Klohn Crippen Berger was retained by the City of Calgary to design and implement flood mitigation measures to protect the community of Elboya on the right bank of the Elbow River, along Riverdale Avenue and through Stanley Park. KCB conducted the conceptual design and assessment of a number of backflood prevention options to act in conjunction with the previously proposed temporary and permanent flood barriers.

Due to significant site constraints, KCB recommended the use of inline check valves, and worked closely with the City’s Asset Maintenance and River Engineering groups to develop an acceptable design approach which involved installing inline check valves downstream of the last manhole in the stormwater sewer system at Outfall E48 and Outfall E49A. The valves offer flexibility to accommodate potential changes in the flood barrier alignment, and operate without human intervention, reducing demands on City forces during a flood emergency. The valves were installed in summer 2017.

KCB was also asked to assess permanent flood barrier options to protect the community from overland flooding. KCB completed conceptual design of an earth berm, a concrete barrier, and a combination of the two and developed high level engineering and construction cost estimates. The cost estimates were then compared to the City’s flood damage assessment tools and recommendations for future consideration were provided. The recommendations also included consideration of the site constraints, landowners concerns, the impact on Stanley Park and other infrastructure.

Services

• Conceptual design of permanent flood barrier options
• Conceptual and detailed design of backflood prevention measures
• Construction cost estimating
• Preparation of project specifications
• Contract administration and field services