|
|
Driving east on Highway 36 Fox Creek is located
between Cummings Creek and MS Weares monitoring sites. Fox Creek
is a tributary of main stem Van Duzen River, and merges with the
river just upstream from the junction of Cummings Creek. The Fox
Creek monitoring site is tucked well into the redwood forest,
and several miles from Highway 36 and in the town of Carlotta.
The site is situated 40° 31.170' North and 124° 00.018'
West, and its catchment area encompasses approximately 2.09 miles
of stream network. The site is located in the redwoods with a
sizable buffer zone of hardwoods like Red Alder within the riparian
zone around the stream. Elevations in Fox Creek range from 151
feet at its mouth to over 1,360 feet in the upper reaches, and
the monitoring site is approximately 118 feet in elevation. The
watershed is completely in private ownership with virtually all
timber holdings and timber harvests conducted by Humboldt Redwood
Company (formerly PALCO). Vegetation is predominantly mixed and
evergreen (Redwood) forest throughout. The catchment area of a
monitoring site is important when considering upslope factors
that affect water quality in the stream. This area represents
the true watershed that lies above the point where water from
the stream is sampled, and from which all rainfall and sediment
are channeled into the stream down to the point where water is
withdrawn for turbidity and suspended sediment analysis.
Stream discharge is directly proportional to the
size of the catchment area - the greater the area, the more water
is carried by the stream during storm events. Fox Creek is relatively
small compared to other streams within the project area, and the
stream drains an area of approximately 2.49 square kilometers
which is equivalent to 0.96 square miles. During the first year
of sampling (HY07) volunteers recorded a maximum discharge of
105 cubic feet per second (CFS) and an average discharge of 13
CFS, a maximum turbidity of 1,596 Nephlometric Units (NTU) and
an average turbidity of 173 NTU. In HY08, there was a maximum
discharge of 113 CFS and an average discharge of 19 CFS, a maximum
turbidity of 2,972 NTU and an average turbidity of 219 NTU over
the winter sampling season. Over the two seasons combined (HY07-HY08),
the maximum discharge was in HY08 at 113 CFS with an average of
19 CFS, maximum turbidity was also in HY08 at 2,972 NTU with an
average of 196 NTU. This translates to an average of 1,597 tons
of suspended sediment per square mile per year.
Fox Creek used to be a perennial stream but now
does not fully run year round and is therefore referred to as
an ephemeral stream (as opposed to a perennial, year round stream).
As the stream runs considerably dry in the summer, temperatures
during this time of the year were not measured. Fox Creek has
a road density of about 9.3 miles of roads per square mile of
watershed. As with all of the catchment areas within the lower
basin, this density of road networks receives a rating of extremely
high. In the 17-year period from 1991 through 2007, the proportion
of the area harvested for timber equaled 71.8%, with clear cutting
accounting for 28.9% of the total area.
|
