in Louisiana.

We have two dams right here in southeast Minneapolis, the Upper and Lower St. Anthony Falls dams. And we still remove sand from the river bottom to deepen the channel for commercial navigation. I asked Dr. Paola where all that sediment went — it certainly doesn’t make it to the delta — and he didn’t know. He’s busy doing other things. So I looked into it. I’ll save that for next week’s post.

In the meantime, here are a few more photos from the Mississippi delta, which I took a few years ago. Oil refineries and ships right next to exquisite marshes loaded with birds. The whole area still looked a little battered from Katrina.

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One Response to A delta not so far away

  1. Anna says:

    Compared to the Mississippi, the Wax Lake Delta looks so much more…fed. Nice photos!