AZ vs. CA:24 California Exhibits, Vol. XXIV; Miscellaneous

page 149

PROBLEMS OF IMPERIAL VALLEY AND VICINITY. 149 General data-Irrigation. Present irrigated area. Estimated additional. Total ultimate. Colorado. Utah___ 58,000 214,000 30,000 272,000 30,000 Total. 158,000 '244,000 302,000 »25,000 acres on San Juan slope. s 105,000 acres on San Juan slope. Note.-Of this 105,000 acres is in the San Juan Basin by diversion from the Dolores. FUTURE IRRIGATION DEVELOPMENT. From the conditions in the Dolores watershed heretofore described, the probable future development may be understood. Further development by individual effort will no doubt be small. For development by organized effort, all projects fall into distinct classes. One of these comprises the smaller projects requiring extension of existing canals and in most cases addition of storage which, although not cheap, can be added from time to time as demand for the irrigated land improves. This class includes the Nucla colony, West Paradox project and scattered areas with present irrigated are# of 19,000 acres and additional available area of 28,000 acres. All other projects with 27,000 acres now irrigated and 197,000 additional acres irrigable, fall roughly into a class which does not v permit of development by sections. The reasons for this are various and will be described for each project individually. The net result in etery case is that the margin between the cost of construction and present value of irrigated land is too small to invite immediate construction. The one factor common to all projects is the lack of good transportation facilities which facilities consist at the present time of a narrow-gage line from 10 to 70 miles from the projects. The probability of the early improvement of transportation facilities was one of the factors promoting the construction of all these projects from 1904 to 1912, during which time large sums were spent for construction on all projects except the Dolores. Actual railroad construction would immediately increase the margin between construction cost for irrigation and value of irrigated lands to a point that might mean the completion of many projects. The various projects and theip grouping in line with the classification adopted for projects are as follows: Classification of projects. Project. Afea now irrigated. Additional irrigable areas. ClaasA. Class B. Class C. Class X. San Miguel.......................................... 1,000 60,000 Lilylands. . i ....>....... 1,000 5,000 5,"666" 15,000 .......... .......... Nucla colony... - ___ ..................... Disappointment Valley.............................. 17,000 West Paradox ............ 3,000 11,000 10,000 Scattered........ ......................... 10,000 Dolores... ........... 80,000 25,000 22,000 .......... Montezuma__ .................... 25,000 .......... From return flow l................................... Total......................................... 46,000 15,000 219,000 10,000 1 Based on reuse of 50 per cent of return flow from projects lying within Dolores drainage area. Return flow 0.75 acre-foot per acre, from 117,000 acres in Dolores Basin. Water reused would be 44,000 acre-feet, or sufficient for 22,000 acres at 2 acre-feet per asre diversion duty!- Acreage not dir :ributed to projects.