The project consists of the rehabilitation of an existing earthfill dam currently out of operation due to excessive leakage and potential risks of liquefaction. The spillway capacity needed to be increased by a factor of three due to new CDA Guidelines and Dam classification regulations. A demand study was required in combination with a review of the hydrology to confirm that flows and lake storage is sufficient to meet irrigation and domestic needs for the downstream Licensees. Consideration was given to build a new dam, low level outlet and spillway immediately upstream of the existing alignment, and build an additional upstream channel within the lake bottom linking the two reservoirs to increase storage capacity. KCB services included detailed designs, tender documents, geotechnical investigations, liquefaction and seepage assessments, environmental overview assessment (the site is very sensitive and on native land), and construction services. GIS mapping was implemented for visual support during public hearings. Sustainability and Safe Design was a key factor considered during the design phase.
- Gabions were used instead of conventional concrete (better aesthetics and fit into the environment);
- Confined space structures were eliminated from the original design (intake tower now replaced by a sliding gate);
- Local sources of material were maximized.
Note that these cost saving initiatives were completed in agreement with the Penticton Indian Band (PIB) and Aboriginal Affairs and Northern Development Canada (AANDC), and that training opportunities were offered to the PIB staff (environmental, administration, and dam operating staff)
Seismic Evaluation and Spillway Design/Construction.
Project goal was to address DSR requirements for a seismic evaluation and for a new spillway to accommodate the IDF. During construction, KCB assigned a Resident Engineer for the full duration of the main construction activities (1 year period) to provide quality assurance and coordinate design adjustments due to unforeseen conditions.