A "study" of the levees was to have taken a few YEARS.
Only then, would construction begin, after more billions
was allocated by Congress.
Louisiana, of course, was utterly unable to spend any money on a STUDY itself, or on repairing its own levees; it had much more important things to do, like building a replacement for the Superdome, and a new convention center.
You are missing something. The levees need to be maintained continuously. A few years ago the same wind and waves would not cause the flood, but the levees were neglected recently.