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Michele Whitt Smith, Robe Valley Flood Control District Commissioner, walks near a rock vane water control structure. This structure and others, were part of the NRCS’ emergency watershed protection project. |
It started as a natural disaster: Heavy rainfall resulting in
massive flooding – lifting homes off of their foundations – sending them
floating down the South Fork of the Stillaguamish River.
It ended with a successful project that united a community.
After the 2003 flooding of the Stillaguamish River, citizens of Robe Valley were
devastated, frightened and in need of help. They turned to Snohomish County. The
County, in turn, requested assistance from the Natural Resources Conservation
Service (NRCS), the USDA agency that administers the Emergency Watershed
Protection Program (EWP).
"The objective of the program is to assist entities in implementing emergency
measures to relieve imminent threat to life and property created by a natural
disaster," says Ron Shavlik, NRCS Assistant State Conservationist.
According to Shavlik, public and private landowners are eligible for assistance,
but both must be represented by a project sponsor. "A project sponsor must be a
public agency of state, county, city government, tribal government, or a special
district. Snohomish County is the sponsor helping facilitate the EWP process,"
he says.
With assistance from the County, Robe Valley landowners organized the Robe
Valley Flood Control District. They did so to coordinate and facilitate the
community’s needs. "The Flood Control District was born out of this issue –
three homes were lost to the flooding in November 2003," says Michele Whitt
Smith, Flood Control District Commissioner. "The need was to save the rest of
the community from going downstream," she says.
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During construction of the rock vane water control structures, placement of the large rootwads will create habitat for aquatic wildlife. (Photo taken by Rick Bolger.) |
"The Flood Control District provided all land rights to do the
repair work as well as securing the necessary permits," says Ms. Whitt Smith.
"Many agencies came together to make this project a success."
The EWP project began with an engineering design for protecting the stream banks
from raging waters.
"The Robe Valley EWP project has five rock vanes which jet out from the bank to
the center of the river," says Dean Renner, NRCS Stream Mechanics Engineer. "It
is designed to withstand the effects of a 100-year flood and force the river
current away from a dangerous bend in the river aimed at residents of Robe
Valley," he says.
According to Renner, river currents tend to cut out the bottom of a bank on an
outside bend in a river. "More erosive power comes from the bottom of the stream
channel. By deflecting this force away from the bank into the center of a
channel we protect the bank," he says.
"You can see how the design changes the flow of the river – gently pushing water
to the main channel," says Ms. Whitt Smith. "The vanes are doing exactly what
they have been designed to do," she says.
The design is also more fish-friendly then simple rock barriers, which biologist
say makes for poor habitat.
"The vanes are designed to collect sediment and logs to resemble a natural
bank," says NRCS’ Renner.
According to Mr. Renner, the project is designed to keep the main force of the
river in the channel with slow moving water at the bank’s surface. The project
will prevent stream bank erosion, not flooding. "Floods are supposed to go over
the top of the bank. Vegetation will protect the top of the banks from eroding
away," he says.
"You can see how the engineering and design are working to keep the river from
eating away at the river’s bank," says Ms. Whitt Smith. "The design is
incredible."
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Dean Renner, NRCS Stream Mechanics Engineer, examines the rock vane structures designed to prevent further erosion of the river bank by diverting the water current. |
After winter snowpack conditions, spring runoff flowed down the
South Fork Stillaguamish River without any problems. "We have had some high
water events this season, but nothing of as great magnitude as before," says Ms.
Whitt Smith. "So far, so good."
The EWP project transformed the steep cliffs of the banks into a gradual decline
to the river’s edge. Plants were reestablished along the stream banks protecting
soil from further erosion.
Raging flood waters altered the stream banks but could not alter the community’s
resolve. "This project is going to make it easier for people down the line to
come together and solve local concerns," Ms. Whitt Smith says.
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