Awards of Excellence - ACEC|Manitoba

2012 Awards of Excellence
Award of Excellence – Infrastructure/Transportation
Project Name: Lake St. Martin Emergency Flood Relief Channel
Final Design & Construction Management
Firm:
AECOM Canada Ltd.
Client: The Province of Manitoba
The study Options for Emergency
Reduction of Lake Manitoba and
Lake St. Martin Levels was undertaken
by AECOM and KGS Group and
examined a number of potential options
for dealing with the 2011 flooding on Lake
St. Martin and Lake Manitoba. This identified
the Dauphin River as the hydraulic
constriction in the system and recommended
the immediate construction of
an additional emergency channel from
Lake St. Martin to address the hydraulic
flow restrictions in the Dauphin River and
accommodate additional Lake Manitoba
outflows over the winter.
The contract for the detailed design
and construction management of the Lake
St. Martin Emergency Outlet Channel
(LSMEOC) was awarded to AECOM in
August of 2011. Construction Contracts
with three contractors were signed August
15, 2011.
The objective of this project was to
build an emergency outlet channel from
Lake St. Martin to not only provide additional
hydraulic capacity from this lake but
also to allow maximum operation of the
Fairford River Control Structure to allow
a more rapid reduction in Lake Manitoba
flood levels. The utility of this approach
had been demonstrated during flood
modelling conducted during June of 2011
and addressed the concern that actions
taken to lower Lake Manitoba should not
adversely affect Lake St. Martin.
The challenge was to optimise the design
and develop construction plans and a
schedule that would allow the completion
of the channel before freeze-up in early
November. Construction of the channel
in the time frame available required
optimization of the design to provide the
maximum flow rate with the minimum
excavation volume. In addition the design
and staging had to be flexible enough to
be modified to suit the available construction
equipment.
One of the many challenges faced was
that the site for the channel was on the
northeast side of Lake St. Martin. This site
is remote with no road access. This would
have presented less of a problem if construction
could have been delayed until
winter, but the flooding situation on Lake
Manitoba and Lake St. Martin required immediate
action that could not be delayed.
The conditions on the construction
site were also challenging. The ground
page 32 | Manitoba Consulting Engineer
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