their importance and urgent need of investigation the projects are ranked as follows: (1) A dam at the Yuma dam site, with canals from this point to lands in California and in Arizona. (2) A diversion at Black Point, near the upper end of the Blythe estate, in California. (3) A diversion at Headgate Rock above Parker, Ariz., with canal covering Colorado River Indian Reservation, in Arizona. (4) A dam at Williams River for storage purposes and water regulation. (5) A diversion at Bulls Head, Arizona, with canal leading to the lands of the Needles Valley, Arizona. Also a further investigation for bed rock at Bulls Head for a high dam for storage purposes. (6) Investigations of possible reservoir sites above 35° 36′, notably at the Las Vegas Wash and at Virgin River. It would be advisable to investigate reservoir possibilities on Colorado River in Colorado, Utah, and Wyoming, above the point where streams carrying high quantities of silt enter, so that we may have knowledge of such storage possibilities as exists where provisions do not have to be made for silting. YUMA DAM SITE. At a point 22 miles above Yuma, Ariz., Colorado River passes through the first rocky gorge, the walls being about 1,500 feet apart. The hills through which this gorge is cut were named the "Purple Hills" by Lieut. J. C. Ives in 1857-58. The topographic maps show that the construction of a diversion dam here, 70 feet high, would make practicable the reclamation in the river bottom of 178,000 acres in Arizona and 23,000 in California, with a possibility of so extending the California canal as to cover all the lands of the Salton Sink, where it is roughly estimated there are about 300,000 acres of good land not now under ditch. The 23,000 acres in California are fertile lands in the Yuma Indian Reservation, on which there are about 300 Indians. The reservation has recently been subdivided; the lands will be allotted to the Indians in severalty, and the remainder made available to settlement. This project is the only one which has so far been discovered where a high-line canal is considered worthy of investigation, if satisfactory conditions are found at the proposed dam site. Of the Arizona acreage 87,000 acres are mesa lands, which could be devoted to the highest forms of agriculture, the remaining 91,000 acres being bottom lands suitable to general agricultural products. The advisability of constructing a high-line canal can be determined only by further investigation. The general plan of reclamation of the lands adjoining Colorado River, as proposed by A. P. Davis, supervising engineer of the Reclamation Service, provides that the project farthest down the river should be first taken up, and diversions made and reservoirs formed as needed, the dams being of such heights as to permit the silting of low bottoms, which could afterwards become agricultural lands by diverting from lower outlets in the dam. The building of the Yuma dam or a low weir is in harmony with such a plan, and has independent intrinsic merit of the highest order. The extreme upper waters of the reservoir would cover the lowlands between Picacho and Ehrenberg, but would not "drown" any large amount of land at present suited for agriculture. The desirability of extending the work along the lines proposed by Mr. Davis is dependent upon further study. The project of a high dam is dependent on finding bed rock at this dam site within reasonable depths. If such conditions are not found, an estimate will be made upon a low diversion weir with a spillway on bed rock on the side and a low-line canal. This lower project is conveniently located for transportation facilities, and would reclaim lands which now have a growing market for their produce. Furthermore, the construction of the system here proposed would aid a number of most deserving citizens of the United States the farmers below Yuma, who are now struggling with defective irrigation and reclamation systems. These men lately obtained the titles to their land by brave and unwearying effort in the courts, in conflict with claimants of a Spanish grant. A considerable area of the lands below Yuma is subject to overflow when the river gage at Yuma indicates a height of 24 feet and 6 inches, and provision must be made to protect this land with levees. This overflowed district has an area of approximately 30,000 acres in Arizona and 18,000 in California. A further study of this question is being made. Should it appear feasible to construct such works as would irrigate this area, especially the mesa lands, a thorough system of drainage will be necessary. On August 31, 1903, the President ordered that the Fort Yuma abandoned military reservation, in Arizona, be reserved and set apart for the uses of the Reclamation Service. The order is as follows: It is hereby ordered that the Fort Yuma abandoned military reservation lying south of the Colorado River, in Arizona, with the buildings thereon, excepting the building and lands reserved for the Weather Bureau by Executive order dated March 26, 1902; the building and lands reserved for the customs service by Executive order dated April 29, 1902, and the rights of way of the Yuma Pumping Irrigation Company, conferred by the act of Congress approved January 20, 1893, and all legal vested rights, be, and it is hereby, reserved and set apart for the uses of the Reclamation Service. A table showing the classification of lands about Yuma is given below. In the preparation of these tables and similar ones an arbitrary division into sections was made, and the acreage computed in first, second, and third class. The average elevation of each section was considered in relation to the construction of laterals for irrigating this section and in connection with the effect upon the cross section of the main canal. |