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Show times, and (c) bringing in irrigable uncultivated lands. Nearly one-half of the more than 4 million acres presently irrigated in the Central Valley is in need of supplemental water, and an additional area of from 3 to 6 million acres awaits life-giving water. The many uses which can be found for every acre-foot of water, even in irrigation alone, make it imperative to plan the most efficient use possible of the natural water supply of the basin. To this end reduction of every nonconsumptive disappear- ance of water should be sought. A reduction in evaporation losses through underground storage or other means will be an important consideration in planning. In addition to the construction activities, as new areas are brought under irrigation, farmers should be provided with technical assistance in land prep- aration, in laying out irrigation systems, and in planning and applying sound cropping and irri- gation practices. In many irrigated areas farmers also need technical help to improve present irriga- tion practices and make more efficient use of water. In both the new and existing irrigated areas there are needs for long-term credit to permit farmers to finance the installation of new or improved farm irrigation systems. Such measures will help to make the best use of primary facilities to be constructed. Power Electric energy in the Central Valley and the adjoining San Francisco Bay area is obtained from a system including both hydroelectric and fuel- electric plants. This combination is essential be- cause the hydroelectric potential is insufficient to meet power needs; characteristics of the stream flow are variable; and storage regulation must be pre- dominantly for irrigation and municipal purposes. Power loa.ds are steadily increasing as industrial activities expand, population increases, and irri- gation is extended to new lands. A balanced program for meeting these power needs will involve the further construction of both hydroelectric and fuel-electric plants. California has been favored with relatively large quantities of oil and gas, which are used to generate power. These reserves are exhaustible, and development of as much hydroelectric power as possible is desirable so as to conserve regional fuel supplies. Full economic development of potential hydro- electric capacity in the Central Valley should be sought. Municipal and Industrial Water Supply The San Francisco Bay area already is using most of its local water resources and is obtaining a large part of its supply from the Central Valley. Steadily increasing demands will have to be met largely from the Central Valley, with possible assistance from some of the northern coastal streams of Cali- fornia. Demands are increasing in the Central Valley itself. Provision for the expanding munici- pal and industrial needs of this area is therefore an essential element in the Central Valley program. Flood Control Under natural conditions, about one-fourth of the main valley floor of the Central Valley was sub- ject to annual or periodic overflow. All but a small portion of this land has been reclaimed through the construction of levees and is used primarily for irri- gated farming, but includes considerable areas of urban and industrial land. Many levees can be overtopped or breached during large floods. Tributary valley areas are in many cases unpro- tected from flood damage. Flood control reservoirs or storage capacity for flood control provided in multiple-purpose reser- voirs will protect downstream areas in the tributary valleys on which they are located and will con- tribute toward a higher degree of protection on the main valley floor. Additional flood protection is needed in many areas and should be provided to the maximum economic extent, for without ade- quate flood protection, both the rural and urban economy of the basin can be impaired. Navigation A ship channel has been constructed from San Francisco Bay to Stockton, and another is under construction to Sacramento. These are the two principal cities in the Central Valley which can be reached economically by ocean vessels. In addi- tion, the Sacramento River upstream to Red Bluff, the lower reaches of the Feather and Mokelumne Rivers, and the San Joaquin River and its distribu- taries in the delta have been improved for shallow draft navigation. The improved channels consti- tute a transportation network and also serve to carry flood flows, as well as irrigation water in transit 150 |