WSP07709

• File Number: 8281.300
• Description: Colorado River Studies and Investigations -- Colorado River Consumptive Uses and Losses Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1977
• Title: Colorado River System Consumptive Uses and Losses Report -- 1971-1975
• Water Supply Pro - Doc Type: Report/Study

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New Me~ico. Utah. Arizona).
The oytflow point and drainage area for each
is shown, in table C-1. The boundaries of the
reporting areas are shown on the frontispiece
map.
The lalgest consumptive use of water in
the U ppar Colorado River Basin results from
the irrigation of about 1.5 million acres of
pasture a:nd harvested cropland. In the Upper
Basin, th~re is little opportunity for measuring
irrigation ,consumptive use directly by inflow-
outflow m~thods. Therefore it was nec-
essary to determine this use empirically.
.
Specifical,ly. irrigation consumptive use rates
were com~uted from recorded climate data
for each 01 the reporting years and applied
against the best estimates of irrigation
acreage. The modified Blaney-Criddle
consumpti~e use quotation was selected for
use in the !Jpper Basin.
Irrigated:acreage is the most important
variable in 'the determination of irrigation

consumptive use. Therefore, mcs: ,f the data
collection effort of this study was c",,'ted to
determining this item.
It was also necessary to compte r'i'servoir
evaporation losses empirically. t. ~,.eloping
equations of net evaporation rat=s '." e.lch of
the reporting years and applying l~=;" rates
against the best estimates of reserdr surface
area. For the Upper Basin portion cf this
study. evaporation losses are reported under
the item of use most closely aS5;Jcia,ed with
the principal reservoir function.
Export of water out of the ColoradJ River
system accounts for nearly one-quarter of the
total uses and losses in the Upper Basin. For
the purpose of this report. water excorted
across the basin divide was treated as an
immediate loss to the river system. The
values reported for the Upper Basin are
composed of flows recorded at the diversion
faci I ities and evaporation from reservoirs
associated with export.

TABLE C-f-Colorado River Syslem Consumplive Uses and losses, P.l. 90-537
Drainage Areas by States (and Mexico) and Major Tributary Streams
Units= 1,000 Square Miles
MajorTrjbutaryStre~fltrMl .- ,...,
ThlirSelectedOutflo}'tPointl Wyomilll Colorado "Ia. Hew Mexico AriZDnJ Hevada California
Green River at Colorado River
Confluenc~. Utah !7.1 10.6 17.0 44.8
Upper Main Stam at Green
River Conflllence. Utah 22.2 4.0 26.2
San Juan.ColorJdo at Lee
Ferry, Arizol'" 5.8 16.2 9.7 6.9 38.6
Uttle ColoradO ~iver 5.3 21.2 26.5
near Camerpn. Arizona
Virgin River at LIttle- 5.1
fieid, Arizorta 3.0 1.9 0.2
Muddy River near 6.8
Glendale, N~vada 6.8
Bill Williams Riv~r below
Alamo Oarn,!Arizona 4.7 4.7
Gila River below fainted .
Rock Dam, Arizona 5.6 44.2 (1.1) 49.8
Mainstream and ~emaining Areas
in Lower ~a~in 0.6 28.3 6.9 3.6 (0.1) 39.4
Colorado River Sy~tem
at Southeriy International 241.9
80undary i 17.1 38.6 40.9 20.6 107.2 13.9 3.6 (1.2)
Colorado River Sy$tem 109.6
above Lee FeirY 17.1 38.6 37.3 9.7 6.9
Colorado River Sysiem
beiow Lee Ferty 3.6 10.9 100.3 13.9 3.6 (1.2) 132.3
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