ARIZONA. SALT RIVER PROJECT. GENERAL STATEMENT. The principal data relating to the Salt River project are summarized below: Summary of principal data relating to Salt River project. Counties: Maricopa, Gila. Latitude: 33° 30′. Longitude: 112°. Townships: 7 north to 2 south, ranges 2 west to 14 east. Average rainfall: On drainage basin, 10 to 20 inches; on irrigable area, 3 to 10 inches. Estimated annual discharge of Salt River at dam site: 663,000 acre-feet. Range of temperature: Maximum, 120°; minimum, 20°; mean, Average elevation of irrigated lands: 1,000 to 1,300 feet. 70°. Principal railroads: Gila Valley, Globe and Northern; Santa Fe, Prescott and Phoenix; Maricopa and Phoenix. Nearest station: Globe, 43 miles from dam; Phoenix, 78 miles from dam, in center of irrigable district. Principal markets: Phoenix, Pacific coast cities, and eastern fruit markets. Irrigable area: 272,000 acres. Watershed area: 6,260 square miles above the mouth of Verde River. Reservoir area: 25.5 square miles. Capacity of reservoir: 1,284,000 acre-feet at elevation 220 feet above low water. Height of dam: 270 feet. Length of dam: 235 feet at river, 1,080 feet at top, including spillways. Type of dam: Masonry arch; gravity section from foundation. Power developed: 4,400 horsepower (at dam site); penstock tunnel, 620 feet. Ownership of lands: Private. Character of soil: Sandy loam, with clay in places. Value of irrigated land: $50 to $500 per acre, depending upon location. This project contemplates the irrigation of about 200,000 acres of fertile land in the Salt River Valley near Phoenix. This land lies. on both sides of the river and slopes gently to the southwest. There is a large district near Mesa and Tempe where the underground water is so near the surface as to be readily reached by pumping, and the installation of enough pumping plants to irrigate from 25,000 to 40,000 acres of land in addition to the area served by the reservoir will soon be under way. When finally completed the irrigation works will consist of the Roosevelt dam, impounding 1,300,000 acre-feet of water; a large diversion dam at Granite Reef, about 30 miles above Phoenix, to divert the combined waters of the Salt and Verde rivers into the canal systems of the valley; pumping plants, for which power will be generated at the Roosevelt dam and at various points along the canals and Salt River; and a complete system of main and distributing canals and laterals. Part of these works are already finished and in operation. On account of the great distance of this project from the railroad and centers of population, it was necessary to do considerable preliminary work in order to enable operations to be carried on properly. In order to afford proper means of transporting materials and supplies it was necessary to build a wagon road from Roosevelt to Mesa and from Roosevelt to Tonto, and a logging road from Roosevelt to the sawmill. It was also necessary to erect proper office buildings and cottages for the engineering force, warehouses for the supplies and equipment, and corrals and stables for the animals. A system for providing a water supply has been installed and a refrigerating plant has been erected. Other structures that have been necessary for the proper prosecution of the work include a telephone line, sawmill, cement mill, rock-crushing plant, machine and blacksmith shops, and a power plant, comprising canal, dam, electric machinery and penstock tunnel. The greater part of these structures were built prior to the period covered by this report and are described in previous annual reports. Additional details concerning those on which work has been carried on during the last year are given below. A general view of the works at Roosevelt is given in Pl. I. In the following table are listed the contracts entered into for building work on the Salt River project. This list includes all contracts for excavation, embankment, masonry, and erection of structures, but does not include materials such as cement, steel, timber, etc.: Contracts for building work on Salt River project to June 30, 1906. The general description of this dam and bids for building it are given in the Third and Fourth Annual Reports. Since these reports were published the proposed height of the dam has been increased 10 feet, thereby increasing the capacity of the reservoir to 1,300,000 acrefeet, or nearly 20 per cent. This addition to the height of the dam will increase the total quantity of masonry to 340,000 cubic yards, an increase of but 13 per cent. A Leschen aerial tramway, 1,700 feet long, has been installed for the purpose of taking the cement from the mill and delivering it at the contractor's stone crusher and concrete mixing plant, near the south end of the dam. This tramway will also handle the sand, which is to be crushed limestone from the quarry and crushing plant operated by the United States midway between the cement mill and the dam. In November, 1905, after the contractors had done considerable work on the temporary dams and flume, there occurred the largest flood on Salt River since 1891, the river rising about 25 feet in one U. S. RECLAMATION SERVICE FIFTH ANNUAL REPORT PL. I ROOSEVELT, ARIZ., LOOKING DOWN THE SALT RIVER FROM WITHIN THE RESERVOIR SITE, SALT RIVER PROJECT, ARIZONA, MARCH 6, 1906. U. S. Reclamation Service headquarters on the hill to left; main street of Roosevelt along the low ground; cement mill on hillside in center; dam site just within canyon; contractors' camp on hillside to the right. |