9316

• UCREFRP Catalog Number: 9316
• Author: Camp Dresser & McKee Inc.
• Title: Replacement of the Plateau Creek Pipeline.
• USFW Year: 1996.
• USFW - Doc Type: Denver.
• Copyright Material: NO

The Recovery Program for Endangered Fish Species in the Upper Colorado River
Basin (Recovery Program; USFWS 1987) has sponsored evaluations of tributary
streams, both from a biological (e.g., Price, upper Colorado, and Upper Green Rivers
habitat assessment or restoration projects) and hydrological perspective (e.g., in stream
flow studies in the upper Colorado, Duchesne, Little Snake, and White Rivers) (1994 -
1997 work plans). Thus, there is a considerable amount of information about tributary
streams that would be useful in evaluating their role in recovery of the listed fishes in
the upper basin. However, the relative importance of the various tributaries has not
been evaluated with standardized criteria. Amore comprehensive, comparative
assessment of the potential contributions of tributaries has been needed to clarify
valuable hydrologic, water quality, and ecological linkages within the basin; identify
potential limiting factors influenced by tributaries; and clarify the role of tributaries in
maintenance of the native fish community that supports populations of the fisted
species. Knowledge of the ac#ua1 or potential recovery benefits within and downstream
of each tributary can provide the basis for predicting how management actions may
optimize the recovery benefits that tributaries may offer. However, the potential
benefits of a tributary may not be fully realized at this time, because of the existence of
one or more obstacles to the recovery effort. There remain some cases in which
access to habitat potentially valuable to adult or juveniles is totally blocked by barriers
(e.g., the upper Colorado River, the upper White River), or influenced by water quality
or other unknown factors (e.g., Dolores River). In other cases, the presence of a
formidable population of nonnative predators may not allow establishment of
endangered fish populations (e.g., Marsh and Brooks 1989). Finally, recovery potential
of large areas of habitat where the mainstream river has been converted to a reservoir,
but where large areas of tributary streams remain has not been fully evaluated (e.g.,
Lake Powell and associated tributaries: Dirty Devil, Escalante, and lower San Juan
Rivers). The potential benefit to the endangered fishes by future recovery actions in
tributary streams remains to be evaluated.
This study is viewed as a first step in evaluating the significance of tributary streams in
the UCR basin by providing a systematic review. The following goats guided this study:
1. To determine the direct. contribution of each tributary for supporting the life
history needs of the endangered fishes;
2. To evaluate the potential of tributary streams to support expanded or
additional populations of the listed fishes;
3. To determine indirect abiotic contributions of tributary streams, such as water,
sediment, and other factors judged to be important for recovery downstream in
the basin;
4. To identify obstacles that prevent a stream from reaching its potential in terms
of support for populations of listed fishes; and
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