Duncairn Dam -Engineering Services for Rehabilitation of the Downstream Low Level Gate System

Agriculture and Agri-Food Canada (AAFC) is the owner/operator of water-control infrastructure and land associated with twenty-nine (29) water storage projects in southern Saskatchewan. These works were among the many built between 1935 and 1960 as part of the Prairie Farm Rehabilitation Administration’s (PFRA)’s legislated mandate to help stabilize and contribute to the economic security of the drought prone regions of western Canada. AAFC manages these facilities in accordance with the principles and practices of the Canadian Dam Association (CDA) Dam Safety Guidelines (2007). One such project is the Duncairn Dam which was constructed by the Prairie Farm Rehabilitation Administration (PFRA) in 1942 on Swift Current Creek approximately 30 km southwest of the City of Swift Current. The original riparian gate was replaced in 1997. Since that time, the gate and downstream transition have suffered cavitation damage. In the spring of 2016, an inspection of the gate showed an approximately 300mm portion of the top of the gate frame was lost. (The loss of the portion of the gate frame is not believed to have been caused by cavitation. Rather, it is theorized that an object became wedged between the gate and the frame when the gate was open. As the gate was closed, the object placed sufficient force on the frame to damage it.) AAFC seeks to undertake a rehabilitation of the downstream low level gate system. The downstream low level gate system, includes the gate, stem, hoist, gate frame, thimble and transition, which is hereinafter referred to as the “system”. The rehabilitation seeks to maintain the flow capacity of the existing system, while at the same time eliminating cavitation. This Statement of Work (Appendix B) details the engineering design, construction and project management services required to complete the rehabilitation of the downstream low level gate system at Duncairn Dam.