Calgary Zoo Flood Mitigation

ISL Engineering and Land Services Ltd. & Associated Engineering

Calgary, AB

The 2013 flood was among the worst in Calgary’s history, causing $50 M of damage to the Calgary Zoo. The joint consulting team of ISL Engineering and Land Services and Associated Engineering was retained by the City of Calgary to lead the design and implementation of a flood mitigation plan to protect the zoo’s infrastructure and secure its future on St. George’s Island in the Bow River. This was a significant challenge, with the team working to understand both the overland and underground flooding. Preserving Calgary’s first developed park space, sensitive riparian habitat, mature trees and native vegetation were key factors in selecting the least invasive and most effective solution. A unique mitigation system was chosen with complete overland and subsurface isolation of St George’s Island. A sheet pile cofferdam perimeter wall was combined with a dual-purpose dewatering system to delicately manage interior stormwater runoff and groundwater during the annual flood season. Combined with a once-in-a-lifetime renewal of its supporting servicing infrastructure, the flood mitigation system will allow the Calgary Zoo to confidently remain in its iconic Bow River home and continue to operate as a world class facility and leader in wildlife conservation, for the enjoyment of generations to come. For the jury, this project – focused on problem solving and redundant design – showcases the true effectiveness of technical engineering.