re: Our disappearing wetlands

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If not reversible - can it be slowed or even halted?

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You were right in the OP, it's all about sediment delivery.

Humans have chosen to live in a geologically dynamic environment. When they first got to this continent, this 'land' wasn't even here - it's all brand new, geologically speaking.

We were making sedimentary rock down here for a while which takes thin layers of sediment (sand, silt and clay) to be layed down regularly - like with spring floods. Then we cut off the sediment supply. Now the sediments previously laid down compact under their own weight.

In order to at least maintain current land levels, at least as much sediment would be required as would fill the area lost due to the compaction. This sediment would arrive in a slurry - otherwise known as a flood.

The culture we've developed generally trys to avoid being in floodways, and that so many have built homes on heavy concrete slabs at grade tells us that those sediment delivery systems would be undesireable. Ironic because the very areas that need the sediment the most are those that have heavy slabs sitting on compacting soils.

One more irony, levees. Many of the coastal communities build ring levees around their towns and pump the water out. This has the effect of de-watering the soils. Part of the subsidence, or soil compaction process, is having the weight of the soils squeeze out water. Dewatering the soils speeds up this process, and subsidence rates are greater within ring levees. If you look at an elevation map of south Louisiana, you can see all the towns surrounded by levees appear as depressions in the landscape.

To maintian our level of development down here would require far more planning and organization than we are prepared to dedicate. Eventually insurance will become unavailable, and people will begin to move out - except for those few who learn to adapt. Living in such a dynamic environment has its benefits, especially in a subtropical climate, diverse biology being one.

while your swilling all that DU beer what have they done? have you asked them?

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the river doesn't have a fraction of the sediments it used to have before all of the dams were built along it and it's major tributaries.

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This is true but the river still has a lot of sediment to build new land. I have seen it done south of Venice but the problem is that the land is dissappearing faster than it can rebuild. There has been a lot of new land created at the Atchafalaya Delta also. There just needs to be created a way to harness the river's sediment and to get it to other places. Most of the river's sediment goes out into the gulf off of the continental shelf. There also needs to be a way for these northern states to allow more sediment to come down here through the dams.

Don't get me started on studies either. It's one of the biggest wastes of money there is for the most part. With all of the money wasted on studies over the years, they could have started many projects. Even if the projects don't work, at least they could get actual proof and not theoretical proof. For example, they have been debating closing the west bay diversion south of Venice for years because they said it hasn't been working. My uncle kept telling them it was working. When it started out, there was 4-6ft of water in the bay. Now it's way shallower than that and some land was even created because of it. It's a small step but it's something. There needs to be tons more projects done like this throughout the state. My uncle's story is in the link below. John Snell did a few stories on him on fox 8.

West Bay Diversion Story

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With all of the money wasted on studies over the years, they could have started many projects.

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Why doesn't the public demand this shite to stop? It's ridiculous, I really wish people would start paying attention to what is going on around them. The money they are wasting is absolutely criminal.

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It's always upsetting to make that first fishing trip of the spring and on the way out to the islands notice all of the land that isn't there the last time you were out there.

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You should try being in the mapping business like I am.
I'm always doing historical photography research,sometimes all the way back to the 30's.
It will almost make you cry seeing how much things have changed in our marshes in the last decade there in those photos.

We should all just trade in our boats for surface drives now.

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The Red River carries twice the sediment as the Miss.

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Do you have a link for this? I'm sure it is possible. I just haven't read this before.

Just let the Mississippi avulse and travel down the Atchafalya and keep dredging the old channel to make New Orleans a port. Dump dreged materials out in the wet lands?

The lonshore currents are going to move new delta sediments westward anyway. So it's futile to build the coast in the east.
Maybe if they put longshore breaking structures then they could accumulate
sediment adding to the coast.

The real culprit here is sea level rise from the last glacial period. Coasts are dynamic and are impacted the most from these events. the

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JasonL79

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I have no link.
I read that on some site a couple years ago.

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MS River dumps 550 million tons of sediment into the GOM every year.

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I wonder how many acres this could translate into? I know we couldn't get all of it but even a fraction of that would be nice.