7282

• UCREFRP Catalog Number: 7282
• Author: U.S. Fish and Wildlife Service, R. I. P.
• Title: Final Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin.
• USFW Year: 1987.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

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b. In the interim period until consultation is completed, Reclamation has
committed to assist in meeting a 2,000 cfs minimum flow below the
confluence of the Gunnison and Colorado Rivers an average of 9 out of
10 years. Preliminary studies have been done to attempt to assess the
impact of Blue Mesa on the rare fish habitat and to determine Blue
Mesa's ability to offset these impacts and to contribute to the
recovery program. Any preliminary flow regime necessarily will be
' subject to refinement as additional scientific information is
accumulated but provides a basis for determining whether Blue Mesa
could assist in meeting flow needs in the interim period.
c. Reclamation and the Service will cooperate with the Implementation
Committee in establishing an instream flow right, pursuant to State
laws, to guarantee the delivery of any flow releases through fish
' habitat (see Section 4.1.3).
4.2 HABITAT DEVELOPMENT AND MAINTENANCE
Alteration and loss of habitat have contributed to the decline of the four
Colorado River fishes. Recovery of these species may be aided by assessing
the quantity and quality of habitat needed for recovery and by developing or
enhancing habitat through management techniques, such as instream flows,
creation of backwaters, or other nonflow activities, etc. The use of any of
these management techniques will also be considered in relation to the
1 successful implementation of other habitat management techniques to provide a
balanced contribution from each. Initially, the habitat development and
enhancement techniques described in this chapter will be applied
experimentally to determine if the rare fishes will use developed habitat and
' if such techniques contribute to recovery. Appropriate permits and NEPA
compliance will be required.
Habitat management techniques will be tested in a variety of habitat types,
including backwaters, spawning habitat, grow-out (rearing) areas (see
Section 4.3.2), or will be used to open new habitat through the construction
of fish passages and jetties. Testing should address the questions of
' quantity of specific habitats needed and the problems associated with habitat
quality. For instance, if lack of backwater habitat is contributing to the
low numbers of young-of-the-year squawfish, then increasing the quantity of
backwaters may increase the abundance of young squawfish. Likewise, if lack
of habitat quality is the problem, the focus should be on improving, in
selected locations, the quality of existing backwaters and spawning habitat by
improving flows, water temperature, water chemistry and turbidity, decreasing
the numbers of predatory.fish, etc. The role of changing flows in creating
important ephemeral backwater habitat must also be determined.
4.2.1 Backwaters
Young-of-the-year Colorado squawfish are most often found in backwaters, since
backwaters provide nursery and feeding habitat. Backwaters can be created by
manipulating river flow to retain the characteristics typical of the river
system. Regulation structures such as Flaming Gorge can be operated to
' control river flow and temperature to maximize the quantity and quality of
backwaters in certain river reaches during periods when they are most critical

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