Manton's World — John Russell Fearn

Randle Manton has brought the Earth back from the brink of nuclear disaster, painstakingly rebuilding a nearly destroyed civilization, even reaching out to space. But now he's told that the clouds covering the world will soon unleash upon the reeling planet yet another disaster: a great flood that will cover most of the Earth's surface. Despite his wealth, despite his great power, Manton knows that he'll only be able to save a fraction of humanity. Can mankind rebuild and survive yet a third time?