The Calgary Weir is part of the Western Headworks system situated on the Bow River just 3 km east of downtown Calgary. The headworks system, including the headgate, sluiceway, weir, and fishway structures, were constructed in 1975 by PFRA, and are used to supply water to the Western Irrigation District. The 152 m-long ogee weir represents the only barrier to boaters and fish passage within the 100 km-long reach of the Bow River between Bearspaw Dam and the Carseland-Bow River Headworks. The weir also created an extreme drowning hazard that has claimed several lives over the years.
The primary objectives of the Calgary Bow River Weir Project are to enable river passage for non-motorized boats and enhance fish passage while maintaining its water supply function. The main features of the project consist of constructing a low water channel for novice boaters and a high water channel for more experienced boaters. A divide island separates the two channels. Within each channel, a series of boulder drop structures and pools are incorporated to create the desired flow conditions. Modifications to the weir include incorporating slots at specific locations for boat and fish passage, and adding a concrete infill to change the ogee profile to create the desired flow conditions. Detailed physical and numeric hydraulic modeling was incorporated in the design of the boulder structures and riprap erosion protection. Construction was completed on schedule and under-budget.
- Performed geotechnical and hydrogeological assessments
- Prepared layouts and designs of hydraulic structures, including weir modifications and fish passage provisions
- Developed construction sequence, contracting strategy, and implementation schedule
- Participated and provided input and support on stakeholder and regulatory issues
- Prepared tender documents
- Providing construction administration and QA inspections
- Project management