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, .~' '.' :' "'<'<. ANNUAL SHORTAGES C.o , ;~.' Shortages Shortages t"tj'i In 1000 In Percent C'J In 1000 In PerC6IJt 1.....:. Year A~re-F6et Of Ideal Sup. Year Acre-Feet Of Ideal Sup. C.:> 1903 38.9 l5.7 1934 115.9 46.7 1904 11l1..9 46.3 1936 2J.4 9.4 1910 19.4 7.8 1939 57.2 23.1 1913 58.2 23.5 1940 81.6 32.9 1924 1.3 0.5 1941 3.8 10'5 1925 11.8 4.8 1943 37.2 15.0 ",-. 1928 12.0 4.8 1944 5.8 2.3 1931 82.8 33.4 Average ~ b;Ti The above shortarAS for the years 1903 and 1904 will be the same for any reservoir operation study, as the project was on river-run in accordance with Rio Grande Compact obligations. By increasing the storage capacity from 60,000 acre-feet to. 100,000 acre-feet the reduction in the shortage of the mean annual water supply would be 3.8 percent or 9,400 acre-feet annually. The mean annual supply that can be provided by reservoirs of various capacities is presented on Plate C. Required Irrigation Capacity The selection of the 60,000 acre-foot Plat ora Reservoir as the optimum irrigation storage capacity required for present conditions was based upun a combination of economic and water supply 8tudies. flate D was developed to show the gross value of crops, 1939-1744 price base, raisAd in the proj- ect under various conditions and with varying a80unts of thA ideal water supply. The upper curve represents the maximum gross crop incCille VQth vari- ous shortages assuming maxL~'1IT, faro effiCiency. It could only be obtained if the entire area were farmed as a unit. J:nder an expert ~gricultural advianx~ The middle curve represent.s the anticipated average gross crop value, 1939- 1944 price base. from the project with average farm effiCiency. It was usec in the 0eterminations to select the recommended capacity. The lower curve shows the gross crop value, 1939-l944 prices, ba~ed upon present crops with maximum f~rm efficiency. All three "s" curves were defined hy computed points which show the crop values for various shortages in water supply. In computing the points the knovm wat.er supply, as shm'm from monU.ly operation stUdies, Was distrj_- buted to the ';rops 2.S the f.'lrmers would do in actual practice and the crop value determined from the reduced crop yield and restricted distribution of crops res.dting from the inadequate suppl:r. The middle curve W.lS used to compete the g:-ocs crop value to be expected for the period of operation studies for reservoirs of various capacities. i'he estimated gross crop values were reduced by present gross crop values to procure the increa3e in crop value assi~lable to the cifferent reser\"oir capacities. '.' Curves were developed, Plate E, which de[ict the best capacity for the project, or, more accurately, the best capacity for the irrigators. The 26