re: State officials lose hope that Louisiana can reverse coastal land loss

Well bye bye plaquemines parish

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This was supposed to build barriers from waves and storms coming in and keep the land from washing away, along with holding sand and silt to create new land. Does anybody know if any of this ever happened?

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I remember tires for this project being around Grand Isle. Millions of tires were breeding grounds for billions of mosquitos. It didn't go over well, and never made it out of the staging process.

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The first one exaggerates the size of the coastal area by a good bit and leaves off facking Lake Pontchartrain, for starters

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If I recall, the picture on the left was the way Louisiana is sometimes represented on maps currently and historically. Whereas the right image is what would be accurate if you represent areas that are below sea level.

It's similar to the decisions not made post Katrina. We should limited rebuilding to certain areas. That would mean resources less stretched out. But no one has the political balls to do that.

Here, we need to cut our losses and focus on preserving what we have instead of this fantasy that not only can we protect everything, but that we could actually build new land. Again, no one has the political balls to tell people sorry, we can't protect you anymore. Thus, we will all suffer together.

Do you want to let New Orleans remain the main port by keeping the river there? Do you want the O&G exploration industry to thrive without getting in their way? Do you want the coast to be restored?

Choose one of those options, maybe two but not all three. Louisiana is under the delusion that it can have all three.

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There are over 29 locks and dams in the upper Mississippi River. These create pools where sediment can't be dispersed to a delta, which is exactly what LA used to be. We are no longer a high sediment depositing delta. I don't have anywhere for you to surf the web, but the definition of delta and what is in place on the upper Mississippi, along with the leeves should be suffice for you to understand. Edit: Forgot to mention the dams on the Ohio and Missouri rivers as well. There is no way to spin it, we're fricked.

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This sounds like it would make sense, but how is this not the case in the Atchafalaya/Wax Lake delta where the river flows freely and land is being created? There seems to be enough sediment to create land there, so why not south of New Orleans if the river was allowed to flow freely? The water flowing down the Atchafalaya comes from the Mississippi, so wouldn't these locks also affect the sediment load in the Atchafaylaya water where sediment is abundant enough to create land?

Yeah, there is still plenty of sediment coming down the river. But the sediment load is something around 20-30% of the historic levels. I'll try and find the exact number.

eta: numbers from the USGS survey on sediment loads.
Pre-1953 497 million metric tons
Post-1967 133 million metric tons 73% decrease, mainly due to dams and such on MS River tributaries.


Every little bit helps. The Coalition to Restore Coastal Louisiana ( CRCL ) and Lake Pontchartrain Basin Foundation ( SaveOurLake.org ) are always looking for volunteers.

CRCL had an event yesterday for a planting in Bayou Sauvage. Planted around 20,000 plugs of marsh grass in hopes to help reclaim I want to say ~40-80 acres of land.

People are confusing shoreline erosion (lateral direction) with loss due to sea level rise and subsidence (vertical direction). We could experience 0 shoreline erosion but lose a significant area of land due to sea level rise. What drives land loss today and what has driven it over the past century are the vertical processes, not the lateral processes.

Sea level rise predictions are now on the order of a meter over the next century. There are not enough dredges or river diversions feasible to combat that. We will be required to completely rethink our coastline and reengineer it.

Is the sea level really rising? I keep hearing about it, but if it were happening, wouldn't the media be having a field day over it?

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Not to mention river water is rough these days if not treated. All those chemicals and fertilizer from up north where they treat the river as s dump. There's a reason we have a dead zone off the dents every summer after the high river. Do we really want that diverting into the fragile land we have left?

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The effect is not enough to halt the annual low oxygen dead zone that forms each spring off the state's coastline. But the new delta, with its shallower open water areas intermixed with new islands and mud flats, provides refuge from low oxygen for a variety of fisheries, he said.

"The nutrient-rich water gets out and mixes with the warm salt water and you get an algae bloom that, when it dies and sinks, it sucks the oxygen out of the lower part of the water column," Macaluso said.

"But there's a misconception that everything in the dead zone is dead. Yes, probably a quarter of the water column (offshore) is depleted of oxygen because of the decaying algae blooms," he said. "But you don't see that in the interior marshes. You don't see that where you've got freshwater interacting in a marsh setting."

Just like in the Wax Lake area, that's true at the site of the controversial Caernarvon Freshwater Diversion on the east bank of the Mississippi in Plaquemines Parish.

Built to freshen outer wetlands along the parish to increase production on public oyster beds, the diversion has been blamed for low oyster production on privately leased state water bottoms closer to the river during years when it is opened to its maximum extent.

Critics have said increases in nutrients in those areas from the proposed diversions will add to those oyster woes.

But Macaluso says Caernarvon's operation is telling a different story. After water from the diversion enters the square-shaped Big Mar, "the next place that gets Caernarvon water is Lake Lery, and there are crab traps from one end of Lake Lery to the other," he said. "If there was a dead zone on the bottom of the lake, there would be no need to put crab traps on the bottom of that lake. There would be no crabs."

Kemp said the benefits of diversions extend to surrounding marshes and islands far away from their targeted land-building areas. He noted that around Atchafalaya Bay, healthy salt marshes and brackish marshes are being sustained by mud carried to the bay that comes into the bay from the outlet.

"So you have this big rim around the bays that is essentially keeping up with sea level," said Kemp.

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LINK

Based on the results that I just posted, it seems to me like the freshwater is mitigating that risk. Who could have ever guessed that if you just get out of the way and let Mother Nature do her thang that she would it better than anyone ever thought?