I got a few friends from college that work in LA with wetlands, at the Corps and at DNR. That is a story I have never heard about the levee projects being blocked by anything other than the lack of funding over the last 20 years. In fact watch for Retire Senator John Breaux from LA and watch what he is saying. He fought for over 20 years trying to get the levees improved to withstand a level 5 storm. Apparently they had the plans in the early 90s but the cost was sitting around 2 to 3 billion to do it and not one person would listen. Now it is going to cost 60+ billion to fix the problem. Breaux was a friend of the wetlands and pointed for years that the marsh south of New Orleans on the Mississippi Delta was dying and that saving it was the best protection that the engineers at the Corps. and the scientists could come up with to protect most of the communities to the south. Typically that is the debate over there. Some projects have been done that protected marshes from dying and started new deltas being built, but the commercial oystermen sued DNR and I know the case went to the Supreme Court. Just getting the researcher to agree what is best is almost impossible.
One story I heard about Breaux was that there was a meeting where they (scientist, government people, etc) were all arguing about what was best and this was the second or third meeting to go that way. He stood up said I am going home, but gentlemen, not one government employee, either federal or state is going home, if they want to still have your job, until ya'll can agree. Good Night. Apparently they all agreed within an hour.
The Corps says that each mile of marsh between the open water and where you sit reduces the storm surge by 1 to 1.5 feet. That is why the levees to the south held. However Lake Ponchatrain has always been a concern. I do not know about the gates but it is probably similar to what they said about the ones proposed on 2/3s of the rivers in Louisiana. The cost stopped the projects and most researchers said the storm would just flood across the marsh.
The government in Louisiana is probably leading the nation in trying to protect its wetlands. They have a coast wide plan called 2050 that is hoped to stop erosion along the coast by 2050. They are lossing an acre every 30 minutes to the Gulf. Every wedding or funeral that I go to with college buddies, we go drink a few afterwards and they talk shop. So I get to hear alot.
They have been expecting this problem to happen for a while. National Geographic had an article last year. Another article was in Scientific America about 5 years ago. A buddy emailed to me and it first paragraph starts talking about the city of New Orleans having nearly 10,000 body bags in storage in preparation for a direct hit from a hurricane. Apparently they expected the worst.
I expect we all will hear more from John Breaux. I liked him, a hunting, cussin, soft talking hard nail cajun, that understood what was needed.