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AUGUSTINE HEIGHTS
CHANNEL IMPROVEMENTS
| PROJECT TYPE: |
Bio-Stabilization |
| CLIENT: |
City of Eureka |
| APPROX VALUE: |
$400,00 |
| DURATION: |
September 2005 -
April 2006 |
PROJECT SUMMARY:
Provide channel improvements to an unnamed tributary along
2,250 lineal feet of creek bank which included slope
protection, grade control, and storm water outlets at
designated points along the channel. Planting and seeding
of a variety of Missouri-native species was required to further
restore the area in addition to maintenance of the vicinity to
ensure establishment of the planted areas.
PROJECT SOLUTION:
Three methods of reinforcement were used to create the
reinforced channel on this project. The first was 700
feet of Ajax Bank Protection. Essentially these large
concrete blocks look like Legos which interlock together to
form protective rows along the channel.
The second method was to protect the slope with Geo Web, a
plastic material with a honeycomb structure that is filled with
dirt and plants (see photo and illustration below). The
plants take root and eventually grow into their own, natural
form of reinforcement. This type is not good for use
along toe areas because of scouring during times of extreme
flow.
That led to the third method, gabion baskets which were added
to prevent scouring. Gabion baskets are large PVC
covered, galvanized steel baskets filled with rock (see photo 5
below).
Along the channel 30 large trees had to be removed but by the
end of the project Ideal replaced them with 61 canopy trees.
Additionally 5,300 small plugs and Missouri-native bare root
plants filled the Geo Web cells. Some of the plants
included a variety of sedges, rushes, zigzag and giant
goldenrod, ferns, river bulrush and so on. Of the 400
live stakes used tree varieties included river birch, alder,
green ash, sandbar and black willows, silky dogwoods, and
buttonbush.
All projects of this type require permits from the Department
of Natural Resources before construction may proceed.
SPECIAL CONSIDERATIONS:
This project was made extremely difficult by six feet of mud in
the creek bed which literally swallowed equipment and made
access through the channel very complicated. Countless
hours of remediation were necessary in order to get equipment
into place and a by-pass pump was set up to drain water from
areas where work was underway.
The first two months went very smoothly but rains slowed what
should have been the final two weeks of the project into two
additional months.
PHOTOS:
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Remediation underway
to make the creek passable for heavy equipment.
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A shot of the muddy
conditions at the jobsite.
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Initial work begins
in order to stabilize the creek and get the project
underway with A-Jacks and coir logs lining the channel.
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The creek conditions
before work began.
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Gabion baskets are
placed along the bottom of the creek to prevent scouring.
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A glimpse of the
progress several weeks into the project.
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Filter fabric against
the bank prevents infiltration of the soil.
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Heavy equipment in
the creek bed alongside the gabion baskets.
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Photo of a Geoweb wall. The purpose is to plant the
pockets in the face to allow vegetation to grow. |
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