WSP07539

• File Number: 8281.300
• Description: Colorado River Studies and Investigations - Colorado River Consumptive Uses and Losses Report
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 10/1/1991
• Title: Consumptive Uses and Losses in the Arizona Portion of the Upper Colorado River Basin for the Water Year 1990
• Water Supply Pro - Doc Type: Report/Study

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Consumptive Uses and Losses

17

Table 6.-Stock pond and reservoir evaporation, 1990
Lake
Surface Surface Elevation evaporation Precipitation Net evaporation
acres full acres used (feet) (inches) (inches) (inches) (acre-feet)
RESERVOIRS
Irrigation
Many Farms 1,800 450 5250 56 10.46 45.54 1,710
Marsh Pass 40 10 6200 40 11.66 28.34 20
Walker Creek 30 8 4900 59 5.67 53.33 40
Others 38 9 55 4.47 50.53 40
Recreation and
irrigation
Pinnacle 15 8 7400 35 12.21 22.79 20
Round Rock 83 40 5500 57 11.42 45.5S 150
Tsaile 260 130 7010 35 12.21 22.79 250
Wheatlields ...11! -lli. 7290 32 12.21 19.79 -1!Q.
Total 2,53S 7S5 2,440
STOCK PONDS
Cococino County SO 15 5500 57 5.70 51.30 60
Navl\io County 40 7 5800 55 9.27 45.73 30
Apache Connty ~ ~ 5900 53 9.45 43.55 ~
Total 766 130 480
Grand Total 3,304 915 2,920

CONCLUSIONS

This report assesses the total consumptive use of the Arizona portion of the
surface water systems, depletion of ground water, and evaporative losses.
Clearly, the amounts of water used by the NGS, city of Page, and Wahweap
and Lees Ferry recreation areas are direct depletions of water from the Upper
Colorado River System, but the situation is not as clear for other consumptive
uses and losses occurring in other sections of the study area, For example, the.
source of water used by the Navlljo Nation for domestic and municipal purposes
is fr!lm wells, some exceeding 1,000 feet in depth. For our purposes here, it is
considered to be consumed and is a depletion to the Colorado River Basin, But
this may not actually result in a reduction of Colorado River streamflows in the
same year that the withdrawal occurs, Little knowledge and information exists
of ground-water movement and subsurface flow rates in the study area that are
accurate descriptions of the effects on riverflows.