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40 WATER RESOURCES OF CALIFORNIA. equal to that required for irrigatmg crops on the same area Conse­quently any comprehensive plan for supplying water to all parts of the state in amounts suited to its future needs for urban and agricultural development, will have accomplished both purposes when all the present lands, classed as agricultural, are provided with an adequate allotment of water to irrigate their surface, and additional allowances are made for the dense urban development that will occur about the state s seaports. Of other uses for water, though subservient to the primary demands of the household and for growing food-stuffs, that of generating hydro­electric power to light and heat the homes in rural and urban communi­ties, to operate factories, railroads and car lines, to illuminate the streets of cities and towns, as well as to pump and deliver water tor the domestic and agricultural use, undoubtedly ranks close to the employ­ment for agricultural purposes. It is through these agencies that accessories to raising food-stuffs are supplied,, that farm produces are prepared for consumption, and the necessities and conveniences ol civilization are conveyed to all alike, so that a comprehensive plan to obtain the maximum use of the state’s waters must dispose ol t ese waters in such a way that a full measure of hydro-electric energy may 8,lso b© gp.Tip,T*fl.'flp,d. The agricultural lands of the state, situated on the lower levels, are favorably located to receive the flowing waters of the streams alter they have exhausted their inherent energy in tumbling down the steep moun­tain slopes. Three-fifths of the agricultural area of the state is less than five hundred feet in elevation, and seven-eighths of it is less than twenty-five hundred feet in elevation, while the mountainous water-producing region ascends to heights as great as ten thousand feet above the twenty-five hundred foot level. This spacious region, a steep and rugged country that spreads over half the state, yields practically au o California’s waters. These drain into the stream channels and flow past the bulk of the lower-situated agricultural lands in their descent toward the ocean. Thus, the region that abounds in the sheer declivities and swift flowing streams, most essential for the generation of hydro­electric energy, lies above seven-eighths of California’s agricultural lands and above those areas that will be m ostly. occupied by urban development. If the diversions of domestic and agricultural waters from the streams are generally confined to points below the twenty-five hundred foot contour, the areas most favorable for power developmen one-half the total surface of the state, with its waters nearly all of the state’s supply, remain intact for the unimpaired generation o f electric energy and these waters may then be re-used on the lower levels tor domestic, agricultural and industrial purposes. Therefore a compre­hensive plan to serve the maximum area of agricultural land with irriga­tion water, that makes its diversions o f' water below the twenty-nve hundred foot elevation and that provides additional waters for the growing urban communities about the seaports that are not spreading over agricultural lands, is the constructive measure that will enable the greatest use to be made of California’s water resources, and such a plan would give the greatest service to the primary needs of man an provide domestic and irrigation waters in their largest amounts, withou WATER RESOURCES OF CALIFORNIA. 41 particularly abridging the use of waters for the industries and the generation of electric power. "While the entire amount of California’s waters for an average year would submerge the twenty-three million acres of tillable land in this state to a depth of three and a quarter feet if evenly spread over and confined above them and the necessary application to the soil is but two feet in depth annually as a statewide average, still the disparity in location of these agricultural lands with respect to the sources of abundant water supply, presents insurmountable obstacles to the utiliza­tion of a considerable part of these waters on the lands that need them most urgently. In northwestern California lies the area most productive in water of all regions in the stated the North Pacific Coast region. Prom the evergreen slopes of its timbered mountains, more than one-third of all the state’s waters drain off into the ocean, passing on their course, only two per cent of the agricultural lands of the state. This immense volume o f water, enough to cover the arable lands of the entire state to an average depth of one foot every year, joins the ocean deep without opportunity of infusing harvest-maturing moisture into those portions of California’s soils that are too dry for maximum production without accessory supplies. The oceanward slopes of -the Coast Range are separated by more than one hundred miles from the nearest large body of farming land that is deficient in local waters. In attaining heights in an unbroken barrier of from four to nine thousand feet, the Coast Range Mountains effectively block the transportation of the waters from their western slopes to the extensive area of agricultural lands lying to the east and south. Only in projects of great magnitude can portions of these waters be captured and delivered, for use on the lands that need them. Diagonally across the state from this great waterproducing basin of the North Pacific Coast, lies a region in the southeastern corner of California, one-fifth the, entire area of the state, mountainous for a large part, but containing at least four million acres of flat lands of which the geography is only partly recorded because of the extreme aridity and uninviting aspect of its parched expanse. Some of the flat lands that skirt the edges of this moistureless solitude, have been fortunate in securing waters for their dry soils. These have responded to irrigation, and their great fertility has brought forth bountiful harvests to repay the pioneer. There were 546,000 acres of this region so irrigated in 1920. However, an area of 2,400,000 acres of the flat lands have been listed as agricultural, for water may ultimately be obtained for considerable areas in this region. Thus in one comer of California, one-third of its water resources are dissipated into the ocean with but small possibility of use, while in the opposite comer of the state, over six hundred miles distant, considerable areas of poten­tially fertile soils await the import of plant-nurturing waters to awaken their powers of production. _ Intermediate in geographic position between these extreme regions, lies the Great Central Valley containing three-fifths_ of all the agricul­tural lands of the state. The northerly part of this area, the Sacra­mento Valley, contains five and one-half million acres of agricultural lands and enough water courses through the streams traversing it, to