Draft EIS_072312.pdf - Middle Fork American River Project ...

20120723-4002 FERC PDF (Unofficial) 07/23/2012
the Rubicon River upstream of Hell Hole reservoir and downstream of the dam to the
Middle Fork American River (El Dorado National Forest, 1977; Tahoe National Forest,
2003, both as cited in PCWA, 2007b).
During quantitative sampling in 2007 and 2008, a total of 127 hardhead were
captured at the river and reservoir sampling sites. Nearly 90 percent (111) of these
hardhead were small fish less than 6 inches, and more than 95 percent (121) were from
Ralston afterbay (112 from electrofishing, 9 from gill netting). The remainder were
captured in the Middle Fork American River upstream of Ralston afterbay. During
qualitative sampling in 2007, 78 hardhead were captured or observed in the Middle Fork
American and Rubicon Rivers just upstream of Ralston afterbay. Most of these fish were
small; the largest was 5.4 inches.
Moyle (2002) states that hardhead mainly spawn in April and May, but spawning
may extend into August. YOY data collected by PCWA were inconclusive for
determining the hardhead spawning date but PCWA assumed that hardhead spawn from
early April into the summer.
Central Valley Steelhead Distinct Population Segment
The California Central Valley Steelhead Distinct Population Segment is federally
listed as threatened and critical habitat extends downstream from Nimbus dam on the
American River. Naturally spawned steelhead in the lower American River belong to the
Northern Sierra Nevada Diversity Group of the Central Valley Steelhead Distinct
Population Segment, listed as threatened under the ESA in 2006 (71 Federal Register
[FR] 834 [January 5, 2006]). Critical habitat includes the American River downstream
of Nimbus dam (70 FR 52488; September 2, 2005). The American River population is
classified at high risk of extinction; increasing demands for water and the potential
effects of climate change are likely to increase this risk (NMFS, 2009a).
It does not currently occur in project-affected waters. Historically, steelhead and
Chinook salmon are reported to have migrated up the Middle Fork American River past
the mouth of the Rubicon River and in the Rubicon River upstream to the mouth of Pilot
Creek. Extensive stocking of out-of-basin rainbow trout has taken place in the project
area and began as early as the 1800s. At one point, native resident rainbow trout in the
upper Middle Fork American River basin would have been genetically related to the
anadromous steelhead in the basin, but subsequent interbreeding with introduced out-ofbasin
stocks makes it unlikely that a significant genetic legacy remains in resident
populations.
NMFS’ Biological Opinion and Conference Opinion on the Long-Term
Operations of the Central Valley Project and California State Water Project (NMFS,
2009b) contains a Reasonable and Prudent Alternative that includes reintroducing Central
Valley Steelhead into the upper American River watershed. NMFS’ Public Draft
Recovery Plan for the Evolutionarily Significant Units of Sacramento River Winter-run
and Central Valley Spring-run Chinook Salmon and the Distinct Population Segment of
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