Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Coho Salmon: Proposed Action
term flow targets: July through September, pages 67 to 68, NMFS 2002 BO).
Additionally, NMFS concluded that flows in the vicinity of 1000 cfs are not
expected to increase temperatures and would have the benefit of dampening the
magnitude of diurnal fluctuations in temperature (as discussed in next sub-section
– Temperature). At this time, Reclamation proposes no changes to the
recommended long-term minimum flows as outlined in NMFS 2002 BO for the
July through September period.
On page 56 of the 2002 BO, NMFS states “[g]iven that coho [salmon] are
primarily tributary spawners, that main stem spawning and rearing habitat is
likely not limiting at the current population size, and recognizing the importance
of the main stem as a migratory corridor for adult and down-stream migrating
smolts, NMFS thinks that the approach contained in this [2002 BO] sufficiently
addresses the adverse effects of the Klamath Project to SONC coho salmon
[ESU]...”. Further, the 2002 BO states that “[c]oho salmon typically rear in fresh
water for up to 15 months, then migrate to the sea as smolts between March and
June” (p. 12, NMFS 2002 BO). Similar to the conclusion in the NMFS 2002 BO,
Reclamation recognizes the importance of the March through June period in the
coho salmon life cycle within the main stem of the upper Klamath River.
In regards to the time period of March through June, under the Proposed Action,
Reclamation will retain the NMFS 2002 BO’s recommended long-term minimum
flows for a dry year water type for releases from IGD 29 . However, unlike the
NMFS 2002 BO, Reclamation proposes to not go below these minimum monthly
flow levels for all water year types. This would be a deviation from the NMFS
2002 BO, which established minimum flows by year type.
The rationale for these minimums and their impact on ESA-listed coho salmon
will be discussed below. The long-term minimum flows for a dry year type were
established in NMFS 2002 and were based on salmon fry habitat suitability
curves utilizing estimated unimpaired flows (see Section 11.4.2 – Rationale for
long-term flow targets: March through June, pages 63 to 67, NMFS 2002 BO).
In most years, Reclamation anticipates operating above the cumulative monthly
minimum flows. The following exceedence table reflects the estimated frequency
of IGD flows that might be realized under the Proposed Action (Table 3-17).
29
Dry year water type releases: March 1,450 cfs; April 1,500 cfs; May 1,500 cfs; and
June 1,400 cfs.
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