There is one, and only one solution, and we have almost no time to try it. We must turn all our resources to repairing the natural world, and train all our young people to help. They want to; we need to give them this last chance to create forests, soils, clean waters, clean energies, secure communities, stable regions, and to know how to do it from hands-on experience.
Why is it that we don't build human settlements that will feed themselves, and fuel themselves, and catch their own water, when any human settlement could do that easily? When it's a trivial thing to do?
The value of land must, in the future, be assessed on its yield of potable water. Those property-owners with a constant source of pure water already have an economically-valuable "product" from their land, and need look no further for a source of income.
Freezing concentrates sugar (maple sugar), alcohol, and salt solutions as efficiently as heating distils water or alcohol from solutions. Open pans of maple sugar can have the surface ice removed regularly (each day) until a sugar concentrate remains. Salts in water, and alcohol in ferment liquors can be concentrated in the same way.
If you let people loose in a landscape and tell them to choose a house site, half of them will go sit on the ridges where they'll die in the next fire, or where you can't get water to them. Or they'll sit in all the dam sites. Or they'll sit in all the places that will perish in the next big wind.