The phrase “river, stay away from my door” is more than just a song title to people who live in areas subject to floods. Instead, it expresses their fervent hopes, for, when Old Man River goes on a rampage, he is no respecter of property rights. He rises up over his banks and spreads himself over thousands of acres of land, impartially flooding mansions and share croppers’ cabins, mighty industries and crossroads stores, thoroughbred stock and wild creatures, fertile acres and waste land.
Technically speaking, a flood is a temporary unbalance of Nature that results when more water is supplied to the land, in the form of rain and melting snows, than can be absorbed by the land itself and vegetation, or retained in natural and man-made reservoirs. Actually speaking, a flood is one of the most terrifying aspects of Nature, comparable to hurricanes, tornadoes, tidal waves and earthquakes. But, unlike these other disasters, a flood reaches its peak more slowly, and its effects last longer. Of course, in the case of flash floods of the West, the crest sweeps swiftly out of a canyon and is soon gone. But, in floods over great river basins, it may take several days for the water upstream to reach the lower part of the river.
Hurricanes approach rather slowly, too, but move on, while the flood waters remain for days and weeks. As the flood sweeps down from the headwaters, anxious eyes watch the river rise higher and higher, as inch by inch the swirling water climbs up the river. Now it passes the level that marked the crest of last year’s flood. Now it approaches the mark that formerly represented the all-time high for the river. Will the waters never stop rising? Will the levels hold? Can the dams keep back a part of the swirling, muddy waters? Can any barrier, natural or man-made, withstand the pressure of that roaring torrent?
There is relentlessness in all the wilder aspects of Nature-in the whirling cone of the tornado, in the greater sweep of the hurricane, in the sullen rumble of the earthquake. Man has mastered many forces on this earth, but he still stands helpless in the face of floods, storms and earth tremors. No power in the world-not even the atomic bomb-can break up a hurricane. No power can keep the rain from falling. But man can control the courses through which the rain-fed rivers flow. Of course even this control is not infallible. Levels will break. Dams will go out. Rivers will leave their old beds and cut entirely new ones for themselves, regardless of political or property lines. While he cannot control them, man has learned to anticipate hurricanes and freezes. He knows when weather conditions are ripe for forest fires, and he also is able to forecast floods.