SACRAMENTO VALLEY PROJECT. 



its fertility rotation in crops is necessary. This, however, is impossible 

 without irrigation. Comparatively little progress has been made in irriga- 

 tion, though probably 2,000,000 acres will ultimately be irrigated in this 

 valley. The Interior Department, through the Reclamation Service and the 

 topographical branch of the U. S. Geological Survey, is now engaged in 

 collecting facts upon which to base plans for irrigating this vast area. The 

 work includes the determination of stream flow, the survey of reservoir 

 sites, the designing of dams and other irrigation works, and the survey 

 of the floor of the valley. The State of California has been co-operating with 

 the Federal Government and has furnished some of the funds necessary 

 to carry on this preliminary work. 



The drainage basin of the Sacramento River contains approximately 

 26,000 square miles. The estimated mean annual run-off from this 

 area is nearly 26,000,000 acre-feet, or almost sufficient water to cover 

 the entire valley 10 feet deep. 



The run-off from the watershed of the Sacramento River at Iron 

 Canyon above Red Bluff for the months of January to April, inclusive, the 

 four months of greatest discharge during a period of nine years ending with 

 1904, was 5,420,000 acre-feet, or 55 per cent, of the mean annual flow. The 

 discharge from May to September, inclusive, the five months when there is 

 the greatest need of water for irrigation, is less than 24 per cent of the total 

 annual flow. 



If the entire valley is to be irrigated, these facts emphasize the import- 

 ance and necessity of storing the flood flow for use during the irrigation sea- 

 son. Numerous reservoir sites have been surveyed for this purpose. Those 

 presenting the greatest advantages for economic construction which have 

 thus far been estimated upon are: Guenoc, Clear Lake, Indian Valley, 

 Briscoe, East Park, Millsite, Big Valley and Iron Canyon. From these eight 

 sites the annual summer flow of the Sacramento River can be increased 

 during the latter part of the irrigation season by more than 1,500,000 

 acre-feet of water, at a total cost of $5,800,000, or at the rate of $3.76 per 

 acre-foot for construction of storage works. Liberated during the months 

 of July, August and September, this would increase the flow of the Sacra- 

 mento River and its west side tributaries by about 8,000 cubic feet per 

 second. The low summer flow at Red Bluff is 4,000 second-feet. 



In addition to the above reservoirs, six reservoir sites of large capacity 

 are being surveyed during the present field season. 



These reservoirs could be so constructed and regulated that, in addi- 

 tion to their value for irrigation purposes, they would play an important 

 part in retarding the flood waves that have been so destructive to levees 

 and crops in the lower Sacramento Valley, and materially lessen the cost 

 and difficulty of reclaiming the overflowed lands, which exceeded 600,000 

 acres in 1904. 



A board of engineers from the U. S. Corps of Engineers has been ap- 

 pointed to continue the study of the flood and overflow conditions and 

 navigation problems of the Sacramento River. It is hoped that this work 

 can be carried out in some such way as similar work is being done on the 

 lower Mississippi River. 



Until the topographic and soil surveys of the valley are completed, it 

 will be impossible to give the location of the canals, the amount of land 

 that can be irrigated, or the cost of the Sacramento Valley Irrigation 

 Project. Because of the large area of fertile land; the large water sup- 

 ply; the great number of high priced products that can be grown; the 

 good transportation facilities; and the nearness to market, this project 

 presents the greatest opportunity for irrigation development to be found 

 in America. When the high valley lands above the zone of overflow have 

 been provided with irrigation systems and the swamp lands reclaimed 

 and irrigated, it is believed that the Sacramento Valley will be capable 

 of sustaining a population as great as is now being sustained by the entire 

 State. 



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