Re: Compare and contrast
We have the entire Pacific to draw from, but TheIdiotsInCharge[tm] didn't start building desalination plants back in the 1960s ...
Santa Barbara completed a desalination plant in 1991 but mothballed it as the drought it was built during ended just as it was coming online. It is being reopened.
I have also wondered about moving flood waters around for use in areas that lack water. It would require coordination between states as well as some additional infrastructure to be built, but should be technically feasible. I wouldn't want to be the person trying to do the cost-benefit analysis, though.