Engineering Services for the Rehabilitation of Shoreline and Embankment at Harris Dam

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). Harris Reservoir is an off-stream irrigation storage reservoir located in Section 5-10-26-W3, approximately 10 km south of the Town of Maple Creek, Saskatchewan. The reservoir was created in 1955 by the construction of a main embankment, a number of dykes and a diversion works. Erosion of the shoreline banks began shortly after the construction of Harris Reservoir; however, recent years with high precipitation events and subsequent consistently high reservoir levels appear to have increased the rate of shoreline erosion. Sediment is released into the reservoir which accumulates and plugs one of the irrigation outlets. The bank recession is also encroaching on AAFC’s access road to this outlet as well as land not currently owned by AAFC. The upstream face of the main embankment of Harris Reservoir has areas of thin and poorly graded riprap, a number of scarps near the crest and has numerous areas containing heavy vegetation (trees and shrubs). As part of its long term commitment to the management and dam safety of these water control assets, AAFC is planning the rehabilitation of the areas experiencing extensive shoreline erosion and the main embankment during fiscal year (FY) 2017/18. This Statement of Work (Appendix B) details the engineering and environmental services required to complete design for the rehabilitation of the shoreline and embankment at Harris Reservoir.