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Show Chapter 9 Watershed Management WATERSHED MANAGEMENT is the foun- dation of a conservation and development pro- gram for soil and water resources. It is designed to maintain the productivity of these resources at not less than their present levels and to help raise those levels to meet increasing requirements. It is based on a recognition that land and water resources are interdependent and must be used so that each reinforces the productivity of the other. Watershed management is not a new idea. It is widely used in many other countries, and our failure in the past to use it more extensively re- flected the richness of our natural endowment and our relatively low population density. Watershed management has always offered the possibility of maintaining and improving the yield of any given acreage, and of protecting any stream. But as long as it seemed cheaper to move to new land than to apply watershed man- agement measures to old land, and as long as landowners were willing to destroy their land to reap immediate profit, its potentialities were largely ignored. Now new land is scarce, and population is growing rapidly. We can no longer afford to let our resources deteriorate. Further, as the center of population shifts westward, an increas- ing load is being placed on the watersheds in arid and semiarid parts of the West, where erosion is an extremely serious threat and where watershed management practices need to be adopted as an integral part of basin development. In their natural state, before settlement, water- sheds are covered with trees or grass, or are bar- ren, according to the inherent productivity of their soil, the amount of rainfall, the slope of the land, and other natural factors. Man's entry may set in motion forces which, unless they are counteracted, eventually destroy the usefulness of the land. Cutting trees, plowing and harvesting cropland, establishing industries which feed upon the land and pour their wastes into the streams- all these things use up the productivity man seeks to exploit. Seriousness of Problem The last general Forest Service survey, made in 1944, indicates that there is and has been for many years a net annual drain on saw timber. There is no prospect in the foreseeable future of bringing growth and drain into balance. It is claimed that for some years there has been an annual increase in the rate of timber growth, which is true. But increases in the growth rate are not necessarily related to sound forest man- agement. If an entire area is stripped of timber, then reseeded, the growth rate will be higher for the new trees than for those cut. But the yield will be zero for many years, and erosion may be so serious that reseeding is impossible. Other Forest Service surveys appear to show that the increase in growth rate thus far achieved is due less to good management than to the rapid cutting of large-diameter saw timber. Not only is the rate of growth being applied to a base which diminishes annually, but, as the young trees 123 |
