WC136 MayJune 2024 - Magazine - Page 23
Calgary’s chaos in June of that year came about as a result of heavy
rainfall on the melting snowpack, causing rapid flooding of the Bow River.
Banff), adding to the appeal of living there from a recreation and
lifestyle standpoint. But also downstream from mountain fed
rivers prone to rapid changes in river flow.
Frank Frigo, Calgary’s manager of environmental management, puts this topographical Yin-Yang into perspective. “We
have a deep interaction with our rivers… (which) come off our
beautiful mountain terrain immediately to the west,” he said.
But that also translates into “a flashy, very rapid, very extreme
response, to the point where we can go from normal conditions
in the summer within a span of hours… to conditions that are
10 to 100 times more severe.”
As documented by the Conference Board of Canada’s post
flood report titled The Road to Recovery, “projects that began in
2013 (in the wake of the storm) mostly focused on short-term
recovery and flood preparedness for 2014.”
Immediate measures included: replacing 100 metres of track
within the span of a week to the south end of the city’s LRT;
rebuilding trails that had been washed out and eroded; and
fast-tracking residential pumping – meeting 95 per cent of
requests within the span of a week.
Initiatives in 2014 shifted focus to longer-term recovery, rebuilding, and resiliency, including the construction of three new
pedestrian bridges crossing the Elbow River, flood gate improvements at the Glenmore Dam, and flood barrier enhancements at
the Centre Street Bridge.
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However, it took four years to produce a comprehensive, longterm action plan to address future flooding concerns. “Because
of the scale (of the flood), we knew that the interventions would
involve a suite of local and regional structural and non-structural
components,” Frigo added.
Solutions that encompassed “everything from flood insurance
to new reservoirs, local drainage system improvements to lot level
floodproofing programs,” he says, adding that “with all of that
complexity, we did want to take the time to make sure we got that
equation correct.”
That meant doing a great deal of research before they were able
to confidently make recommendations that would stand the test
of time, including preparing detailed engineering studies, revised
hydraulic modelling (in partnership with the province of Alberta), floodplain mapping, economic studies, and years of public
engagement.
That research became a springboard for what Frigo estimates to
be $700 million to $800 million spent on infrastructure resiliency
projects, “making it one of the most significant flood mitigation
projects not only in southern Alberta but in the world.”
Investments that included installing 2.5-metre steel gates at the
aforementioned Glenmore Dam, which was initially built in 1932
in tandem with the Glenmore Water Treatment Plant to provide
drinking water for Calgarians. For the uninitiated, the additional
2.5-metre may not sound like much. But a far more impressive
number is that in addition to making it possible to better manage
high river flow events in the spring, the dam now has an increased
storage capacity of 10 billion litres.
Frigo enthusiastically shares that as a result of all of the infrastructure enhancements made since the 2013 disaster, “55 per
cent of the total economic risk that the city saw in 2013 has been
extinguished by investments that are now in the ground… and
by 2025, when the Springbank Off-stream Reservoir that’s being
constructed by the government of Alberta upstream of Calgary on
the Elbow river is functional, we’ll be at 70 per cent.”
And they haven’t forgotten about the remaining 30 per cent.
“One aspect (they’re looking at) is that because the Bow River is
a larger catchment (area with a) much more complex river system
to work on… is we are now exploring additional reservoir options
with the province of Alberta,” he said.
Clearly, cities like Calgary, Montreal and, of course, Rotterdam
have made admirable progress in their quest to combat flooding.
However, the challenge that remains for those cities and thousands
more like them from around the world doing their best to cope
with change and the growing incidence of natural disasters such as
heavy flooding is this: there is still much work to be done.
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