Klohn Crippen Berger (KCB) was retained to review the generation potential estimates and provided detailed design of the Zeballos Lake Hydro Project on the west coast of Vancouver Island.
The project utilizes the head between Zeballos Lake and the lower reach of Maraude Creek, which drains from Zeballos Lake. Zeballos Lake was formed more than 1200 years ago by a rock fall that blocked the Maraude Creek valley. Under natural conditions there is leakage under and through the rock fall “dam” and occasional overtopping of the dam. KCB’s scope of work included review of the geotechnical conditions at the outlet of Zeballos Lake and development of a methodology for sealing the landslide debris at the outlet to provide a “watertight” barrier. KCB developed the detailed design for the project, including drawings and specifications.
The Zeballos Lake Hydro Project comprises a single submerged power intake in Zeballos Lake, a 55 m-deep intake gate shaft, a 900 m-long power tunnel with a “hot tap” into the lake bottom, a 500 m-long fish penstock, a fish powerhouse with a single 3 MW Francis unit, a 550 m-long, 1.8-m diameter low pressure penstock, a 5.3 m-diameter surge tank, an 1100 m-long, 1.8 m-diameter, high pressure penstock, and a main powerhouse with two 10 MW Francis units. The fish penstock and powerhouse return water to Maraude Creek just below the rock fall, for riparian flows, while the main powerhouse uses the full head available to the outlet of Maraude Creek. The total capacity of the site is 23 MW and the development will provide 100 GWh/year of energy for the Vancouver Island region. KCB prepared drawings and specifications for the intake, tunnel and “hot tap,” penstocks, surge tank, powerhouses, switchyard civil works, tailrace, and transmission line.
- Review of geotechnical conditions
- Development of slide sealing methodology
- Detailed design
- Construction engineering services