Watershed Management Plan - Mason County

Appendix
A Sub-basin Summaries
HABITAT
The Skokomish sub-basin provides habitat for many anadromous fish
species including chum, chinook, coho, steelhead, and cutthroat and trout.
Bull trout, resident cutthroat trout, and rainbow trout are also present.
Historically, sockeye stocks were also present. Individual sockeye are
observed every year in the lower Skokomish basin, but biologists don’t
believe a viable population is currently present. A landlocked (Kokanee)
sockeye population exists in Lake Cushman and Lake Kokanee and is
supported by hatchery augmentation. Landlocked chinook salmon are also
present in Lake Cushman. Following is a discussion of fish habitat in the
North, South, and Main forks of the Skokomish River.
• The North Fork of the Skokomish River provides habitat for
resident and anadromous fish. Assessment of habitat quality is
limited due to litigation surrounding the Cushman Dam. Several
culverts block resident fish migration on Dow Creek, Big Creek, and
near the Tacoma Utility Power House. An earthen dam on the
Enetai Creek also blocks fish passage (WCC, 2003). In addition,
McTaggert Creek has two partial fish barriers and an impassable
structure that diverts the entire flow into the hydropower facility
(Skokomish Tribe, personal communication, December 23, 2004).
• Habitat quality in the upper and middle reaches of the South Fork
of the Skokomish River is good. The U.S. Forest Service is restoring
riparian corridors near Lebar Creek and Cedar Creek, as well as other
riparian zones under their ownership. Erosion at the abandoned
hydropower development, near Lebar Creek and Brown Creek, is a
potential problem (WCC, 2003).
Habitat quality in the lower reaches of the South Fork is
compromised by sediment aggradation, channelization, and loss of
riparian vegetation. The source of built-up sediment is likely the
result of mass wasting and road failures related to forestry practices
upstream, including in Vance Creek. The lower reaches of the South
Fork flowing through the Skokomish Valley have been channelized,
armored, and diked and riparian vegetation throughout the valley is
sparse due to agricultural land-use. Woody debris is often removed
for private use including firewood and fence posts (WCC, 2003).
• Barriers, channelization, sediment build-up (aggradation), and
riparian loss reduce habitat quality along the Main Stem of the
Skokomish River. A majority of the main stem has been diked and
channelized which has eliminated access to side channel and wetland
habitat and reduced channel complexity. Over half (62%) of the
mainstem is sparsely vegetated and has been cleared for agriculture
(WCC, 2003). One factor that may contribute to an elevated degree
of sediment aggradation in the main stem is the diversion of stream
flow from the North Fork to Cushman Dam. With less water
flowing in the Skokomish River, the river may not be able to carry as
page 84 Final Plan for County Adoption – May 11, 2006