THE IRRIGATION AGE. 



apparently on quite secure footing, with strong proba- 

 bility of a vigorous and successful future under new 

 management. A number of small ditches have been 

 operated near Tucson for many years past, with good 

 results, though much larger works are now being 

 built by Allison Bros, to tap the underflow of the 

 Santa Cruz. 



THE FLOODING SYSTEM. 



On the upper Gila at Solomonville and near St. 

 John on the Little Colorado, as well as near Yuma on 

 the lower Gila, small ditches cover limited districts. 

 Very generally the plan followed by the American 

 irrigators is one of flooding the land by means of 

 small ditches at the upper side of the land to be ir- 

 rigated, the final distribution being accomplished by 

 means of borders 15 to 25 yards apart, between which 

 the water is successively turned, until the whole field 

 has been wet. This is repeated when necessary. An 

 amount of water equal to 18 inches deep covering the 

 land in crop is ordinarily enough for annual crops, 

 but perennial field crops, as alfalfa, require at least 

 30 inches in depth applied at successive irrigations 

 during the year. For fruit culture a greater amount 

 is applied at a single time, by means of small trick- 

 ling streams along rows. This is retained by active 

 cultivation, which has also the effect of keeping the 

 soil well aerated. 



THE TANK SYSTEM. 



Some advanced horticulturists are now advocating 

 the tank system of irrigation, and are building bor- 

 ders around four or more trees, or an equal amount of 

 vineyard, designing to hold a quantity of water on 

 a separate block. The loss of facility in aeration of 

 soil will probably cause this system to be discarded 

 for perennial crop or orchard and vineyards, though, 

 as practiced by the Pima and Maricopa Indians, 

 for annuals it is quite successful, where the fields 

 have six months' time of fallow. 



PUMPING. 



Water is being pumped at Yuma, near Phcenix, 

 and at several other points in the Territory with 

 limited success under present systems, and the acre- 

 age so irrigated is as yet small. 



WATER STORAGE. 



The Florence reservoir on the Florence canal, 

 about 20 miles from the head, covering 1,800 acres 12 

 feet deep on the average, is at the present time the 

 only storage works for irrigation in Arizona. This is 

 deemed a great success. 



Many other eligible localities awaiting capital are 

 known, but so far little has been done even in ex- 

 ploration and surveying to ascertain what might 

 be accomplished in the conservation of the flood 

 waters of torrential streams having their source in the 

 mountain region, and debauching through mountain 



valleys and gorges to the plains below. These offer 

 all the physical advantages for successful places of 

 water storage. The rainfall of the pine and oak 

 timber region, covering a large portion of the eastern 

 and northern part of the Territory, is over 20 inches 

 per annum, and of this an unusually large percentage 

 is runoff, from the fact the mountains are quite pre- 

 cipitous, making the need of reservoirs much more 

 urgent. Along the Gila and Salt River valley region 

 there is now a ditch system capable of extension to 

 cover a very large additional area of easily irrigated 

 land of good quality. This would make the distri- 

 bution of reservoir water easy and quick to accom- 

 plish, especially so as there are already large and 

 thriving settlements of farmers to draw settlers from. 

 For the investor of capital this is a most promising 

 field. 



The area of good land which might be reclaimed 

 under a system of reservoirs, in southern and western 

 Arizona, would reach into millions of acres. As to 

 the amount of water available there is every season a 

 sufficient quantity of flood water, if conserved, to 

 cover an acreage far in excess of the total now 

 cultivated. 



NEW OPERATIONS. 



Operations have been commenced on the Agna 

 Fria, near Phoenix, on Bill Williams' Fork, on Cave 

 creek, and by the South Gila Canal Company, with 

 a view of extensive works for storage of irrigation 

 waters. Several others are projected on Salt River 

 the Gila, Rio Verde and Santa Cruz. 



There has also been some consideration given to 

 several places where there is often flood water at 

 points favorable for storage not on any streams, but 

 to catch the drainage of large valleys. These valley 

 sites present some features of considerable advantage. 



UNDERFLOW. 



From the natural conditions of surface configura- 

 tion, Arizona presents an interesting region to study 

 this subject. 



Arizona has been termed over-drained. This is 

 true in the northern plateau region, bordered at the 

 north by the Grand Canyon of the Colorado, which 

 reaches a depth of 6,600 feet. On the Arizona side 

 many deep and narrow canyons drain off all water rap- 

 idly. This leaves large districts without accessible 

 streams of water, though in a region of comparatively 

 abundant rainfall. 



Through the central and eastern part are heavy 

 ranges of mountains, cleft in deep canyons and 

 mountain valleys, which at an elevation of about 

 2,000 feet widen out to large and fertile plains, with 

 isolated ranges and peaks. 



Many smaller streams, when reaching the valleys, 

 sink from sight during most of the year, and appear 



