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bonnSl 6 WATER SUPPLY FOR THE SAN JUAN-CHAMA PROJECT Both Mr. Hill and the B1Jrea1J indicate there could be depletions in the upper bas.in !%grega.ting 7.5, million ~c~e-feet annuaUy if sufficient storage capaCity is provided (Hill-38 million acre-feet; Bureau--48.5 million acre"feet initially). Mr. Erickson's second study shows the same thing (43 miHion acre-feet). Mr. Reynold's study shows deple- tion of 7.2 million with 43 million acre-feet of effective storage. Mr. Sparks' 1961 study C-l indicates about 6.3 million acre-feet would be available annuaJ,iy for upper basin depletion. I would consider the results of this study C-l conservative from an upper basin viewpoint; while it covers the period 1922-60, the study does not reflect the years of high flow prior to 1931. From my analysis of all the above studies and additional material, I can reasonably conclude that the depletions at Lee Ferry under the Colorado River compact could total 7,5 million acre-feet annually pro- vided the Bureau's ultimate plan for 48,455,000 acre-feet of storage is authorized, constructed, and operated. However, it appears unlikely that additional storage capacity will be authorized in the near future. it is not needed for a long time so far as upper basin development is cou,cerned, and there would be extensive water losses from evapora- tion> Without the authorization and construction of additional storage in the upper basin, I believe it is reasonable to conclude that, under presently expected future flow conditions, depletions at Lee Ferry, due to upper basin uses, should be assumed for planning pur- poses not to exceed abo~t 6.2 million acre-feet annually. In my opinion, one flaw in the Bureau's planning in connection with the New Mexico projects is that it is based 'upon 7.5 million acre-feet depletion at Lee Ferry while overall upper basin planning is based upon 6.2 million acre-feet depletion at Lee Ferry. Should New Mexico uses (including a share of evaporation losses from main stem reservoirs) result in depletion at Lee Ferry amounting to 838,000 acre-feet and the storage capacity necessary to permit a total depletion of 7.5 million acre-feet at Lee Ferry is not provided or future flows do not make this amount available to the upper basin under the Colorado River compact, New Mexico's use of water would exceed ;1', . its entitlement to water under the upper Colorado River Basin compact. If one took the position that uses in New Mexico should not result in depletion at Lee Ferry exceeding 11.25 percent of per- missible upper basin depletion under expected flow conditions without additional storage, then depletion at Lee Ferry from New Mexico uses should not exceed approximately 692,000 acre-feet annually. It is my opinion that under presently existing flow conditions and without the authorization and constructHm of additional storage in the upper basin there is no assurance that New Mexico's entitlement will exceed 692,000 acre-feet, , If it can be shown that the water requirements of the existing and authorized developments in New Mexico, the requirements for the Navajo Indian irrigation project, the San Juan-Chama reclamation project, and that part of the Animas-La Plata project in New Mexico, plus an appropriate share of evaporation losses from main stem reservoirs, can be met without exceeding depletion at Lee Ferry of 692,000 acre-feet, then there is no need to raise, at this time, the que3tion as to whether it would be appropriate for New Mexico uses to result in depletions 'which, in aggregate, exceed New Mexico's entitlement based upon the presently authorized storage and expected future flow conditions. ' ' ,;."'-'.-;, "