Lomond, Alberta, Canada
ALBERTA PREMIER’S AWARD OF EXCELLENCE
David Mack, P.Eng.
Rehabilitation of an integral water supply component
McGregor Reservoir is an integral component of the Carseland-Bow River Headworks (CBRH) System that supplies water to 87,000 ha of agricultural land and numerous municipal, industrial and domestic users. Water is diverted from the Bow River via the 65 km long CBRH main canal and is then used to fill McGregor Reservoir and two other reservoirs immediately downstream. Water is then distributed for irrigation through the Bow River Irrigation District canal system. The reservoir is approximately 33 km in length with the north end of the reservoir located about 100 km southeast of Calgary. The reservoir is contained within two earthfill dams (North and South Dams) approximately 16 m in height. The North and South Dams were originally constructed in 1910.
As part of the CBRH system rehabilitation, extensive upgrades were carried out including widening and raising the two dams, replacement of several major flow control structures, construction of an auxiliary spillway and rehabilitation of upstream and downstream connecting canals. Design, contract preparation, construction supervision and commissioning services were provided by the consultant team consisting of Klohn Crippen Berger Ltd. (KCB) and subconsultants Mack, Slack and Associates (subsequently acquired by KCB in September 2007) and MPE Engineering Ltd.
- Aging facilities and low discharge capacity
- Maintain normal flows for irrigation purposes
- Construction of spillway up to 9 m below reservoir level
- New drop structure, low level outlet structure and Travers inlet structure were built
- Cofferdams, temporary reservoir drawdown, staging of the work
- Canal realignment, cofferdams and dewatering systems
- Rehabilitation of two dams and addition of auxiliary spillway
- Irrigation flows were uninterrupted throughout construction
- Construction of a new inlet spillway into Travers Reservoir