Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Endangered Suckers: Review of Proposed Action
Access to Pelican Bay may become limited at low lake elevation. Pelican Bay, an
area of better water quality, has been used by adult suckers during poor water
quality events in UKL (Reiser et al. 2001, Banish et al. 2007). At a lake elevation
of 4138 ft, adult sucker access to Pelican Bay is altered as water depth > 3 ft is
approximately 0.5 miles east of the entrance to Pelican Bay (USFWS 2002). The
influence that better water quality extends away from the refuge area and into the
lake proper is poorly understood (USFWS 2002).
Sucker Entrainment and Passage
Since 2001, Reclamation has installed fish screens at both A-canal and the outlet
of Clear Lake. The fish screen at A-canal was designed to protect most juvenile
and subadult suckers (greater than 30 mm total length) which can pass through the
trash rack openings. Adult suckers are unable to pass through the openings on the
trash rack in front of the A-canal fish screen. The design of the fish screen creates
positive sweeping flows across the screen surface that is believed to provide an
additional benefit by deflecting larval suckers (10-20 mm) which are of a size that
could pass through mesh openings. Similar sweeping velocities at a facility near
Red Bluff, California, reduced fish entrainment by successfully bypassing up to
46% of larval Sacramento suckers (Borthwick and Weber 2001). Similarly,
preliminary tests by Reclamation showed a comparable percentage of larval
suckers and other larval fish were successfully bypassed at the A-Canal screen in
2003 (Bennetts et al. 2004).
Although no fisheries investigations have been conducted to evaluate the fish
screen at Clear Lake, fish salvage operations in the Lost River downstream of
Clear Lake have captured very few suckers since installing the fish screen
(Reclamation, unpublished reports).
Reclamation and other agencies continue to recognize the large number of
unscreened diversions in the Upper Klamath basin. Reclamation is working with
other agencies, including USFWS and ODFW, to identify and screen the
numerous unscreened diversions in UKL. Reclamation and USFWS biologists
believe this action is warranted because screening non-Federal diversions in UKL
will provide the greatest potential benefits to endangered sucker populations
where they are most abundant, populations are relatively robust, and the larger
number of juvenile suckers in UKL is particularly vulnerable to entrainment if
private diversions on UKL remain unscreened. Reclamation initiated a process
for the UKL Fish Screen Program by issuing a grant to ODFW and leveraging
Federal and State funds to provide 90 percent of the cost of constructing fish
screens for willing landowners.
Presently, entrainment of larval, juvenile, and adult suckers at other Project
facilities including Gerber Reservoir, Miller Creek, Tule Lake, and diversions in
the Lost River and Klamath River may occur as a result of the proposed action
(Reclamation 2002). However, Reclamation proposes to work with other
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