The area where the Mississippi River meets the Gulf of Mexico is one of the most engineered places in the country. For two centuries people have drained marshes, rerouted the river and built about 2,000 miles of levees.
The result has been destruction from hurricanes and land loss. Many experts are now saying (and some have been for awhile) that the only way to save the Louisiana delta and the people who live off of it, is to finally let mother nature do her thing.
One of those experts is David Muth, the Louisiana state director for the National Wildlife Federation. On a float plane trip over the delta last month, I got to see exactly what he was talking about. Before human interference, the delta was in perfect balance: fresh water would come in from the Mississippi river and disperse through the marsh, dumping sediment and mixing with the salt water from the Gulf. In some areas Gulf currents would eat away land from the marsh faster than it was being built (this is called an estuarine system). But in other areas, when the river flooded, it would overflow its banks and dump an excess of nutrient-rich sediment into the delta, building land (this is called a deltaic system). The delta was ever-changing, growing in some places, receding in others, but it was balanced change.
Now, because we have channelized the river and cut off it’s ability to flood the delta with sediment, that balance has been knocked off kilter. The whole region has turned more saline (the water is saltier) and we’re losing land at an incredible rate — 35 square miles each year. Since the 1930s, an area the size of Delaware has disappeared into the Gulf.
So don’t let the complexity of the region or the gravity of the situation distract you from Muth’s point: Mother Nature got it right the first time. We need to step out of her way, de-channelize parts of the river, and let the delta balance itself out.