Going, Going, Gone: My Louisiana Coast Part 3

Catch up on part 1 and part 2

Water is a powerful thing.
If we control it, do we become more powerful?

I once felt the power of manipulating water.
And the shame over what I had done.

There was a creek in Mississippi I spent some time playing in.  In places, it was just inches deep.  In others--well I never found out how deep because we weren't allowed to go there.  Because I was the oldest in this particular group of kids, I often split away and did my own thing.  One day my thing was to gather up pebbles and stones from the creek floor and form mounds--levees.  I did this for a while, happily building away.  The next day when I returned to the creek, I noticed differences.  The water was deeper in places that hadn't been so deep.  Shallower in others.  Twigs and leaves had caught and trapped more twigs and leaves.  Water moved in a slightly different way.  There was a new little jag in the path of water.  I was amazed that my small bit of construction had such a powerful result.

It would be years later before I would look back on this and wonder if what I did ever caused any significant change.  Probably not, but I felt guilty just the same.

The Mississippi River is notorious for being walled in, shored up by levees.  Changed.  Controlled.

      When you ask a giant river to do unnatural things, when you ask it to stay inside impenetrable dikes all the way to the Gulf, then you get unnatural results: the entire estuary system starts to collapse and disappear.  But when you ask the river to simply do what it does naturally, you get different results entirely.  (Dr. Denise Reed, from Tidwell's Bayou Farewell)

The Mississippi River has always been a part of my life.  I grew up with this river practically in my backyard.  Before dawn when everything was still and quiet, I could hear the sounds of the river.  High clanging of metal chains as ships docked.  Low, mournful fog horns.  My great-uncle would take me down to the river batture (batch-er; the land between the river and the levee) to explore.  Sometimes my family took walks on the levee.  During my running days, my dad and I jogged on the levee.  It was always a treat to ride the ferry across the river.  Especially as a pedestrian rather than in the car.

This river is wide and deep once it hits NOLA.  It curves and snakes in such a way that the West Bank where I grew up is actually south of the river and falls east of many east bank locations.

This river, with her curvy, sinuous ways, is deceiving.  The surface usually appears calm, but I had been warned of her deadly currents and undertows since I was a child.  She's a siren.  Beautiful and seductive.  But hard to read and unforgiving.

Like any major river, the Mississippi is a wild woman wanting to move freely, flooding, jumping here and there carving a new route.  Not walled in by chunks of concrete and mounds of earth.

Like many other port cities, New Orleans as we know it wouldn't exist without the Mississippi River.  More importantly, New Orleans wouldn't exist without the levees holding the Mississippi in check.  In one place.  For all these years.

The river is a "land-making machine" (Richard Campanella from Gizmodo.com).  However, the The Old River Control Structure and levees that prevent the river from flooding and changing course prevent land renewal.

As a result the Mississippi River Delta is dying.

And there lies the problem.
Levees that stop delta renewal maintain the city and its progress--it's very existence.  Of course, the levees also save lives.
(Or at least they are supposed to.)

River control is one of the reasons there has been a 25% increase in wetland loss in the past five years (National Wildlife Federation).

One of the proposed solutions to this wetlands catastrophe is to build freshwater or sediment  diversions.  Water is diverted from the river out into marshland.  Sediment from the diverted river water would build up new land and maintain existing wetlands.

It is also thought that these diversions could help reduce the Dead Zone in the Gulf.  The Dead Zone--which is the size of New Jersey (Hallowell)--is an area severely polluted by excess fertilizers from agribusinesses.  The excess fertilizers cause algae blooms and lower oxygen levels.

Diverting fertilizer-polluted water through the marshes would reduce the amount of fertilizer running into the Gulf and, it is thought, would help fertilize marsh grass (Tidwell).

In graduate school, I studied fertilizer uptake by wetland plant species growing in artificial wetlands.  The idea was to encourage the greenhouse/nursery industry to install artificial wetlands to "clean up" their waste water for discharge, or (even more encouraged) reuse.

Yes, many wetland plants are capable of removing excess fertilizer in runoff water.  Some more than others.  Some plants are even capable of removing heavy metals.

But we're talking about artificial conditions.  Controlled amounts of fertilizer pollution running through a man/woman made wetland.

I won't deny that diversions help rebuild land.  The Wax Lake Delta region in the Atchafalaya Basin was built by a diversion.  The Caernarvon Diversion located south of New Orleans around St. Bernard Parish, built to boost oyster beds, has actually helped form new land through sedimentation.

But what kind of land is being built?

With more nutrient availability, it is highly possible, if not probable that marsh plants will grow shallow roots (why grow deep when food is in new sediment at the surface?).  Shallow roots don't hold on to marshland, especially during storms and hurricanes.  We could be back to square one after the next big one comes through and wipes out what these diversions built.

A study of diversion projects in Louisiana showed that they did not significantly assist rebuilding wetlands.  "...in the Caernarvon diversion, Hurricane Katrina destroyed the most vegetation in zones that received the most direct freshwater flow, even though these were far from the storm's path.  Most of the new plant growth that has occurred since the diversion was built consists of algae and other floating plants rather than the deep-rooted marsh plants that hold soil in place. This, says Kearney, is due to the influx of nutrients from agricultural run-off and industrial processes."  (Nature.com)


Are we back to square one by building these diversions?  Back to the days...replaying the days...of the Army Corps of Engineers controlling the environment with river control structures and levees?  Back to throwing around our arrogance and dominance?  Back to jacking around with Mother Nature?

 Is it a good idea to introduce who-knows-what kind of pollutants from the river into our already fragile marsh?  Is it a good idea to pump fresh water into a saline environment?  Both will alter habitats and the marine and plant life living there.

Fifty years down the road will this prove to be yet another environmental mistake?

Something HAS to be done.  I don't deny that.  But I don't know what that something is.
I don't know the answer.
I wish I did.

Read Part 4

Works consulted:

Gizmodo.com "The Mississippi River Is A Land-Making Machine: Dredgefest 2014."  

Hallowell, Christopher.  Holding Back the Sea: The Struggle for America's Natural Legacy on the Gulf Coast.  New York: Harper Collins, 2001

The National Wildlife Federation. "Gulf Coast Wetlands Rapidly Declining."

Nature.com "Wetlands Not Aided by Mississippi Diversions."

Tidwell, Mike.  Bayou Farewell: The Rich Life and Tragic Death of Louisiana's Cajun Coast.  New York: Pantheon Books, 2004.

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