Six months? While the city is under sea level, shouldn't you be able to let out much of the water in the city just by breaching the upper part of the levee walls in a few places (after the initial storm flooding on the Lake and River have ebbed). It wouldn't let out the below sea level stuff, but it should lower the stuff above the first floors.
Walter said the city water pumps would be destroyed and will need fixing or replacement, so that's why it would take 6 months to pump the water out.
But I'm concerned with the oil and gas surface residue laying on top of the water. Could that catch fire?
sw