I am not a big fan of levees, they strike me as an inelegant solution.
Consequently, I have not paid much attention to any arguments about
them. However, I have seen some arguments from people that one of the
reasons the levees were not improved was that enviro groups have sued
to prevent it. I cannot address this issue so I leave it to others.

Sorry, I thought I had posted this to the environment NG, Please
excuse me.