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Kootenai to stay high through mid-month,
work begins on levy
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July 6,2012 |
In response to a direct assistance request from
Boundary County, the U.S. Army Corps of
Engineers is collaborating with county and state
officials to construct temporary repairs and
stabilize a levee protecting critical
infrastructure near Copeland.
Emergency repairs commenced this morning on the
damaged levee, located upstream of Copeland
Crossing on the river's east side. The levee
keeps the Copeland Bridge approach from being
inundated with up to eight feet of water and
also protects area businesses, homes and
agriculture.
Working shoulder-to-shoulder with local and
state representatives, the Corps is stabilizing
the structure by placing riprap armor material
along 500 feet of the levee's riverward face.
Construction is expected to be completed
tomorrow evening using Corps-provided materials
and equipment provided by Boundary County and
the State of Idaho.
Record June rainfall, in excess of 400 percent
of normal in some areas, combined with snowmelt
to elevate the Kootenai River above flood stage
at Bonners Ferry, and cause local flood impacts
downstream of Libby Dam in western Montana,
Idaho and British Columbia.
River elevation at Bonners Ferry peaked
Wednesday morning at 1,766.6 feet, 2.6 feet
above flood stage, before starting to slowly
recede. Current elevation is 1,766.0 feet, but
the river could remain above its 1,764 feet
flood stage level until mid-July.
Further downstream, Kootenay Lake in British
Columbia peaked Tuesday night at 1,753.8 feet
elevation, its highest level since 1974, before
dropping slightly to 1,753.6 feet today.
With such wide spread flooding throughout the
basin, coordinated and cooperative flood
response by the Corps with local, state and
Canadian officials has been prevalent.
Twice during this flood event the Corps and its
Canadian counterpart, BC Hydro, agreed to exceed
normal maximum elevation of 2,459 feet behind
Libby Dam, temporarily increasing the storage
level to 2,460 and later up to 2,461 feet in an
effort to reduce downstream flooding. Because
the Columbia River Treaty also has requirements
for the dam's operation, the Corps and BC Hydro
coordinated these actions with their respective
entities under the Treaty.
Koocanusa Reservoir elevation peaked last night
at 2,459.88 feet. Current inflow is
approximately 47,000 cubic feet per second and
outflow is 48,000 cfs, including 22,000 cfs of
spill.
Even as water levels begin slowly receding
throughout the Kootenai River Basin, the Corps'
Emergency Operations Center continues to monitor
conditions and coordinate flood response with
local county and state representatives.
Meanwhile, Corps' flood team volunteers are
tirelessly inspecting more than 100 miles of
levees and providing technical assistance to
affected communities.
Previously, the team assisted the City of
Bonners Ferry with emergency measures to
stabilize a section of the left bank levee that
had been eroded by high flows. They provided 300
"super sack" sandbags, each with a capacity
equal to about 75 standard sandbags, which were
deployed along 500 feet of riverbank to protect
the Kootenai River Inn Casino and Spa. The Corps
has distributed more than 2,500 sandbags and 700
"super sacks" during this flood event.
The Corps continues to operate Libby Dam to
reduce downstream flood impacts, modifying
outflows to manage reservoir water levels while
simultaneously reducing elevation at Bonners
Ferry.
"As inflows continue to drop, we may begin
decreasing Libby Dam outflow as soon as today or
tomorrow," said Kevin Shaffer, a Seattle
District Army Corps water manager. "This could
be a slow process, as we are seeing very warm
weather forecast for this weekend which will
increase snowmelt and might delay the recession.
River levels have been dropping at Bonners Ferry
since Wednesday, and will continue to decrease
slowly as we reduce outflow from the dam." |
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