WSP07757

• File Number: 8220.100.40
• Description: CRSP
• Basin: Colorado Mainstem
• Date: 1/16/1958
• Author: USDOI
• Title: First Annual Report on the Statuts of the Colorado River Storage Project
• Water Supply Pro - Doc Type: Annual Report

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6 REP()~ ON OOWRADO RWER STORAGE PRO\rEOT
,
Res~rvoir ope~ations will necessarily depend upon the conditions
of use; of flow, jtndof storage as they develop. If, in the course of
actual operatioqs during the period 1958-70,. there are appreciable
deviations from; average flows the foregoing premises, including the
criteria for ope~ation of Glen Canyon. and Hoover, should be. re-
considered.! . .
Application a':'d further discussion of; and the resulting computa-
tions under the Joregoing basic premises are contained hereinafter. .

j ASSUMED STREAMFLOW CONDITIONS

. AnassumptiO\1 as to expected streamflows is necessary in any
reservoir-~I!ing Slemonstration. The ass~mption of averag~ stream-
flow conditIons Isa reasonable one for this study. ReserVOir opera-
tion studies pr4sented herein assume average streamflow 'at Glen
Canyon equal t$ that obtained from the period 1914-45, inclusive,
modified to reflqct present conditions of development and progres-
sively reduced e1\ch year through the operation period consistent witb
a projected .SCh~.' dule of increasing annual depletions. .Of course,
streamflow reali ed at Glen Canyon will depart from the average
in any given ye '., but speculation involving variant& in the develop-
ing physical sltu~tion is premature and would not be useful. . .
Lake Mead stprage reached a low point immediately prior .to the
1957 flood seasolildue to a recent drought (1953-56 bemg the lowest
4 years in seque1\cein the history of the Colorado River). The flood
runoff in 1957 was considerably greater than average and Lake Mead
activestorage cohtent is expected to be 20.0 million acre-feet on April
1, 1958. Therefore the operation studies be~in April 1, 1958, with
Lake Mead activie storage content of 20,0 milhon acre-feet.
Historically the annual flow at the Glen Canyon Dam site aver-
aged. 1.3.8 miliio* acre-feet during the 32-year. period 1914. to. 1..945,
inclusive. Whe1 modified to reflect present conditions of develop-
ment in the upper basin, the average annual flow is about 13.1 million
acre-feet. Furt~er developments in .tbe upper basill, such as con.
struction of wa~er-consuming projects and storage reservoirs, will
require further adjustment in .the expectec!f1ow. Table I is atabulll-
tion of the flows' to be expected. in the.,near future at Glen Canyon
Dam. assuming lliverage streamflow conditions.

TABLE I

[MnItonacre.feetJ

,

,.
i
Year beg~InF Apr. 1-

Adjustment for new
upstream uses

Assumed
fuflowto
Glen Cnnyon
-Reservoir

Averagefiow
at Glen
Oanyon Dam
. \vitli prosent Oonsumptive Upstream
> development use fncludJng storage ll'alns
evaporation

1958'.*__h.n_~_~~~__"h.L__________U"__~_~_h
1959_.__._-_~~_n_____.n__~_".~.._______~_._"_.
ID60n___.______.__~_.._~_~"__________"n__n___
1961.:_______.h_____"____"l.._._.._.____"___"_.~.
1962___._.__u_.u.____"__~._._._._."..n__n___
1963....~n__._____.......~__"___"___._..."_..__

. !1I1~.~~ ~~~~ ~~j~.~~~ :~~~-~!:~~ :~:~ -:~ ~~~.~~~~~:_j

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