INthe early days of the operation of the Reclamtion Act the principal engineering problem was the examination of irrigation projects and the selection for construction of the more feasible of these, modified by the legal requirements of geographic distribution. The local engineers of the service made preliminary surveys which were inspected from time to time by the cansulting engineers, until what was deemed the most feasible project presented by local conditions was whipped into shape and submitted to a board of experienced engineers for the purpose of determining its feasibility. A report of this board was submitted to the Secretary of the Interior and one by one projects were ,approved in all of the States to which the act referred, excepting Oklahoma, in which no . feasible project has yet been found. Construction began in the Carson Valley, Nevada, in September, 1903, and , soon, after in various other States, until the approved projects were all under. consideration. The construction work accomplished since. the passage of the act, up to December 31st, 1910, . is given in the table .. on page 148. The diversion of water for irrigation in the arid regions of the United States is not new, but has been in progress for over half a century. Through the efforts of individual and corporate enterprisf;, the smaller and easier projects have been mostly carried out-these usually involving the diversion of the natural flow of a small stream over a smooth valley adjacent. As the smaller and cheaper projects are developed and those involving heavier work are undertaken, the development becomes more and more difficult for private capital and less certain of profitable returns. At the time ot the Passage of the Reclamation Act these causes had greatly checked the development of irrigation enterprises by private investment, and the engineers of the service found the projects usually involved engineering construction of considerable magnitude and difficulty. More than three-fourths of the projects undertaken required the . construction of an expensive storage reservoir, and the majority also required the construction of expensive diversion dams, tunnels, aqueducts or other structures relatively difficult and expensive, and . often requiring a long time in completion. For example, the Roosevelt dam in southern Arizona, recently completed, contains over 350,000 cubic yards of masonry, and forms the largest artificial reservoir now in existence; the construction of this reservoir required the expenditure of nearly $300,000 in wagon roads alone, to make the region accessible and to replace public roads submerged by the artificial lake. The heavy cost for transportation also compelled the manufacture in the vicinity of the cement, lumber, brick and sand necessary in this large construction. The storage dam on Shoshone River in Wyoming is the highest dam in the world, and the Reclamation Service is now beginning the construction of a still higher dam in Idaho. The Gunnison Tunnel in Colorado, recently completed, is nearly six miles in length and was can- structed under extreme difficulties presented by the presence of hot water and gas in great quantities, and uhe shattered condition of the formations pierced. The contractor for this tunnel failed and the work was carried out by the direct employment of labor under the engineers of the service; it required nearly five years in construction, and an expensive storage reservoir must yet be built to permit the complete development of the lands under the project. Some projects require for their proper development a very broad and comprehensive study of conditions over a large water·shed, usually extending across State lines. A typical example of this kind is the North Platte Basin, where a storage reservoir has been completed which will store over one million acre-feet of water, and will control the entire flood of the North Platte Basin in years of ordinary flow. This reservoir will hold the water that would run to waste in the winter months, and also store the excessive-flood waves from melting snow in the months of May and June for use during tle late summer and autumn, when the natural flow of the river is at its minimum. The construction of this reservoir to about the capaQity above mentioned is indispensable to the complete development of the water supply of the North Platte River; its capacity is far above the need! of the government project now construded at a cost of about $3,000,000. The surplus storage may. be used in the development of additional projects in the' basin, and in completing the water .supply for similar private irrigation enterprises previously instituted. The far-sleing policy which prompts the construction of this ' large reservoir under these circumstances would hardly be feasible for private enterprise, which must assure itself of an early return at the invested funds; yet,;'such policy as that followed was absolutely essential f'r thc proper conservation of the natural resources/ The same principle holds true with the majJrity ;' of the larger projects undertaken. An ihteresting fact, incidental to some projects, August 12, 1911 SCIENTIFIC AMERICAN 147 is the utilization of the water power made available by the irrigation works for the increase of the water supply by pumping from underground sources, and more completely utilizing the existing supply by raising a portion of it to higher levels which cannot be reached by gravity ditches. On the Huntley project in Montana, the main canal reaches a point where topographie conditions require that it be dropped to. a lower level to avoid a long stretch of broken country; the power generated by the flowill1' water at this drop is utilized for pumping a portion of the water to an elevation considerably higher than the main canal, which it would not have been feasible to cover by gravity. This is accomplished by the device of “dry pumping” in which the flowing water, is : received in an inclosed casing containing a large machine which consists of a turbine water-wheel and a centrifugal pump combined as one machine, on one shaft, in one casing, and the water received is divided into two parts, one of which emerges from the turbine wheel at the lawer level and is thus used for irrigation, while the other portion is raised to a high level-much higher than the main canal-and used there for irrigation. On the Yakima project in Washington a similar result is obtained by a battery of 11 large hydraulic rams. On the Salt River project the power developed at the storage dam is converted into high-voltage electric current, and transmitted to the valley, where the fertile land greatly exceeds the water supply, and the latter is increased by pumping from a large number of wells distributed throughout the region where ground water is known to exist. In this way about 40,000 acres of land which could not otherwise be irrigated, is added to the area of the cultivated land. A portion of this pumped supply is utilized in relieving the needs of the Indians on the Pima Reservation, whose industry and worth, and whose urgent needs, have been so much discussed in the public prints. On the Minidoka project in Idaho a diversion dam about 50 feet in height has been built to divert the water upon the neighboring valleys, and about 80,000 acres of good land is thus irrigated by gravity. It is necessary to allow a large Quantity of water to flow past the dam during the irrigating season, for th( satisfaction of irrigation appropriations at pointe further down the strnam. This water is taken from the dam under a head of about 46 feet, and by means Df hydro-electric machinery is converted into electri( current and transmitted about 15 miles to the south-westward, where it is used for pumping water from the main canal to irrigate about 50,000 acres of land too high to be reached by gravity, This is Eome of 148 SCIENTIFIC AMERICAN August 12, 1911 Department of the Interior, United States Reclamation Service-Results of Redamation Work from June 30th, 1902,'"o December 31st, 1910. Project". ~ Arizona, Salt River........ Arizona California, Yuma . California, Orlnnd........................ Colorado, Grand Valley............, ....... . Colorado, Uncompahgre Valley ........... Idano, Boise..... ........., ...... Idaho, Minidoka... .............. Idaho, Snake River Stor. Unit................. Kansa", Garden City.......................... Montana, Blackfeet........................... Montana, Flathead......................... Montana, Fort Peck......................... Montana, Huntley.......................... Montana, Milk RivEr....................... Montana, St. Mary Stor. Unit ......” “” ,, . Montana. Suu River................... Montana-North Dakota, Lower yellowstone ... Nebraska-Wyommg, North Platte..... Nevada, TruCli:ce-Carson. New Mexico, Carlsbact ... New Mexico, Hondo. New Mexico-''cxas, Rio Gruwlc............ New Mexico-'l'exa!, Leasburg UlJir........... North Dakota, Mtssouri Rive!' Pumping Bu ford-'rrenton Unit..... , .. North Dakota, 'Villiston Unit Oregon, Umatilla................ Oregon-California, Klamath .......... South Dakota, Bellp Fourche......... Utah, Strawberry Valley............ Washington, Okanogan ..., .. , . . Washington, Yakima Storage Unit... Washington, Sunny,ide Unit ........ Washington. Tieton Unit ......... 'yoming, Shoshone , . , ............. Totals frrigable Lands, Acres. H1" 220,000 90,160 14,000 53,000 140,000 243,000 124,700 10,677 . 133,000 152,000 132,000 32,521 215,000 300,000 63,780 129,000 206,000 20,255 10,000 160,000 12,500 12,000 25,000 127,01l 100.000 60,000 10.000 loo.ooiV 85,050 155,000 8,085,643 1|| t-O S3 <M 150,000 16,000 14,000 ” 30.ooo' 128,00 101,000 2,000 19,000 2,500 28.805 7,80J ii366 40,17! 97,630 50,400 20,255 25,000 4,060 8.047' 17,282 3,400 47,49R 10;000 . U5;(X Area Irrigated Season of 1910. a 600 . ;5,OOi' 4,000 8,655 41.246 27,085 13,105 440 2,000 2,500 27,108 15,410 3,4lX' S^S iir 131,000 '700 24.000 33,377 11,000 2,000 i!, 8,195 4,'2 50 1,300 . 25,O 74 6,000 14,349' II. So 3 % >^ g » 1,284,000 46,000 . 170;000 53,000 350,000 8.400 3,900 1,(25.000 200,000 35,000 40,000 5:60 662,000 75,000 15^666' 91,600 i;oo . 45,006' 1,69; 852 293,391 I 4.568,500 CanalE. Miles. Capacities in Second-IBct. 32 12 83 12 8 2 2 7 90 42 25 10 “ 341 64 ... 1 12 9 62 5 3 25 1 19 3 15 12 2 54 17 23 41 150 2 30 26 12 In 12 18 19 44 79 25 2 24 34 65 349 81 7'0 86' 291 406 7 112 15 165 23 100 124 455 102 120 45 14 43 78 99 200 380 112 1GB Tunnels. I 26 11 68 10,980 33,314 ij''4 Z,t5c fR!" !)«l” 2,840 8' 3,29;' 1,::O( 12,014 :95 1O.963 19.246 the finest land in the West, and for about one-half of it the water is lifted over 90 feet by electric energy. The power used for this purpose is required, of course, only in the irrigating season, from April to October, inclusive, and during the winter months would be available for other uses, if any sueh demand existed; but as the community is young and little developed, there is little demand for power, especially when it is available only during half of the year. It happens, however, that this region is rather remote from coal supply, and efforts are being made to utilize the surplus winter current for heating the residences and business houses in the villages which are growing up on the project. This region promises to develop into one of the few where it is commercially feasible to use electric energy for heating. One of the cardinal principles of irrigation is that it must be accompanied by an early system of drain-. age, otherwise the application of water by irrigation is likely to produce injurious effects ' by the waterlogging of a portion of the land, and the consequen+. rise of injurious alkali from great depths to the surface, where it becomes harmful to vegetation. Often it is necessary to provide artificial outlets for th' drainage ditches with which each farm must be pr;vided; and it is, moreover, impracticable to plan these to the best advantage before the exact nature of the problem has been indicated by the effects of a few years of irrigation. The varying underground conditions in the matter of porosity are shown by the actual results of irrigation, and it then becomes fea,ible to provide a drainage in time to prevent serious injury.