The Site C Clean Energy Project is the third dam and hydroelectric generating station on the Peace River in British Columbia. Klohn Crippen Berger (KCB) and AtkinsRéalis (AR; formerly SNC-Lavalin) formed a joint engineering team to provide the multidisciplinary expertise needed to design and construct this world-class project. Acting as the prime design consultants, KCB and AtkinsRéalis undertook design of the key dam site components such as the earthfill dam, diversion tunnels, approach channel, drainage tunnels, power intakes, penstocks, the generating station, and spillways, all designed and constructed in compliance with industry guidelines and best-practice. Site C is designed to deliver 1,100 megawatts (MW) of capacity totaling an 8% increase to BC Hydro’s current energy supply, Site C will generate approximately 5,100 gigawatt hours (GWh) of electricity annually. This is enough to power 450,000 homes or 1.7 million electric vehicles supporting the province of BC’s long-term electricity demands. Site C represents a long-term investment in clean and sustainable energy, ensuring a reliable power source for generations to come. From its inception, BC Hydro, KCB and AR prioritized safety-by-design, integrating measures to protect construction workers, future operators, the public and the environment. This commitment extended beyond the design and construction phases, emphasizing safety and efficiency throughout the dam’s operating lifecycle.

Collaboration was a cornerstone of the project’s success. Facilitated by BCH, KCB and AR took part in the engagement process including consultations with First Nations and stakeholders which served as critical checkpoints, ensuring transparency and alignment throughout the project lifecycle painting a positive stakeholder relationship. This coordinated effort underscores Site C’s commitment to safety, environmental stewardship, and community engagement positioning the project as a cornerstone of B.C.’s clean energy future.

KCB and AtkinsRéalis designed the Site C Clean Energy Project with a focus on mitigating the complex geotechnical challenges through the project components and layout. Given the weak clay-shale foundation, the design team implemented a roller-compacted (RCC) buttress to strategically replace the surficial weathered and unstable shale bedrock with a robust foundation, providing stability across the powerhouse and spillway structures and forming the right abutment for the earthfill dam. The stability was further enhanced by installing a series of vertical piles deep into the rock below the RCC buttress along with implementing a liner system to improve the water tightness of the approach channel and drainage systems to minimize seepage into the foundation.The alignment of the Site C spillway was required to be perpendicular to the direction of incoming river flow creating 90 degree bend for flow entering the spillway.

By leveraging extensive physical hydraulic modelling and computational fluid dynamics (CFD) simulations, the final design included features such as unsymmetrical guide walls, a deep stilling basin with a large downstream weir, and discharge structures at low, mid, and high elevations to achieve the required spill capacity while optimizing overall geometry.

Through our long-standing involvement, KCB and AtkinsRéalis helped shape the Site C project by providing technical leadership and ensuring a transparent and collaborative approach to infrastructure development.

The Site C reservoir was successfully filled with first power produced in late 2024. Site C will generate enough electricity to power 450,000 homes or 1.7 million Evs, supporting B.C.’s long-term energy needs. Site C also drives economic growth, creating 13,000 person-years of employment during construction, 160 jobs annually, and $2 million in grants and school taxes. Its long-term investments in maintenance will sustain additional employment while ensuring clean energy for future generations.