WSP11051

• File Number: 8281.300
• Description: Colorado River Studies and Investigations - Colorado River Consumptive Uses and Losses Report
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1980
• Title: Report of the 1975-79 Annual Consumptive Uses and Losses in the Arizona Portion of the Upper Colorado River Basin
• Water Supply Pro - Doc Type: Report/Study

o

Records of water usage at the Navajo Powerplant were supplied by the

('.)

~ Navajo Project Generating Station. The water year values are shown in
to
1\) Table 1. This water is pumped from Lake Powell and is entirely consumed.
o

Conclusions

The estimated consumptive uses and losses in the Arizona portion of

the Upper Colorado River Basin for the 1975 to 1979 water years are shown

in Table 1. The values shown for Page, Wahweap, and Navajo Powerplant

represent water pumped from Lake Powell (or from shoreline wells) and

clearly represent a depletion to the Colorado River at the Compact Point.

The remaining consumptive uses and losses are "on-site" and do not

necessarily represent a corresponding depletion to the Colorado River.

The drainage system of the study area is characterized by sandy washes

which only intermittently contain a flowing stream. No doubt if the

"on-site" depletion water had been allowed to flow downstream, some of it

would have been lost through channel evaporation and phreatophyte growth.

It is at present impossible to estimate with any assurance what propor-

tion of this water would have been naturally lost before reaching the

Colorado River at the Compact Point.