IRRIGATION IN ARIZONA.
Under the auspices of the United States government very important irrigation projects have been carried out. Under private enterprise, also, the area subjected to irrigation has been greatly extended. There still remain, of course, large areas that can be irrigated by the storage of the spring and summer waters, which is the plan being adopted in the Federal government works, and the climate and soil are such that the crops produced on these lands will make the expensive irrigation works profitable in the end. The industrial art of irrigation in the United States began in Arizona, and indications are found throughout the valleys of the Gila and Salt’rivers that large areas now barren and forbidding were once occupied by a numerous prehistoric race. The canals now in use in many places follow quite closely the lines of those ancient systems. These early ditches reveal engineering skill of a high order, and must have required an immense expenditure of labor. Their origin is lost, even in tradition, for they were abandoned as early as 1542, when Coronado visited these valleys in search of the “Seven Cities of Cibola,” but ethnologists date their operation as early as the eighth or ninth century. Portions of the beds of these ancient ditches are today utilised in modern systems. As yet little more than 0.3 per cent, of the total area of the Territory has been reclaimed. In 1902 the total number of acres irrigated was 247,250, an increase of 61,854, or 334 per cent., since 1899. The 781 systems represent a total construction cost of $4,688,298—an average cost per irrigated acre of $18.96. In 1899 the average cost per irrigated acre was $23.94. The decrease in average cost per irrigated acre in 1902 from that of 1899 is explained by the fact that the 1899 report included several systems, costing $900,000, which were not in operation in 1902. The well systems are included in 1902, but 648 were stream systems, as compared with 519 in 1899. Of the total irrigated area, 242,079 acres received water through 648 systems heading in streams; 1,061 acres were irrigated by springs and 4,110 acres by wells. The total construction cost of the stream systems was $4,591,570, an average of $18.97 Per irrigated acre; of the twenty-five spring systems, $6,766, an average of $6.38, and of the 108 well systems, $89,962, an average of $21.89.
