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MIDDLE VALLEY
ENHANCEMENT
(June-September 2006)
Project Design: Buck
Engineering
Primary Contractor: Cook's
Trucking and Excavating
This 5,200-linear
foot reach of the Valley River is the second large section for which
HRWC has undertaken restoration activities. It is located along US
Highway 19/74 just southwest of Marble in Cherokee County, NC. The
drainage area at this location is approximately 90 square miles.
Nearly 450 linear feet of Sam Branch on the project site was also
restored. The Middle Valley Enhancement project site is owned by Valley
River LLC; a permanent conservation easement was donated for a 50-foot riparian buffer along the entire project length.
Conditions of Site Prior to Project
Airport Road
runs along one side the river for about 2,000 linear feet; the other
side was being leased for grazing of livestock. Cattle had unrestricted
access to the river along the majority of the project length prior to
construction. More than 70% of the project reach had sparse or
inadequate riparian vegetation and in the uppermost section, very little
woody vegetation was present in the vicinity of old log cribbing that
had begun to fail. Downstream project sections were moderately
entrenched and the river had little access to its floodplain. Soil was
being lost from the banks of the Valley River at an estimated rate of
814 tons
per year in the project reach. A significant amount of soil was also
being lost from the banks of Sam Branch.
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Before |
After |
11-04-05 |
11-17-06 |
11-04-05 |
11-17-06 |
Instream Technologies Applied
A
conservation easement was obtained from Valley River LLC, the owners of
the entire left bank of the Valley River along the project reach, about 1,500 linear feet of the
right bank, and both sides of Sam Branch; however, two additional
landowners on the right bank did not participate in the project.
Additionally, Airport Road runs along the right bank for about 2,000
linear feet, with less than 50 feet between the road and the river in
most places. For these reasons, the design addressed dimension for
the Valley River primarily by grading the river banks to construct
floodplain benches at the bankfull elevation (based on reference
conditions in a downstream reach) in several locations along the project
length. A few rock vanes and j-hook
vanes were constructed to help redirect flows away from the outside
banks, provide limited bank stabilization, and enhance habitat for
aquatic life. Several of a new type of structure, nicknamed "log jam",
were constructed in a long pool
to provide additional aquatic habitat, the primary target being the sicklefin
redhorse (a recently announced candidate for endangered species listing
which is found in the Valley River). The new channel design for
Sam Branch addressed dimension, pattern, and profile using floodplain
benches and log structures.
Linear Feet of Stream Restoration
5,200
feet
of Valley
River
450 feet of Sam
Branch
Linear Feet of Riparian Buffer to be Restored and/or Protected
5,200 feet
of Valley River (50-foot buffer)
900 feet of
Sam Branch (30-foot buffer)
 Native trees and
shrubs were used to restore the riparian buffer (30-50 feet wide) along
the left bank (descending) of the Valley River and both sides of
Sam Branch.
Fencing and
alternative watering sources were offered to the landowners in
conjunction with the restoration work so that livestock grazing could
continue, but the option was declined. Tree species
planted included Red Maple, River Birch, Sycamore, Green Ash, Tulip Tree, Silky Dogwood, Sweetgum, Elderberry, Alder, and Persimmon.
A native warm-season grass mix was also utilized at the site.
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