Two weeks after the June 2013 flood, Sunnyside’s stormwater system received a rainfall that couldn’t be discharged to the Bow River, as most of the outfall gates were closed to protect the community. The City of Calgary worked with Associated Engineering to examine this unusual flooding sequence and propose resiliency upgrades.
When historical analysis showed that high-intensity rainfall and high river levels had been independent, the team suggested an innovative dual level of service approach, substantially reducing the cost of improvements. A first for the City, this approach sets a precedent for other floodplain communities seeking cost-effective stormwater management solutions.