WSPC01194

• File Number: 8240.300.31.A
• Description: Colorado River Threatened-Endangered Species - Recovery Program - San Juan - Project Description
• State: CO
• Basin: San Juan/Dolores
• Water Division: 5
• Date: 2/1/1995
• Author: Unknown
• Title: San Juan River Basin - Recovery Implementation Program - Program Document - February 1995
• Water Supply Pro - Doc Type: Report/Study

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3.3 PROTECTION, MANAGEMENT, AND AUGMENTATION OP HABITAT

3.3.1 Statement of Problem

Modification and loss of habitat have contributed to the decline
of the Colorado squawfish and razorback sucker in the San Juan
River. For example, young-of-year Colorado squawfish are most
often found in low-velocity nursery and feeding habitats such as
backwaters and side channels. Paucity of such habitats or water
quality may be limiting recruitment. These habitats can be
created and seasonally maintained by manipulating river flow.

Regulation structures such as Navajo Dam can be operated to
control river flow and temperature to maximize the quantity and
quality of habitats in certain river reaches during periods when
they are most critical to the endangered fish species. These
habitats can also be developed by connecting existing side
channels, gravel pits or ponds to the river through the provision
of beneficial flows or channel modification. The trade-offs of
providing this habitat through flow manipulation or channel
modification will be examined in light of the dual goals of this
Implementation Program, with emphasis on providing the habitat in
the most effective manner.

Recovery of these species may be aided by protecting or enhancing
habitat through management techniques, such as habitat flow
management, protection of habitats and flow, or other measures.
First, however, the quantity and quality of available habitats
must be assessed, and based upon this information, decisions can
be made as to how to best achieve the desired results.

Federal, state, local, and tribal agencies will work
cooperatively and expeditiously to quantify, protect, manage and,
where appropriate, augment flows and habitats of the San Juan
River. The water needed to provide flows for the recovery of
endangered fish species (habitat flows) will be protected under
this Implementation Program in a manner consistent with all state
and tribal laws.

3.3.2 Course of Action

3.3..2.1 Research

Important reaches of the San Juan River for different life stages
of the endangered fishes will be identified. Those reaches will
be monitored during releases of test flows from Navajo Dam to
determine habitat quality and characteristics over an array of
flow regimes and to identify and quantify the response of the
endangered fish species to specific flows at these locations. In
addition, responses of other native and non-native fish species
will be characterized. The research necessary for this effort is