INNOVATION November-December 2017

T he team of engineers and ecologists who led the restoration of Mark Creek, which flows directly through the middle of the City of Kimberley, sound justifiably proud of the fact that they actually managed to pull off the task they set for themselves: to replace an outdated and dangerously unstable concrete flume with a far safer and more natural-looking flood mitigation measure for a bare bones budget of $7 million—with the side benefit of enhancing daily life for residents and fish alike. “We took it from a 400 metre long concrete box and turned it into a flowing river,” says Evan Sykes, P.Eng., a geotechnical engineer with EXP Services Inc. Sykes’ job during the Mark Creek Flume Flood Management and Stream Rehabilitation Project was to ensure slope stability in “steep, relatively tight areas”—essentially the width of an average road, bounded by private property on both sides—and to design rock drop structures to slow the velocity of water pouring down the creek from the Purcell Mountains during the spring freshet. RACING AGAINST TIME It was a devastatingly large rain-on-snow event in 1948 that sparked the development of the original Mark Creek flume. That flood swept away dozens of homes and several whole streets, and the city pledged that it would never happen again. The concrete structure they built (and then re-built after another major flood in 1956), while heavier

Copcan crew installing aquatic habitat features in the snow of late 2012. P hoto : EXP S ervices I nc .

T op right : The old concrete flume being held up by blue light standards after it began to fail. P hoto : C ori B arraclough . B ottom right : New Mark Creek channel stands up to the same storm that devastated Calgary in 2013. P hoto : C ori B arraclough .

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