Page:Popular Science Monthly Volume 87.djvu/94

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O subject of national economy has broader significance to-day than that of water conservation. Every one knows that unrestrained floods wreak yearly an enormous destruction of property. Our flood losses have, indeed, been computed at 200 millions of dollars per year. All are aware that the demands of power are contributing to the gradual exhaustion of our coal deposits, while the possibilities of deriving power from the flow of water remain at our grasp. A single water power of recent development has been estimated to effect a yearly saving of 365 thousands of tons of coal even at the very outset of its operations. Every intelligent conservationist, whether farmer, business man or student, observes that over the country-wide the soils are being impoverished by the wash of surface waters, and the fertile lands are being carried away to enrich the sea. If we seek figures again, we are told that one and one-quarter billion tons of silt are deposited annually in the Mississippi River, one half of which serves to impede navigation and the other half to extend the state of Louisiana out into the Gulf of Mexico. One who has observed the soils of the middle west in a state of productivity, and again the same or similar soils in the form of useless and rapidly broadening flats at the tip of the delta of the Mississippi, can not but be deeply impressed with the ultimate wastefulness of permitting the transfer of soils from a place where they are useful to a place where they are injurious.

If we view only the most obvious losses, we begin to realize the significance of water conservation; but still we may be far short of comprehending the magnitude of the forfeit that we regularly pay for an inadequate policy or practise with regard to our supplies of water. While agriculture, and consequently the flood supply of the future, may suffer from the erosion and leaching of soils, economists assure us that there are immense areas of farming lands which are diminished in production, because at the critical season they lack the moisture that might, with different methods of tillage, have been conserved in the soil from