WC142 MayJune 2025 - Magazine - Page 13
TOP 50 PROJECT
Springbank O昀昀-Stream Reservoir
Calgary project ups ante for 昀氀ood control
BY SAUL CHERNOS
ORE THAN A DECADE AGO, a rapidly melting snowpack in Alberta’s Rocky
Mountains combined with a series of heavy
rainfalls to produce the most intense flooding Calgary had experienced in more than a
century. On June 20, 2013, the Bow and Elbow Rivers crested to record levels and breached their banks,
forcing more than 100,000 residents to evacuate and
inundating much of the city, including its business
core. Floodwaters damaged light-rail tracks, pooled
inside tunnels, and undermined roads, shutting public transit, schools and other services for extended
periods, and hydro crews spent more than a week
restoring power. In all, the city’s Flood Recovery Task
Force tallied $409 million in damage to municipal
infrastructure and the event ranked among the costliest natural disasters in Canadian history, with damage
region-wide estimated at $5 billion.
The numbers pretty much tell the story of the
once-in-a-lifetime flood. Flows along the Bow River
peaked at 2,400 cubic metres per second, eight times
the regular rate, while the Elbow River inflow peaked
at 1,240 cubic metres per second, a dozen times
the norm. Below the Glenmore Dam, outflow was
measured at 700 cubic metres per second, 20 times
its average. Emergency crews erected temporary
flood barriers and lowered the Glenmore Reservoir’s
water level just enough to mitigate some of the worst
impacts while still ensuring continuity in the supply
of safe drinking water. When things finally settled
M
Getty Images
Saul Chernos is a freelance
writer for Water Canada.
down, the affected municipalities and the Province took
stock of the damage and set about planning resilience
work designed to mitigate the risk of history repeating
itself. Thus, from the waters of the Calgary Flood, was
borne the Springbank Off-Stream Reservoir (SR1),
a $912.5-million flood control project on track for
completion this spring.
Located alongside the Elbow River 15 kilometres
beyond Calgary’s western border, the project broke
ground in 2022. Referred to as a dry reservoir because
its centrepiece is a catchment basin on dry land designed
to temporarily hold excess water when flooding occurs,
SR1 will work in tandem with Calgary’s Glenmore
Reservoir to accommodate water volumes equal to the
2013 flood and thus reduce flow rates on the Elbow,
downstream. “Think of the Springbank reservoir like
a big bathtub,” says Frank Frigo, who oversees climate
and environmental management for the City of Calgary.
“It will allow a significant portion of the flow from
the Elbow River to be diverted into storage, where it
can be held until natural flows recede, and then it can
be released at lower, non-damaging rates later on.”
Springbank will offer roughly four times more storage
than Glenmore, the city’s only other significant reservoir,
and the two combined will provide enough storage space
to contain another, comparable 200-year flood. “I would
describe it as one of the key investments in the city and
region’s overarching flood resilience plan,” Frigo says.
While the 1,450-hectare (3,700-acre) dry reservoir
is the key piece, a 4.7-kilometre diversion channel
from the Elbow River and a 29-metre-tall earthen dam
approximately 3.8 kilometres long and 300 metres at
its widest are essential to its function, as are a series of
hydraulic structures and two overpass bridges above
the diversion channel. With 70,000 cubic metres of
reinforced concrete and five million cubic metres of
earthwork, the project is unquestionably enormous.
WATER C AN ADA • M AY/JUNE 2025
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