What I am curious to know is if all that destruction can be circumvented and repaired without an extensive reengineering, all that water needs to be pumped, the soil stabilized, decontaminated and the river diverted.

Very simple solution. First....dig a humongous hole in the face of the earth that is visible from outer space. Second...pump out the water at the bottom of said hole whilst gassing up the Detroit Deisels so we all become millionaires "sooner rather than later"..