The sentence that should be emphasized is that money for design and construction must come from Congress.
The Corps does what it can, but funds were cut during the Bush administration, and a divided Congress under Obama has done nothing but put important works on the back burner. Note that Parish officials did not blame the Corps, and are working with them.

Put Katrina in the filter to get all the BS threads on this sad story. No point in repeating it all, it is there for the few that might be interested.