WSP11823

• File Number: 8281.400
• Description: Colorado River Studies and Investigations -- Colorado River Depletion Projections
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 3/25/1955
• Title: Report on Depletion of Surface Water Supplied of Colorado West of Continental Divide
• Water Supply Pro - Doc Type: Report/Study

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DEPLETION OF SURFACE WATER SUPPLIES

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The i population of the east bay cities is approximately that for
which provision should be made on the western slope and the popula-
t.ion of, t.he Los Angeles area is very much great.er. It. is reasonable
t.o assume, therefore, that while diversion requirements for indust.rial
and municipal purposes on t.he west.ern slope of Colorado may be quite
large, t.he act.ual consumption of water resulting in depletion of stream-
flows sh.ould not exceed 1 acre-foot per year for each 10 persons.
In other words, allowance for the consumption of 100,000 acre-feet
per yeat in addition to the actual consumption of water in the mining
and processing of oil shale should be ample to cover all other industries
and the,uses of the population supported by all industries.
It is t<hus unlikely that stream depletions resulting from full indus-
trialization will amount to more than 200,000 acre-feet per year; allow-
ance for depletions aggregating 300,000 acre-feet per year would cer-
tainly provide ample margin for any conceivable development stem-
ming fro.m processing of the shale oil reserves, and be enough to cover
any probable use of the coal deposits.

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NEED FOR STORAGE OF FLOOD WATERS

Undllrpresent condit.ions, very lit.t.le water would be available during
the irrigation season to satisfy the diversion requirement.s of industry.
The nat.ural flow of the rivers is already being used to its utmost to
serve lands under irrigation, except during the winter months when
t.he demand for water is insignificant and except during the period of
snow melt when the rivers are in flood. Hence, conservation of flood
flows by storage in reservoirs will be necessary to satisfy even a small
industrial' demand.
The only existing reservoir which might be used for this purpose is
Green Mountain Reservoir on Blue River constructed by the United
States as part of the Colorado-Big Thompson project. The diversion
requirements of the oil shale industry itself might be satisfied by re-
leases from this reservoir but the far greater requirements of the other
industries' could not be so met. The additional storage reservoirs
which will: be needed do not have to be located upstream from Rifle;
on the cOI~trary, there would be considerable advantage in having a
large reservoir in the immediate vicinity of the potential industrial
area.
: Opportunity exists for the creation of a suitable reservoir by con-
structionof a dam in De Beque Canyon at the lower end of the valley
within which the industrial development would presumably be cen-
tered. Diyersion requirements of such industries could be satisfied
by the withdrawal of water from the reservoir without regard to the
inflow at the time. Return waters, except the very small proportion
which might be unduly contaminated by chemical processes,could be
returned to the same reservoir without waste downstream. All
irrigation requirements in the Grand Junction area could be satisfied,
without corltlict with any other use, by the release of water from the
reservoir, and the average quality of the irrigation water would be
somewhat improved over that )Jow available in the summer months.
lt is recognized that the cost of construction of such a storage
project would be large, primarily because of the necessity of relocating
the trunk h~ghway and railroad which now follow Colorado River.
This!cost, however, would be insignificant in comparison to the

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