WSP03306

• File Number: 8281.300
• Description: Colorado River Studies and Investigations - Colorado River Consumptive Uses and Losses Report
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1984
• Title: Colorado River System Consumptive Uses and Losses Report 1976 - 1980
• Water Supply Pro - Doc Type: Report/Study

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States or i~ satisfaction of the
Mexican Treaty: obligation." Nearly all
'the water e,,;ported from the Upper
Colorado River system is measured;
however, the remaining beneficial
consumptive use, for the most part,
must be estimated using theoretical
methods and techniques. In the Lower
Colorado River system tributaries to
the mainstream, similar methods must be
employed to determine the amount of
water consumptively used.
Reservoir evaporation loss is a
consumptive use associated with the
beneficial use of water for other
purposes. For the purpose of this
report, main stem reservoir evaporation
is carried as a separate item for the
Upper and Lower Basins.
Channel losses within the system
are normally construed to be the

consumptive use by riparian vegetation
along the stream channel (or conveyance
route) and the evaporation from the
stream's water surface and wetted
materials. Seepage from the stream
normally appears, again downstream or
reaches a ground water aquifer Where it
may be usable agaia. A decided lack of
data and acceptable methodology along
with the intermittent flow characteris-
tics of many Southwest streams combine
to make ,a reasonable determination of
channel loss difficult. Channel losses
have not been estimated for this report
within the Upper Basin nor on the
tributaries of the Lower Colorado River
mainstream. Chaanel losses on the
mainstream below Lee Ferry have been
estimated pri!llarily by the inflow-
outflow method.

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