PROJECT SUMMARY

The original 12 Street Southeast Bridge was constructed in 1908 to carry horse and buggy, as well as pedestrians, to St. George’s Island. Over the next 100+ years, the bridge became an important connector link for vehicles and pedestrians. Due to its deteriorated condition, The City elected to replace the original truss bridge with a wider, haunched bridge that improved flood resiliency and safety for all traffic modes. The old truss bridge was removed in 2017; construction of the new bridge began in 2016 and it was opened in December 2017.

OUR ROLE

Matrix Solutions Inc.’s scope of work included the following:

• establishing the bridge grade
• designing the bridge piers and abutments and all instream work requirements
• completing the environmental assessments and obtaining the regulatory approvals
• conducting environmental monitoring and field engineering during the instream construction
• providing flow and river ice forecasting while the instream berms were in place

OUTCOME

This was The City’s first bridge constructed across the Bow River after the record flood of 2013. Matrix established the key hydrotechnical design criteria during a period of ongoing hydrologic and hydraulic model updates by The City and Province which inform flood policy and hydrotechnical design. Matrix lead consultation efforts with key stakeholders including the City to achieve buy-in on the hydrotechnical design criteria given local flood risks and stakeholder interest following the 2013 floods.

Concurrently we were providing hydrotechnical engineering services for the Calgary Zoo Flood Protection project, also on St. George’s Island; we coordinated our hydraulic analyses to ensure there were no net increases to the local flood risk caused by the projects. Our role in the regulatory approvals was critical to keeping the project on its accelerated schedule. The project won two Awards of Merit in Sustainable Design and Transportation Infrastructure – Transportation Structures at the Consulting Engineers of Alberta 2019 Showcase Awards.