https://scienceforourcoast.org/pc-programs/coastal/coastal-projects/mrgo-mississippi-river-gulf-outlet/

MRGO was maybe a good idea once. The the unintended consequences overruled the benefits.

The message was simple: Mr. Go must go. In fact, it became the name of the MRGO Must Go Coalition, referring to the Mississippi River-Gulf Outlet shipping channel stretching from the Gulf to New Orleans’ doorstep. The channel was labeled a “hurricane highway” after Hurricane Katrina, blamed for funneling storm surge into the city. It was closed in 2009, but widespread ecological damage from the decades it was open remains due to erosion and saltwater intrusion. A major step was taken earlier this month in addressing that issue. Congress approved legislation stating the federal government must foot the bill for MRGO restoration work, seemingly ending a long dispute over who should pay. Amanda Moore, director of the National Wildlife Federation’s Gulf program, has been the MRGO Must Go coalition’s coordinator since 2009. She spoke to The Times-Picayune | The Advocate about the legislation’s importance. The conversation has been edited for length and clarity.

nola.com,

It’s an expensive restoration plan, estimated at $3 billion in 2012. Why is it needed?

The channel itself was built in the late 50s, early 60s. And it just did an incredible amount of degradation. The building of the channel itself destroyed tens of thousands of acres of wetlands just directly adjacent to communities in New Orleans and St. Bernard. And then it also just exacerbated erosion of a lot of really important areas, like the New Orleans East landbridge with the saltwater intrusion and just the whole change in hydrology. So, closure of the channel was a huge deal, because that helped restore some of the natural hydrology of the area. And now, it’s really, really important that we restore the wetlands that were impacted, and help shore up the shorelines from further degradation so that we can have more protection for communities and also restore the habitat that was out there.

Can you explain some of the changes that have happened since the closure?

When they did the closure, it was really great because they put it right at Bayou La Loutre bridge, which is a natural feature that the channel cut right through. That was a really major salinity change. It was a permeable rock dam, but even right when they did the rock dam, if you went on one side and tested the salinity and the other side, there was a major change in salinity on either side, right there at the rock dam. And then over time, we’ve seen a lot of great improvements in ecosystems. Oysters have returned in areas where they historically were. We’ve seen growth come out of some of those relic ghost forests of oaks that you would see down in St. Bernard. And then all the way up into the Maurepas area you’ve seen cypress trees on the land bridge out there that really couldn’t survive before, but now the conditions are appropriate for them. So you’re just seeing a lot of really positive changes happening. However, you still have all that land loss.

Are there lessons about how these projects were done in the past in terms of putting certain interests above the interests of residents, whether for naive reasons or otherwise?

Even before Katrina, and before the channel itself was built, the community was very outspoken all along the way about what would happen if they built the channel, about what had happened when the channel was still open, and people were witness to what was going on. There was a group in St. Bernard that was especially vocal when they were considering building the channel, and everything came true. The worst fears came true of community folks. The channel was built before NEPA (National Environmental Policy Act), so things are different now. Hopefully something like this wouldn’t happen, because you have those processes in place to help safeguard and listen to the community. But I think there’s also lessons learned in the fact that the channel was just continually maintained even though everybody could see that there was a lot of degradation happening to the environment. There was no, ‘hey, we should do something different,’ or ‘we should look at this again.’ It was business as usual on maintaining that channel.

Normally I don’t post these Q&A but this is one explaining other posts I have done.

Repairing the damage from MRGO