McLymont Creek Hydroelectric Project

CLIENT: Coast Mountain Hydro (Altagas Renewable Energy Inc.)

The proposed hydropower project is a 66 MW run-of-river plant located on McLymont Creek, a tributary on the north bank of the Iskut River, located about 100 km north of Smithers, British Columbia. The design foresees an intake facility that comprises a 24 m long by 3.5 m high inflatable rubber weir, a 6 m wide primary sluice, a 2 m wide secondary sluice, and a headrace canal directing a design discharge of 30 cubic meters/second .

NHC teamed with Gygax Engineering Associates Ltd. (GEA), Struthers Tech, BGC Engineering, and Wyllie and Norrish to conduct detailed design engineering for the McLymont Creek Hydroelectric Project. NHC was responsible for the hydraulic design of the intakes and the coordination of the general arrangement of the intake structures with the team.  In addition, NHC’s professionals conducted transient analyses of the penstocks and established an economic model.  NHC also assisted in the design of the tailrace while advising the team on specific hydraulic issues such as rip rap sizes, culvert geometries, design levels, and sizes for crossings. 

Furthermore, NHC was also retained to construct and test a 1:16 scale mobile-bed physical hydraulic model to examine the hydraulic performance of the proposed intake structures and refine the design of the structures to improve performance and reduce costs. The model was used to make refinements to minimize the amount of sediment entering the power tunnel, reduce headlosses, minimize vortex activity at the tunnel portal, and improve the flow pattern within the headrace canal.