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

page 166

166 PROBLEMS OF IMPERIAL, VALLEY AND VICINITY. Water supply and irrigation requirements. [Acre-feet.] Month. Discharge of Animas River. Demand for- Prior rights.' La Plata Mesas project. Balance for Overland project. Demand of Overland project. Demand on storage April....... fiay....... June....... July....... August..... September. Total 32, OW 116,000 167,000 55,000 36,000 46,000 2,000 4,flOQ 6,000 4,000 3,000 1,000 10,000 12,000 12,000 10,000 4,000 4,000 20,000 100,000 149,000 41,000 29,000 41,000 20,000 50,000 75,000 50,000 37,000 17,000 9,000 8,000 452,000 20,000 52,000 380,000 249,000 17,000 i Diversions partially above gaging station with only consumptive use as a loss for the stream flow. From the above table the necessity of storage is comparatively small, and although shortages would Ve somewhat heavier in occasional years of low run-off, the provision of storage does not appear essential. Storage, if desired, can be provided to a necessary degree with small inland reservoirs within the project or by the construction of Animas reservoir just above Durango. Conclusion.-All data on the physical details of this project are preliminary-to the extreme, but from a review of available data the unit cost of construction will apparently be high. The project has but one diversion site, and the construction of a small main canal with a view of enlargement as settlement progresses does not appear feasible. The large initial investment required, together with a nigh unit cost per acre, will probably deter construction for a considerable time. Suggestions have been made that this project be extended much farther west, and this seems physically possible. The ultimate acreage would then be governed by available water supply in the Animas River. Stdrage may be developed at the Animas reservoir just abpve Durango in sufficient quantity practically to control the river. With occasional rather severe shortages, the diversions could be based on the average available flow, of which 639,000 acre-feet would be available for this project. With the longer canals required for such a large project, diversions of 3£ acre-feet per acre may be expected, limiting the ultimate project to 183,000 acres. As an alternative to the above scheme, diversion might be made from the Animas River at the Animas reservoir, the area so covered being in general the' same as for the Overland and La Plata Mesas projects combined. Greater latitude of canal locations would, be present with possibly lower total cost for the project. TURLEY PROJECT. Irrigable area roughly estimated at 400,000 acres. Mean annual temperature, 50°. Mean annual precipitation, 6 to 8 inches. Elevation, 5,000 to 5,700 feet. Interval between killing.frosts (summer), 140 days.