CRAA
had the contractor cut the bank back to a 45 degree slope above the low water line
and remove the excess soil, about 60 cubic metres worth. The contractor then placed
12 large tree stumps with 3 m trunks into the bank with the base of the stump facing
into the current. The long tree trunks will hold the stumps in place long into the
future and assist in stabilizing the bank from future erosion. The bank was then covered
with a layer of rock ranging from 12" to 30" to protect the soil from the eroding
force of the water. The combination of the stumps extending into the stream and the
rocks should protect the bank for many years to come. The project design should also
result in the development of a pool along the stabilized bend to provide greater fishing
opportunities.
Section
of river before bank stabilization.
Bank
cut at 45 degree slope.
Addition
of stumps to the base of the bank.
Rock
layer being added to bank.
Same
section of river after bank stabilization.
Close-up
of the completed bank stabilization showing the rock layer & tree stumps.
In
the spring of 2003 CRAA will plant the entire open area along the river with a mixture
of large trees (up to 35 feet tall) and several hundred smaller trees to connect up
the riparian forest that is broken in this section. CRAA will also plant other open
sections in the lower river at the same time to establish a full riparian forest zone.
