Mike, you are absolutely right about the very large area that has to be protected. But it's not so bad that three states are completely flooded by rainwater.

There are high grounds and low grounds if you look more precisely. And that's also the entrance for searching the way out of this problem. It's all about water-management on a small scale. So dividing the area in logical parts and then try to introduce Water-management.
Which means looking to the sewerage systeem, the distance to the sea, under or above sealevel, presence of dikes, dunes. The ability of the ground to store water in itself, is it covered up with houses,buildings, stones, roads etc. Is there a possibility to store water on fields with dikes, or lakes, etc. And is the danger coming from the sea or from the rain, or both.

Mike, you mentioned f.i. the people who build homes on the seashore. Well, ofcourse that should be forbidden . In Holland we have a lot of these zones where it is not allowed to build.

It's clear that there is no quick and cheap solution for this immens problem, but first the mentality has to alter from defeatism to protest and problem-solving on a small scale.

Mike, you concluded harshly that paying for all the repairs by taxes and Insurance might be better?/ more sensible then paying a lot of money for preventing the odds of these floodings.
Taking into account the growing climate change, I do not follow you there.