|
Hoko
The Hoko River is
the largest watershed within WRIA 19. Excess sedimentation is a major
limiting factor for this watershed, with sources from roads and clearcuts.
The
sedimentation has led to channel instability and a change in substrate to less
suitable
spawning gravels. Sediment transport and water velocity effects are worsened
by a
severe lack of large woody debris (LWD), which is another major limiting factor.
Many
riparian areas are dominated by hardwoods, and will not contribute to future
LWD. Also,
it is believed that the change in age and type of surrounding forests contributes
to an
increased frequency and severity of peak flows. Another major problem includes
encroachments to the floodplain, such as riparian roads and an old railroad grade
in the
mainstem, as well as dikes and channelization in the Little Hoko River. These
floodplain
impacts constrain the channel, reduce side-channel habitat, and reduce riparian
vegetation
and associated LWD recruitment. In addition, riparian roads also contribute to
excessive
sedimentation. Another potentially large problem is low flows in the summer and
early
autumn. Low flows contribute to high water temperatures and limit the spawning
distribution of fall chinook to less stable areas of the mainstem, possibly increasing
the
likelihood of scour during peak flow events. The naturally low flows are worsened
by
water withdrawals.
Minor limiting factors in the Hoko River include numerous culverts and changes
in the
estuarine area. Improving culverts would increase coho and steelhead habitat,
but would
not address the large problems in the mainstem that impact all salmonid species.
The
estuarine habitat has been altered by sediment deposition in recent history.
The effects of
the estuarine sediment deposition on salmon are unclear.
Sekiu
The Sekiu River has extensive sedimentation problems stemming primarily
from high
road densities and mass wasting sites. The sedimentation has led to debris flows
that
have incised the mainstem channel and removed LWD. The mainstem provides critical
rearing habitat as well as spawning habitat for all salmon species in that watershed.
The
floodplain impacts to the mainstem such as the Mainline and other riparian roads
have
greatly impaired salmon production through an increase in channel instability
(constrictions), increased sediment, loss of riparian vegetation, and loss of
off-channel
habitat. Other major problems include a lack of LWD and deep pools, extensive
riparian
areas that are dominated by hardwoods, and management activities that have significantly
reduced the age of the surrounding forests. The alteration of riparian in the
mainstem and
South Fork has resulted in high summer water temperatures, while the forest management
activities have contributed to increases in water turbidity. These water quality
issues are
a major problem for salmon within the watershed. A minor limiting factor is passage
problems, most impacting coho and steelhead.
Pysht
One major limiting factor for the Pysht River is sedimentation from roads
and mass
wasting sites which leads to channel instability, especially in the mainstem.
Another
major problem is the lack of LWD, which results in increased channel instability
and
peak flow impacts as well as decreased the formation of pool habitat and
spawning gravel
storage. The conversion of a conifer riparian to open areas and hardwoods
is also a
significant limiting factor, leading to a lack of future LWD and high water
temperatures.
The Pysht River has severe floodplain impacts particularly from Highway
112, which
contributes to sediment problems, reduces riparian vegetation, and increases
channel
instability. The removal of trees along riparian roads also reduces important
riparian
vegetation for salmon. It is believed that the change in age and type of
surrounding
forests contributes to an increased frequency and severity of peak flows.
Minor factors in the Pysht River include the channelization of the lower
mile and a half
of the mainstem, as well as excessive sediment delivery to the estuary.
Members of the
TAG believed that there may have been a loss of eelgrass habitat in the
estuary, but
historical data are not available to demonstrate this. Another minor habitat
factor is
human-caused blockages.
Clallam
The Clallam River is impacted
by excessive sedimentation combined with a lack of LWD and
an open or hardwood riparian area. The altered riparian has contributed
to high water
temperatures in the summer. Significant floodplain impacts include
gravel bar scalping
and riparian road impacts. There has also been a loss of saltmarsh
habitat in the estuary.
It is believed that the change in age and type of surrounding forests
contributes to an
increased frequency and severity of peak flows. Some members of the
TAG expressed concern about the intermittent blockage near
the mouth caused by gravel, however the
problem and potential solutions are not well-understood and need to
be studied before
restoration activities are planned for this issue. Blockages comprise
a lessor impact on
salmon production in the Clallam River, reducing coho and steelhead habitat.
Deep
Sedimentation is the major limiting factor for Deep Creek. Debris flows
have resulted in
extensive channel incision and instability. Large woody debris is lacking,
and the
conversion of riparian vegetation from old conifers to hardwood or
open areas results in a
future lack of LWD as well as high water temperatures. Channel incision
has contributed
to floodplain impacts such as a lack of off-channel habitat, and this
lack of off-channel
habitat has severely impacted all salmonid species in Deep Creek. The
excessive
sedimentation has also impacted the estuary, where the delta has increased
in recent
years. Another major problem is the conversion of surrounding forest
vegetation to
young conifers. The lack of older trees is thought to increase the
frequency and severity
of peak flow events. Channel incision and the lack of instream LWD
worsens water
velocities. Blockages comprise a lessor impact on salmon production
in Deep Creek, and
these are considered a lower priority restoration activity.
Twin
Not much is known about current habitat conditions in the Twin
Rivers. It is believed
that LWD is lacking in the lower reaches, and there is concern about
sedimentation from
roads. Fish passage is an issue in the East Fork of the East Twin River,
and estuarine
impacts exist near the mouths of both Twin Rivers.
Lyre
The Lyre River has been impacted with fine sediments from Boundary
and Susie Creeks.
The fines have degraded spawning habitat and increased water turbidity.
Other major
factors include an alder-dominated riparian in Nelson Creek, a lack
of LWD in Nelson
Creek, Susie Creek, and the lower mainstem, and a channelization
in the lower mile of
the mainstem. “Stream cleaning” or removal
of LWD contributes to the lack of LWD in
this river. Blockages comprise a lessor impact on salmon production
in the Lyre River.
Salt
The greatest salmon habitat problem in Salt Creek is the lack of
LWD, which has resulted
in a loss of holding pools for salmon. Other issues include an
increased demand for
water, unauthorized water withdrawals, and excess sedimentation.
These problems are
likely the result of land conversion to accommodate development.
Development in the
floodplain has altered the riparian, and efforts to return the
riparian to old conifers should
be encouraged. Another significant impact is the loss of saltmarsh
in the estuary due to
roads. Blockages comprise a lessor impact on salmon production
in Salt Creek, reducing
coho and steelhead habitat. Another minor problem is the floodplain
impact by riparian
roads.
Western Strait Independents
The small salmon-producing streams
in the east end of WRIA 19 include Colville, Field,
Whiskey, Murdock, Jim and Joe Creeks. Major problems in these creeks
include a lack
of LWD and a conversion of the riparian zone to alder or open areas.
Excessive
sedimentation is believed to be a problem in Whiskey, Field, Jim,
and Joe Creeks.
Blockages are known problems in Colville, Field, Jim, and Joe Creeks.
Estuarine
impacts have occurred near Whiskey and Jim Creeks.
For small streams in the west end of WRIA 19, major problems include
a lack of LWD in
Agency and Jansen Creeks, as well as in the Sail River. Another
major problem is the
conversion of riparian in Rasmussen, Bullman, and Jansen Creeks,
and the Sail River. In
Snow, Rasmussen, Bullman, and Jansen Creeks, excessive sedimentation
from roads is
another major habitat impact for salmon production, and in Jansen
Creek, the resulting
turbidity from roads is a significant problem. Blockages are
known problems in Agency
and Village Creek and the Sail River. High water temperatures
have been documented in
Agency and Rasmussen Creeks. In the nearshore environment, sediments
from Highway
112 are impacting eelgrass habitat.
Recommendations
Many of the major limiting factors are
similar throughout the WRIA, and several factors
are often the result of a few causes. Because of this, the
TAG recommends the following
actions for the entire WRIA to help address some of these
widespread, complex factors
that stem from similar causes.
· Enforce current environmental regulations, such as the Hydraulic Code,
Forest
Practices Act, Shoreline regulations, Critical Area Ordinances,
and Growth
Management Act.
· Revise the Growth Management Act to protect salmon habitat.
· Protect the channel migration zone (floodplain) habitat. Floodplain
development
leads to a loss of riparian forest and loss of future LWD.
It also increases
sedimentation, channel instability, and water quality problems.
· Protect conifer riparian areas.
· Convert open and hardwood riparian areas to conifer.
· Increase off-channel habitat.
· Increase instream LWD, preferably with attached rootwads.
· Stop the removal of instream wood.
· Prevent the increase of water withdrawals. These can have a large impact
on salmon
because of the naturally low flow conditions in the summer
and early autumn.
· Set up a State/Tribal/County committee to identify and purchase critical
salmon
habitat for conservation and to address problem areas.
|