Phil and the rest: Lake Pontchartrain is not a closed system. It is open to the Gulf and is subject to tidal action. Therefore, water pumped into it will flow out into the Gulf. IF the integrity of the levees can be restored and the pumps got working, they will be able to pump the water out. I believe I recall hearing they can pump the entire city at a rate of about an inch per day. That would mean, of course, that it could take several months to pump it dry, assisted of course by evaporation and perhaps minimal absorbtion into the ground. Attached is a map of the Lake P. outlet.