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<br />COLORApO RIVER STORAGE PROJECT
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<br />reflect experienced and anticipated man-made depletions, Were used
<br />in estimating the future], water supply available at Glen Oanyon,
<br />We believe that it is pertinent to point out that the historical flows
<br />of the Oolorado River at Glen Oanyon have been very erratic, rang-
<br />ing from a low of 3.9 minion acre-feet in 1934 eo a high of 21.2 million
<br />acre-feet in ] 9] 7, EveJl the year-to-year flows have varied greatly.
<br />For example, the 1956 flow was 8,6 million acre-feet whereas the 1957
<br />flow was ]9.] million acre-feet. Because of the erratic flows, any
<br />estimate of future water availability is subject to greater deVIation
<br />from actual flows than would be the case if historical flows were more
<br />uniform, Thus the pedod required to fill the Glen Oanyon reservoir
<br />to a reasonable operating level and the amount of water available for
<br />power and other purposes could vary substantially from the estimates
<br />used in the Bureau's analysis, For example, should "ctual flows 'fol-
<br />low the historical pattern for the 32-year period ]926 through 1957
<br />rather than the 32-year period 1914 through 1945 used by the Bureau,
<br />the aVerage annual flows would be less than the flows used in the
<br />Bureau's analysis by about 1.7 million acre-feet or about 12 percent.
<br />Should the actual flows follow the historical pattern for the 44-year
<br />period 1914 through 195;7, the average annual flows would be less thaI).
<br />the historical flows used! by the Bureau by about 0,6 million acre-feet
<br />or about 4 percent,
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<br />Water releases required to meet lower baSin commitments
<br />An important factor 'in estimating power production of the Glen
<br />Oanyon unit is the determination of water releases required to meet
<br />lower basin commitments, Water release requirements to the lower
<br />basin are covered princi'pally in the Oolorad, 0 River Oompact of 1922,
<br />and the Mexican Treaty of 1945, Oertain questions concerning re-
<br />quirements for water releases to the lower basin under these agree-
<br />ments are before the SU;preme Oourt of the United States in the case
<br />of Arizona vs, Oalifornia, et a!.
<br />In the analysis, the Bureau assumed that minimum annual water
<br />releases to the lower basin would be 8,35 million acre-feet at Glen
<br />Oanyon, Also, in the analysis, the Bureau states that utilization Of
<br />any of the assumption~ underlying the basic water supply studies'
<br />does not carry with it ~ny actual or implied finding of legal restric-
<br />tions or limitations, '
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<br />Marketior power,produced
<br />The Federal Power Glommission issued a report, dated June 1958,
<br />on the potential mark'ets for power expected to be developed. at,
<br />presently authorized hydroelectric plants m the Oolorado River basin,
<br />The FPC concluded th~t, in view of the large amounts of additional
<br />energy it estimates wil~ be needed, power from presently authorized
<br />projects will find a ready market in the area, provided its cost is
<br />competitive with that I>f equivalent power from fuel-electric plants,
<br />Wit!J. respect to the c,?ll).petitiveness of costs, the ,Burea!,'s repaym~nt
<br />sect10n of the analys1s ,1S based on average sellmg prlCes of 6 mills
<br />a kwh for firm energy at>.d 2,5 mills a kwh for nonfirm' energy, These
<br />prices a~e lower than ~he Bureau's estim~te of the average ?ost of
<br />alternatiVe steam-electr:lC energy produced m large, modern, priVately
<br />owned plants, The Bureau's estimate of the cost of alternative
<br />steam-electric energy delivered to representative load centers in the
<br />market area is 7,27 mi)ls a kwh for firm energy and 2.73 mills akwh
<br />for nonflrm el).ergy.
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