If this is true they need to send an engineer there promptly to dream up some way to plug the breach, quickly, if at all possible. Probably dropping lots of large pieces of concrete and loose rocks initially. Waiting until the pressure equalizes means waiting until that bowl is FULL, which pushes the date of everything else way back. This actually is more important and may save more lives than the individual rescue operations. Resources should be diverted as needed. If the engineers say the breach can't be plugged then send a little Dutch boy to do the job!
The only thing I can think of is to sink barges in the gap - that's the only thing ready to hand that would be large enough.
As soon as it was safe to go there they should have been checking the status of all the levees. You have to stop the city from bleeding to death before you can start to repair it. Alas, not all levee problems are fixable, but emergency repairs as fast and as large as hope permits should have been in their contingency plans.
If the engineers say the breach can't be plugged then send a little Dutch boy to do the job!
How about Joran Van der Sloot?
The problem is more water on TOP of dangerous flooding already. There is simply NO place for all the water to go.