Of course, that's just necessary for the fancy economic development plan, not flood control. The Corps figured out how to handle floods without ruining anyone's property, but Project backers rejected that alternative because they want to remove the earthen levees that have long obscured river views. And how much of the value of those improved views are going to go to the people getting foreclosed on? Not much, I'd expect. Big businesses with influence on the city and county governments are going to collect a lot of those benefits.
What I'd like to see in this sort of situation is a sort of auction process. Present several options--the default flood cure with no economic improvements, the TRV proposal above, and some other ones with different neighborhoods selected to be the new flood plains. Offer a compensation package for the first neighborhood to vote in favor of being bought out. If nobody goes for it, the city can offer more--if this project is so valuable--and other proponents can put more money in the pot. Either a fair portion of the project benefits will go to the people being displaced, or the backers will have to admit that it's not worth doing at a fair price. Right now it's only moving forward because land is cheap when the government confiscates it.