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<br />15. STREAM FLOWS
<br />
<br />':-..310
<br />
<br />It appears that the submitted draft of the Report, in which drought-cycle
<br />(1931-1940) virgin :f'lows and depletions were given for the Upper Basin, is
<br />being revised by the Bureau of Reclamation so as to afford uniform treatment
<br />to both basins in, this regard. That :first treatment of the Upper Basin seems
<br />to have been adopted in virtue of the provision of Par. (d) Art. III of the
<br />Compact, wherein "the States of the Upper Division" are obligated not to
<br />cause the flow of the river at Lee Ferry to be depleted below an aggregate of
<br />75,000,000 acre feet for any period o:f ten consecutive years. The Bureau of
<br />Reclamation presents data concerning depletions in the Upper Basin, including
<br />a part of Arizona, although the depletion limitation, or the delivery obliga-
<br />tion, is imposed, not on the Upper Basin, but on '~he States of the Upper
<br />Division",which are defined by Par. (ei) of Art. II, as "the States of Colorado,
<br />New MeXico, Utah and Wyoming." Certainly the States of the Upper Division
<br />are not accountable :for depletions of the flow at Lee Ferry caused by the
<br />State of Arizona.
<br />
<br />The flows of the Colorado River, and some of its major tributaries,
<br />under "virgin" (and presumably long-time average) conditions, at several key-
<br />stations, are given at page 19 of the Report, as follows:
<br />
<br />STREAM
<br />
<br />GREEN RIVER
<br />COLORADO RIVER
<br />COLORADO RIVER
<br />LITTLE COLORADO R.
<br />VIRGIN RIVER
<br />COLORADO RIVER
<br />GILA RIVER
<br />GlIA RIVER
<br />
<br />FSTJMATED FLOW--VIRGIN CONDITIONS
<br />Average Annual
<br />LOCATION Flow (Acre Feet)
<br />
<br />at mouth
<br />above mouth of Green River
<br />at Lee Ferry
<br />near its mouth
<br />Littlefield
<br />laguna Dam
<br />near Phoenix
<br />Dome (near mouth)
<br />
<br />5,903,000
<br />7,289,000
<br />16,271,000 (a)
<br />338,000
<br />310,000
<br />16,451,000
<br />2,282,000
<br />1,271,000 (b)
<br />
<br />(a)
<br />
<br />Whether at Lee Ferry gaging station, or Lee Ferry as definl,'d in the Com-
<br />pact, 1s not disclosed. The difference, which involves but a small
<br />quantity of water, is this. Lee Ferry gaging station is located above
<br />the mouth of the Paria River, whereas Lee Ferry as defined in the Compact
<br />is, "a point in the main stream of the Colorado River one mile below the
<br />mouth of the Paria River," and hence includes the Paria inflow.-
<br />The decline in average aIUlual virgin flows between Phoenix and the mouth
<br />of the Gila River is attributed to "losses in the lower river area."
<br />
<br />(b)
<br />
<br />Under virgin conditione the River, as described in the Report, "was a
<br />growing stream throughout its course until it reached the Black Canyon section
<br />(site of Boulder ram) below which the stream was depleted, except in times of
<br />great flood, by evaporation losses in the desert region." Here, the word
<br />"depleted" refers to conveyance losees in stream channels due to natural
<br />causes, whereas the definition of stream depletions (page 3) refers exclusively
<br />to losses of water caused by human or man-made operations. As employed in the
<br />Report whsn calculating virgin flows, the word depletion appears to exclude
<br />natural channel losses, at least in the Lower Basin, where such losses are
<br />
<br />(22)
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