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

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

o
( ~~>)
(..:J
(.to,)
l\)
04

Consumptive Uses and Losses

I)

Glen Canyon National Recreation Area

Arizona Colorado River water is used by the Glen Canyon National Recreation
Area (GCNRA) at Wahweap and Lees Ferry. The recreational area at
Wahweap gets its water supply from a series of wells on the shore of Lake
Powell, and the quantity pumped makes up slightly more than 1 percent of the
total consumptive use for the study area. Pumping records for both Wahweap
and Lees Ferry show 450 (:dO) acre-feet of water was withdrawn during water
year 1990. The uncertainty is estimated at 3 percent. This water was used for
domestic purposes at the campgrounds, picnic areas, and trailer park. It was
also used to irrigate approximately 60 acres of Bermuda grass and cottonwood
trees. The domestic waste water is treated and allowed to evaporate from two
lined evaporation ponds with a total surface area of 16.7 acres.

Based on estimates of evaporation and consumptive use by the plants, there is
some water which is unaccounted for and is assumed to be leakage from the
delivery system, the evaporation pond, or deep percolation from irrigation
application. However, since these water losses are difficult to quantify and
verify, the losses were charged as consumptive uses. Therefore, net
consumptive use of water is estimated to be equal to the quantity of water
pumped.

Canyon de Chelly National Monument

The water supply for the visitors' center, employee housing, campground, and
picnic area at Canyon de Chelly National Monument is obtained by pumping
water from wells. The pumps were out of service from October 1989 to
Febl"Uary 1990. The well data submitted for water year 1990 was
20 (:t10) acre-feet. The uncertainty is estimated at 30 percent. Past reports
indicate closer to 30 acre-feet per year consumptive use at Canyon de Chelly
National Monument. The water is used for domestic purposes and for
irrigation of about 2 acres of grass and trees. The domestic waste water is
piped into the Chinle sewage system operated by the Navajo Tribal Utility
Authority and evaporated in a series of lined evaporation ponds.

Navajo Indian Reservation

Community Water Systems.-Statistics from the Division of Community
Development of the Navajo Nation reveal that various community water
systems served about 66 percent, or 20,800 of the 31,429 people residing within
the study area on the reservation in 1980. This percentage was used for 1990
resulting in 25,600 out of 38,880 people being served. These systems include
those operated by the Navajo Tribal Utility Authority (NTUA), the Bureau of.