Mitigation for the Construction and Operation of Libby Dam

Parmenter Creek
Juvenile salmonid abundance estimates conducted in 2000 represent pre-project
estimates, while the surveys conducted in 2001 and 2003 represent estimates after the
restoration efforts on lower Parmenter Creek were completed. We did not survey Parmenter
Creek in 2002. Rainbow trout were the most abundant fish species observed in Parmenter
Creek during all years of sampling (2000, 2001 and 2003; Figure 30), with estimates of 92
and 79 fish per 1000 feet, respectively (Table A5). Statistical analysis was not performed to
compare abundances before and after the stream channel restoration work due to lack of
replication. However, the overlapping 95% confidence intervals for rainbow trout estimates
between years suggests differences were not likely significant. Brook trout were more
abundant in 2000 than 2001 at this site (Figure 30). We did not observe any juvenile bull
trout at this site in 2000, but did observe bull trout at this location in 2001, with an estimated
abundance of 1 fish per 1000 feet (Table A5).
Number Fish per 1000 Feet
140
120
100
80
60
40
20
0
2000 (Pre) 2001 + 2003 (Post)
Year
Rainbow Trout Brook Trout Bull Trout Cutthroat Trout
Figure 30. Cutthroat trout, bull trout and brook trout densities (fish per 1000 feet) within the
Parmenter Creek monitoring site collected by performing backpack electrofishing. Fish
abundance estimates from 2000 represent pre-project information, and surveys conducted in
2001 represent post-project data. Upper 95% confidence intervals are represented by the
whisker bars. The site was not sampled in 2002.
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