View of Calgary's downtown core looking west from the Elbow River escarpment, showing intensive development on the floodplains in both the Bow and Elbow river valleys

No significant flood has occurred in Calgary since 1932 and, consequently, very few people consider flooding to be a major hazard. As a result of this lull in flood activity and of the attractiveness of living near Calgary's waterways, development in Calgary's river valleys has increased dramatically since 1932.

Dikes along the riverbanks within the city and dams along the Bow River upstream from the city will control much floodwater in the case of heavy flows. However, if another 100-year flood (a flood of such size that it has 1 chance in 100 of occurring in any given year), such as the flood of 1897, were to occur today, the Bow River would see its normal flow rate rise from 92.9 m³/s to 2265 m³/s, more than 24 times its normal volume. The potential damage has been estimated at $131 million in 1996 dollars.

Estimates of flood damages are calculated by considering water velocity and flood extent. As obstructions such as houses and other man-made obstacles decrease water velocity, the height and width of the floodwaters increase. Given that development in our river valleys has increased dramatically since 1932, the extent of flood damages would be exponentially much higher if another 100-year flood were to occur today.

-Nathan Kneisel-

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