WSP02299

• File Number: 8240.300.03
• Description: San Juan River - Recovery Implementation Program - General Info
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 3/7/1996
• Author: Fish and Wildlife Se
• Title: Biological Opinion
• Water Supply Pro - Doc Type: Biological Opinion

Mr. Calvin Joyner

4

C) factors, have resulted in such drastic reductions in the populations of
C) Colorado squawfish and razorback sucker throughout their ranges that the
~ Service has listed these species as endangered and has implemented programs to
~~ prevent them from becoming extinct.
~

~ The biological opinion issued by Region 6 of the Service on October 25, 1991,
for the Animas-La Plata Project found that the proposed development and
subsequent depletion of 57,100 acre-feet of the San Juan River's flow would
jeopardize the continued existence of the endangered Colorado squawfish and
the threatened razorback sucker, The razorback sucker was listed as
endangered on October 23, 1991 (56 F.R. 54957), The Bureau worked with the
Service through the informal consultation process and stated in the July 30,
1991, memorandum that it would release flows from Navajo Dam to mimic the
natural hydrograph and further help recover the endangered fishes. Another
element of the reasonable and prudent alternatives provided in the opinion
called for the formulation of a binding agreement, a Memorandum of
Understanding, to protect the releases to be made from the Navajo Reservoir to
and through the endangered fish habitat of the San Juan River to Lake Powell.
The Memorandum of Understanding also states that future Federal actions
resulting in minor depletions could occur up to a cumulative maximum depletion
of 3,000 acre-feet per year. However, each of these minor depletions would be
subject to section 7 consultation, On February 26, 1996, the Service issued
another biological opinion to the Bureau on the Animas-La Plata Project. The
binding agreements executed in support of the 1991 biological opinion continue
with all force and effect.

The potential effects of the pre-1983, post-1982, and proposed water
depletions by the San Juan National Forest have been analyzed in the context
of the ongoing Navajo Dam consultation and those commitments and agreements
derived from the Animas-La Plata consultation. Of primary concern is the
quantity of water provided to and through the habitat of the endangered
Colorado squawfish and razorback sucker in the San Juan River. The amount of
water depleted from the river's flow (283.57 acre-feet) by the post-1982 and
proposed depletion projects is considered part of the 3,000 acre-foot
cumulative annual depletion and should be reflected in water accounting for
the San Juan River. The anticipated depletion of 57,100 acre-feet for the
Animas-La Plata Project will not occur for an estimated 7 to 10 years. It is,
therefore, not considered likely that the loss of 283.57 acre-feet of the
river's flow would jeopardize the continued existence of the species under
consideration. However, the pre-1983 loss of 34,656.32 acre-feet is ~
considered a large loss of water that may have contributed to the decline of
the endangered fishes and is, therefore, likely to jeopardize the continued
existence of the endangered fishes.

Critical habitat has been designated for the Colorado squawfish and razorback
sucker within the 100-year floodplain in portions of their historic range
(59 F.R. 13374). Destruction or adverse modification of critical habitat is
defined in 50 CFR 402.02 as a direct or indirect alteration that appreciably
diminishes the value of critical habitat for both the survival and recovery of
listed species, In considering the biological basis for designating critical
habitat, the Service focused on the primary physical and biological elements
that are essential to the conservation of the species without consideration of