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Sierra Pacific Power Company made emergency repairs to protect facilities on the River, such as the hydroelectric plants, and is now rehabilitating theses areas using bioengineering techniques for soil and bank stabilization.
Bioengineering techniques are environmental-friendly methods that prevent erosion and stabilize slopes. Plants, or a mixture of plants and engineering structures, are used. The techniques are cost-effective, attractive, and good for the environment. Vegetated slopes cool the river, prevent sediment runoff, act as a filter for pollutants and provide habitat for aquatic and other wildlife.
Sierra Pacific helped the river after the flood by installing vegetation and slope stabilization techniques to the riverbank at it's hydroelectric plants. Below are some examples of how Sierra is continuing to help it's community.
Farad Hydroelectric Plant
Sierra installed riparian vegetation along the top of the rip-rapped
portion of the riverbank using brushlayering techniques. Willow,
dogwood, aspen and woods rose were planted in this area. Baskets
made of fine-mesh coir matting were filled with soil and woods rose.
These baskets, along with cottonwood stakes, were planted among the
rocks on the side slope.
Treatment
Brush bundles, consisting of willow and woods rose, were placed in a trench
dug at the top of the river bank. Baskets, formed from matting and soil,
were potted with woods rose. The baskets were planted among the rock riprap
that was installed following the January 1997 flood for bank stability.
Willow, cottonwood, dogwood, and alder stakes were also planted among the rocks.
Fleish Hydroelectric Plant
Slope stabilization will be achieved using vegetated geogrids. This
consists of live cut branches interspersed between layers of soil
wrapped in coir matting. (Coir matting is made of coconut shell.)
Brush is imbedded between successive wrapped 'lifts' or layers of fill at the outside edge. Each layer of brush or live branches is covered with soil and lightly compacted. The geogrids provide additional reinforcement at the outset. Once the live cuttings become established, their root systems become entangled with the grids and bind the entire system together in a unitary, coherent mass. The entire area will be hydromulched with a riparian seed mixture that will include a tackifier to help hold in moisture.
Treatment
Slope was cut back where possible to a more gradual angle. Matting was
used to line the bank and secure the soil. Willow and cottonwood stakes
were used to secure the matting. Rooted woods rose, sage and rabbit
brush were planted along the slope and at the toe and shoulder of the slope.
Verdi Hydroelectric Plant
The treatment in this area is similar to the Fleish Plant, except the
matting will consist of wetland sod that will be used in a lift application.
This will provide the desired slope stability. Steep areas above river
flow will be terraced and matted. Wetland vegetation sprigs will be
interspersed among the lifts.
Treatment
A roadway, cut by the Army Corps of Engineers during their emergency dredging
project, was gradually sloped and laid with a wetland vegetation sod.
Steep slopes, caused from the flood were filled in, matted and planted
in a manner similar to the Fleish treatment. Final hydromulch was
applied on areas impacted during construction.
