7754

• UCREFRP Catalog Number: 7754
• Author: Harris, R., H. Sersland and F. P. Sharpe.
• Title: Realities of Providing Water for Endangered Fishes in the Upper Colorado River System.
• USFW Year: 1981.
• USFW - Doc Type: \
• Copyright Material: NO

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Flows in the major tributaries such as the San Juan, Green River, Yampa, and

Gunnison Rivers have likewise been erratic with some drying completely up at

some points during extreme drought periods. Sediment loads in the r~ver have

also varied naturally from less than 1 percent in the Colorado at Lee Ferry to

over 10 percent in lower reaches of the San Juan, Dirty Devil, Escalante, and

Paria Rivers.

With construction of the Colorado River Storage Project and other multipurpose

developments in the Upper Basin, about 25 percent of the natural flow ~s presently

being used. The natural and present day distribution above Lee Ferry ~s shown ~q

Tab Ie 1.

River basin
Upper Green River
Yampa River
Duchesne River
White River
Total Green River
(above Green River,

Table 1*
Estimated flow of Colorado River
above Lee Ferry by river basin
(Percentage distribution)--
Na tur a 1
flow
13 .1
8,1
5.2
3.8

Remaining
flow /".
10.2
8.0
3.0
3.8

Utah)

36,2

23.6
15.5
5.4

30.9

10.8
15.5
5.4

Upper Colorado River
Gunnison River
Dolores River
Total Colorado River
(above Cisco, Utah)

Upper San Juan
Total San Juan River
(above Bluff, Utah)

Total Colorado River
(Lee Ferry, Arizona)

4).1
8.0

32.3
7.1

14.4

11.8

100.0

75.0

Because there are numerous small tributar es that help make up the total

Colorado River streamflow, the p~centage of large tributaries do not sum