City of Waterloo to evaluate storm water management alternatives
During the past 5 years the City of Waterloo, Ontario has been receiving an increasing number of reports of localized flooding of residential properties and roadways in some of the older neighborhoods of the city. In one particular area, a sag in the road way and low-lying adjacent properties have resulted in significant flood damage to several homes and pooling of water in excess of 1 m deep across several lots.

Using the results of the integrated 1D and 2D urban flood modeling of the study area, the City was able to clearly identify the only viable solution to the flooding problem, and to effectively communicate these findings to the public. As result, the City’s engineering staff has recommended an accelerated schedule for the permanent solution rather than risking time, budget and public backlash by pursuing ineffective short-term measures.

At an early stage it was decided to adopt an approach that included a dynamic coupling between the 1D sewer system and a 2D overland flow as this coupling was essential to decribe the two way exchange of water between the sewer system and surface. Futhermore, it facilitated a more accurate representation of the 2D overland drainage as well as helped to identify the dominant processes causing the flooding, and to evaluate the effectiveness of potential flood mitigation measures.