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

11

area and how much water they require.7 It was assumed that the additional
400 acre-feet can be attributed to evaporation losses from the stock ponds.
The number of animals for each agency is shown in table 3. For this report,
1,500 acre-feet was used as livestock total annual water consumption. The
uncertainty in this number was estimated as 30 percent of the total or
:1:450 acre-feet. Livestock consumptive use represents approximately 4 percent
of the total consumptive use of water in the study area.

Table 3.-Number of livestock
Agency Number of Animals
Cows Horses Sheep Goats
Western Navajo Dist. #1 4,930 1,065 13,055 9,460
Western Navajo Dist. #2 2,590 860 9,400 9,505
Western Navajo Dist. #8 6,350 1,130 18,210 16,100
Shiprock Dist. #9 4,450 1,090 9,500 11,580
Chinle Dist. #10 4,650 1,340 10,880 7,730
Chinle Dist. #11 2,245 390 4,100 5.135
Total 25,215 5,875 65,145 59,510

IRRIGATION USES

Within the Arizona portion of the Upper Colorado River Basin, approximately
23 active irrigated areas are scattered across the reservation plus a small
amount of land near Lees Ferry irrigated by the National Park Service. The
limited data available indicates the consumptive use of water for irrigation
comprises only 10 percent of the total use in the study area for 1990. An
accurate assessment of consumptive use on the irrigated land is difficult due to
the poor quality of information, such as the exact number of acres under
irrigation, the cropping pattern for each irrigated area, site climatological
conditions, and the amounts of water actually diverted. In many cases, during
the later part of the irrigation season, farmers have to rely on dry land farming
since there is little water available in the streams. This means that the crops
do not receive their full water requirement.

7 The number of livestock in the area was obtained from "Navajo Nation FAX 88,"
September 1988. Livestock water requirements were provided by Richard W. Rice, Ph.D.,
Extension Livestock Specialist. It is assumed that the numbers of livestock vary insignificantly
from year to year.