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48 WATER RESOURCES OF CALIFORNIA. earth, work. It is so designed that by utilizing the storage capacity of Tulare Lake, the pumping plants along its course may operate eleven months in the year, resulting in a considerable reduction in size of canal and of pumps. The waters pumped during the winter months would be stored in Tulare Lake for use the following summer. No flood menace would be involved in filling the Lake during the winter with the comprehensive plan in operation, for the complete develop­ment of both the Kings and Kern rivers would absorb in their reser­voirs, the flood flows that occasionally fill this lake. In general, there is opportunity to generate ample electricity for the pumping required in the comprehensive plan, at the dams of storage reservoirs distant less than one hundred miles from the pump­ing stations. The total cost of these generating works would be very much less than the difference in cost between the canals and pumping plants of the comprehensive plan, and any gravity system that might be devised. The dam across Carquinez Straits would have many other advantages in addition to diverting the Sacramento waters into the lower San Joaquin River. During seasons of small stream flow, there is a ten­dency for the salt water of San Francisco Bay to work up into the network of channels that divide the rich delta lands at the mouth of the two rivers, into many islands. The dam below the mouth of these two rivers would prevent any damage to these fertile soils that might result from such occurences. Further, this dam would maintain Suisun Bay in fresh water and make it possible to profitably reclaim all the tidal flats along its margin, and bring unlimited quantities of fresh water to the manufacturing centers arising along the bay shore from Benicia and Port Costa easterly to Antioch. It would provide a. low level crossing for railroads and highways whose traffic now crosses Carquinez Straits on ferries. By constructing locks of adequate dimensions, this barrier would offer no obstruction, to navigation. It can be designed to afford ample water way for floods of the Sacramento and San Joa­quin rivers so that flood heights on the lower river will not be increased over those of the past. The practicability of locating and constructing such a dam below the mouth of the Sacramento and San Joaquin rivers, has been investi­gated as far as could be without exploration borings at the various possible sites for its location. It was concluded that a dam in this vicinity is feasible but that extended studies of all possible sites should be pursued before a selection is made. This dam would be of added value in creating a large fresh water reservoir in Suisun Bay and the delta regions that would have^ a stor­age capacity of 500,000 acre feet between the present levels of high and low tide. Supplies of fresh water might be pumped from here for consumption, after filtration, in the metropolitan areas of San Fran­cisco Bay, as well as for agricultural use to supplement the local sup­plies of the bay region. Thus water might be brought close into the bay region without cost of conduit from the distant sources. These investigations show that waters of the Trinity River and the three forks of the Bel River in the North Pacific Coast region, might be diverted into the Sacramento River drainage through tunnels under the Coast Range Mountains, not prohibitive in expense if their waters ? \ WATER RESOURCES OF CALIFORNIA. 49 are developed in large quantities. With these diversions effected, there would be plenty of water, in the Great Central Valley drainage area, to supply all its future needs as well as the requirements for all purposes about the San Francisco Bay region. The diversion for agricultural use from Suisun Bay would be by a canal leading southward through Ygnacio Valley. The water would be elevated m successive lifts into the Livermore Valley. A pumping WMEM slightly more than four hundred feet would be necessary to lirt the water into Livermore Valley and additional pumping would be required to distribute the water over all of its arable lands. A tunnel through the hills separating Livermore Valley from San Fran­cisco Bay would take this water into the Santa Clara Valley at an eleva­tion sufficiently high to permit gravity distribution to practically all lands o f this valley not irrigable from the waters of local streams. . agricultural areas of the • bay region to the north, would be irrigated from diversions from the .Bel and Russian rivers. Water would be carried m a gravity canal almost one hundred miles in length into the, Sonoma and Napa valleys to supplement their local supplies. Several hundred thousand acres of agricultural lands within the Sacramento drainage area, are isolated from the main body of its lands by the Sierra Nevada Mountains. The Pit River, in the north­eastern corner of the state, drains part of a great plateau region to the east of the Sierra Nevadas on the edge of the Great Basin of North America, and cuts through these mountains for a distance of sixty miles in a deep rock gorge to join the waters of the Sacramento River before they emerge into the Great. Central Valley. The agricultural areas of the Pit River lie in several parcels along its upper reaches and vary in elevation from 3000 to 5000 feet' above sea-level. The comprehensive _ plan provides for irrigating 263,300 acres of these areas by gravity diversions from the Pit River or i ^ tributaries. ? Seventeen reservoirs of varying capacity Will be required to equalize the stream flow for these diversions. P ACIFIC C O A S T D R A IN A G E BASINS— SAN FRAN CISCO T O S A N T A B A R B AR A C H A N N E L . Comprised within five larger valleys and several smaller ones, 890,000 acres of tillable lands lie along the Pacific Coast between San Francisco Bay and Santa Barbara Channel. Of these 135,000 acres are under irrigation at the present time. The water supply in the streams tra­versing these valleys is enough to cover their agricultural lands to a depth of two fedt in an average year, but the flow is so flashy that with unlimited storage, only two-thirds of their waters could be suitably equalized for irrigation use. Nevertheless, three-fifths of the total area can be irrigated under the comprehensive plan. In this plan the waters would be diverted from the streams in each valley and carried to the lands in gravity canals. The costly tunnels through the mountainous regions separating these valleys largely prohibit the importation of any small surplus waters that may occur in adjacent regions, so that the agricultural lands of each valley would be largely pendent systems. irrigat?e?d-- ?by.yj. ?inde­