Some
people think that Chimacum Creek's headwaters
are in the Olympic Mountains, but in actuality
they are within the hills around Beaver Valley
(East
Fork Chimacum Creek) and West Valley near Eaglemount
Road--Peterson and Delanty Lakes. It is all
local rain fall and other precipitation that
feeds the creek system, running directly into
the creeks in the wet months or slowly filtering
through the soil, which feeds Chimacum Creek
year round even in the dry months.
In the 1800's Chimacum
Creek (48° 00.706
N, 122° 46.488 W) was
a healthy, vibrant, meandering creek (figure
1). Chimacum Creek had all the levels
of a forest, canopy, understory, shrub layer,
and litter layer. The water had a complexity
of woody debris, there were many nurse logs
nearby, the air was cool and the water had
high levels of oxygen.
When the dairy farmers
moved into the Chimacum Valley they needed
a more efficient way to access the creek
water.
What they did was straighten Chimacum Creek
(figure 2), they
channelized the stream. By straightening
the creek and
removing the
forests, the water
moved too fast for young fry to survive.
The temperature also increased thereby
decreasing the amount of dissolved oxygen.
By the 1960's
90% of the salmon population was gone.
The chum salmon
population was wiped out by the 1980's.
So in the 1990's it was decided that something
needed to be done to restore the salmon
to our watershed.
What the North
Olympic Salmon Coalition (NOSC) is
currently doing is trying to get Chimacum
Creek back
to its pristine state so that the chum
salmon that was reintroduced will survive
and thrive. By the 2000's salmon are
in the creek again but there is still
more work to do. Efforts include planting
trees to regain the tree cover (which
entails
getting
rid of the
canary grass that infiltrated the area),
and to re-meander the creek. Students
here at Chimacum
Middle School are helping test
the water quality and monitor the creek
as
it passes
through our school to ensure that the
water is healthy enough to support
the chum salmon
on its own (not needing to hatch them
at a hatchery).
Figure
1. A meandering stream or creek. (This
is not a picture of Chimacum Creek,
merely a representation of any creek.)
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Figure
2. Straightened creek. (This
is not a picture of Chimacum Creek,
merely a representation of any creek.)
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Here are some notes
that Audrey Miles A. Cherney, a NOSC Restoration
Steward, sent me from what she taught our 6th
graders:
Chimacum
Creek
Chimacum Creek is home to at
least three types of fish who belong to the
salmon family (called salmonids). Summer chum
(also called dog salmon), coho (also knows
as silver salmon), and cutthroat trout are
the three confirmed salmonid species in Chimacum
Creek. The original salmon habitat was spruce-cedar
bog conditions with beaver ponds, vast forests,
wetlands, and side channels, but 90% of that
is now gone. In the valley, the forest was
cleared and the creek was ditched and straightened
to drain the land and increase the available
area and productivity for agriculture.
Straightening a stream channel and removing large woody debris, such as fallen
trees, large limbs, and root wads, reduces the amount of space for the fish
to live (habitat), and the habitat that remains is of lesser quality. Large
woody debris (LWD) increases channel complexity, habitat diversity, and provides
better place for all kinds of fish, including salmon, to grow and thrive. Riparian
vegetation keeps the stream water shaded and cooler, a necessary condition
for salmonids, and it keeps many weeds out of the stream channel. Shaded gravel
riffles and pools make betters sites for fish to make their nests (called a
redd, pronounced like the color “red”) where they lay their eggs
to grow and hatch. Pools and back eddies created around LWD are necessary features
for young fish to escape the faster stream currents, so that they can rest
when they get tired. Streams that do not have weeds in the channel and have
more trees to shade the water have lower water temperatures and typically more
dissolved oxygen, which are essential for salmon to thrive. In addition to
providing shade, woody plants (shrubs and trees) stabilize banks and help slow
the release of water into a stream—which help prevent destructive floods
and prevent the bank from washing away (erosion), as well as acting as a filter
to keep pollutants from tainting the water, which can kill vulnerable eggs
and young fish. Leafy debris from trees and shrubs are also an important food
source for the macroinvertebrates (insect-like organisms) that salmon eat.
In the mid-1980’s, the Irondale Road culvert in Chimacum Creek washed
out of place during a big storm, which happened at a critical egg-laying (spawing)
time for the summer chum salmon, which were in serious decline already. The
road fill and sediment buried their spawning grounds and effectively wiped
out the last of the local population. In the mid-1990’s, Wild Olympic
Salmon and NOSC began a brood stock program which released a new generation
of summer chum, effectively reinstating the summer chum population. Today,
NOSC and its partners are continuing their efforts to save, protect, and restore
native salmon populations and their habitat in Chimacum Creek and many, many
other streams within the North Olympic Peninsula in Washington State.
Thank you Chimacum School, and Mr. Gonzalez’ 6th grade science classes
for your efforts and support to understand Chimacum Creek’s conditions!
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