WAC Bennett and Peace Canyon Dam Safety Projects

BC HYDRO
W.A.C. BENNETT AND PEACE CANYON
DAM SAFETY PROJECTS UPDATE
November 2013
The W.A.C. Bennett Dam and Gordon M. Shrum (GMS) Generating Station were built in the 1960s and are cornerstones of BC Hydro’s
system. The facilities are located on the Peace River, about 20 kilometres west of Hudson’s Hope. The Peace Canyon Dam was
completed in 1980 and is located downstream of the Bennett Dam on the edge of Hudson’s Hope. As part of BC Hydro’s plan to ensure
safe, reliable power, a number of engineering assessments and projects are underway, or planned to start soon, at the Bennett and
Peace Canyon dams.
W.A.C. Bennett Embankment Dam
Several project activities are underway all aimed at improving monitoring of the dam performance. The project also verifies the
effectiveness of the dam’s filter system and evaluates the stability of the dam.
W.A.C. Bennett Dam Core Instrument Upgrade
A new capital project will be initiated this year to address the open casings left in the core of the dam that were installed during
the sink hole repairs in the late 1990s. The project will implement upgrades to the casings, as required, and potentially install new
instruments for better monitoring of the dam core performance.
W.A.C. Bennett Spillway Chute Upgrade (Phase 2)
The Bennett Dam spillway chute requires upgrades and repairs,
based on findings of field investigations completed in 2011 and 2012.
The scope of the project is to resurface a length of approximately 45
metres across the full width (30 metres) of the lower portion of the
chute, upstream of the flip bucket. Repairs will be similar to the work
completed in the vicinity of the spillway gate structure in 2012 and
will involve concrete removal, installation of new rebar, dowels, new
waterstops at construction joints and concrete placement. Planning
for construction is underway. Construction activities are expected to
start in April 2014, subject to an acceptable reservoir level forecast
for summer 2014. It is expected that two construction seasons (April
to October) will be required to complete the work. A comprehensive
Return to Service Plan has been prepared in case spilling is required
during construction.
Extent of
resurfacing
The highlighted area shows the portion of the Bennett Dam
spillway chute that requires upgrades.
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Peace Canyon Spillway Gate
Reliability Project
Similar to the W.A.C. Bennett
Spillway Gate Reliability Project,
upgrading the Peace Canyon
spillway gate system will ensure
that the facility continues to
provide reliable power. The project
is in the definition phase and the
team is currently undertaking
the preliminary design, which is
expected to be completed in March
2014. Construction activities are
expected to start in early 2015.
The spillway gate system at the Peace
Canyon Generating Station consists of six
spillway bays with radial gates.
W.A.C. Bennett Spillway Gate
Reliability Project
Upgrading the spillway gate system will ensure
continued reliable operation. The project is in the
definition phase and the team is currently undertaking
the preliminary design, which is expected to be
completed in January 2014. Construction activities
are expected to start in the first quarter of 2015.
Constructability and safety by design meetings took
place on site in November.
Spillway gate at W.A.C. Bennett Dam opened during spill operation in July 2012.
W.A.C. Bennett Dam Rip-Rap Upgrade
Since the construction of the Bennett Dam more than 40 years ago, there has been steady deterioration of the rip-rap (rock)
protecting the upstream slope of the dam. Upgrading the deteriorated portions of the rip-rap will ensure long-term dam safety
and erosion protection of the upstream dam slope from impact of waves in the reservoir during wind storms. Trial blasting for
rip-rap at the Sand Flat limestone site was successfully completed in the summer. The project is now evaluating results of the
trial blasting to establish this site as a borrow source for rock to be used for the rip-rap upgrade.
This update is provided to keep residents of the Peace region informed about upgrades and refurbishments being made to the
G.M. Shrum Generating Station, W.A.C. Bennett Dam and Peace Canyon Dam.
Please contact BC Hydro Community Relations at 250 561 4858 or [email protected], or BC Hydro Aboriginal Relations
at 604 528 8394 or [email protected] for more information on any of the above projects.
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