9305

• UCREFRP Catalog Number: 9305
• Author: U.S. Fish and Wildlife Service.
• Title: Final Biological Opinion for the Operation of Flaming Gorge Dam.
• USFW Year: 1992.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

I
Figure 2, taken from Tyus and Karp (July 1991), shows the conceptual
relationships between a natural hydrograph and the timing of life history
requirements for the Colorado squawfish, humpback chub, and razorback sucker.
It is this natural hydrograph with a large spring peak; a gradual descending
limb into early summer; and low, stable flows through the summer, fall, and
winter that the Service believes creates the bes`t'habitat conditions for rare
and endangered fish in the Green River Basin. This flow pattern maintains
long-term stability and geomorphology of the channel, prepares spawning areas,
and forms nursery habitats.
DEVELOPMENT AND EXTENT OF PERTINENT SCIENTIFIC DATA BASE
The Act of 1973 (P.L. 93-205) charged all Federal Agencies to consider the
needs of species listed as threatened and endangered. The Act also mandated
all Federal Agencies to consult with the Service to ensure that their actions
were not likely to jeopardize listed species. Early consultations revealed
the need for scientific information on the endangered species. In 1979, the
collection of life history data to expand the scant data base that existed for
the rare and endangered fish of the Upper Colorado River Basin began with
formation of the Colorado River Fisheries Project. In 1982 Reclamation and
the Service continued studies on endangered fish under the Colorado River
Fishery Monitoring Program. These studies were to examine the effects of
flows from Flaming Gorge Dam primarily on Colorado squawfish. In 1985 the
Service and Reclamation agreed to an interagency Flaming Gorge Studies program
that began in 1986 and ended in 1990. That program evaluated habitat
requirements and streamflow needs of the rare fish and provided flow
recommendations in a final report dated July 1991 (Tyus and Karp 1991).
Just prior to implementing the Recovery Program in 1988, a multiagency Flaming
Gorge Section 7 Consultation Team was formed to evaluate biological
information and ongoing studies prior to issuance of the biological opinion.
The final products formulated under the direction of this team were the
consolidated hydrology and biology reports. The Final Consolidated Hydrology
Re ort (Smith and Green 1991) provided hydrologic information on the past and
current operation of Flaming Gorge Oam and discussed models which could be
used to predict changes in sediment transport, temperature, and channel
morphology resulting from recommended operational changes included in this
opinion. The final consolidated biological report titled Habitat Use and
streamflow Needs of Rare and Endangered Fishes in the Green River Utah (Tyus
and Karp 1991) merged the results of numerous studies done by a variety of
government and private researchers. Together, these consolidated reports form
the basis for the Serviceys recommended refinement of the existing. operation
of Flaming Gorge Dam to improve downstream conditions for rare and endangered
fish in the Green River.