Lessons learned: BC Hydro releases Site C report

Key Takeaways:

• BC Hydro’s Site C “lessons learned” report highlights major reforms for future capital projects, including tighter contract management, early and transparent risk quantification, and integrated schedules to better manage complexity and claims.
• Despite delays and cost overruns, Site C’s team says it achieved strong operational and safety outcomes — completing six generating units with no fatalities over 65.6 million work hours — and demonstrated sound geotechnical performance through comprehensive monitoring and adaptive engineering.
• The project directed over $876 million in procurement to Indigenous-designated companies, achieved 23% Indigenous vendor participation, and established multiple benefit and training initiatives — a model BC Hydro plans to replicate in future projects.

The Whole Story:

After it faced massive delays and the cost more than doubled, the Site C project has gone under the microscope to determine what went wrong and what could have been done better.

BC Hydro’s Site C dam “lessons learned” report sets out what the utility says it will do differently on future capital builds, starting with tighter contract management, earlier risk quantification and heavier geotechnical instrumentation through commissioning. The document emphasises picking contract models that match complexity, running an integrated schedule across all packages, managing interfaces in real time, and escalating claims to senior decision-makers early rather than at close-out.

Their conclusion was that one of the main culprits was failing to budget for “low-probability, high-consequence risks.”

The report comes after project went well over budget and faced significant delays. The project was approved in 2014 with a budget of $8.775 billion, and construction began on July 27, 2015. After a 2017 provincial inquiry by the BCUC, the government decided in December 2017 to continue and in February 2018 lifted the budget to $10.7 billion, driven largely by higher main civil and generating station/spillway costs following two left-bank tension cracks, a one-year river diversion delay and related claims and indirect labour needs.

In February 2021 the estimate rose to $16 billion with an in-service date of 2025, reflecting pandemic disruptions that erased roughly 60% of the summer-2020 season and right-bank geotechnical issues that required foundation, watertightness and drainage enhancements. The project commissioned units progressively through 2024–25, placing the sixth unit in service on August 8, 2025, and is now substantially complete.

On risk, the report calls for a single, shared register backed by transparent cost- and schedule-risk analyses and routine reporting that makes low-probability, high-consequence threats unmistakable to governing bodies. It notes Site C consolidated registers mid-project, increased the cadence of CRA/SRA cycles and bolstered specialist staffing, moves the utility links to keeping the schedule on track during pandemic disruptions.

Geotechnical management is framed as continuous work rather than a discrete phase. Through first filling and spring thaw, engineers met frequently to review data from instruments such as piezometers, inclinometers, extensometers, thermistors and pendulums; shoreline performance remained within expectations with only minor erosion and sloughing at previously identified historical slide areas. “This performance demonstrates the quality of design and construction,” the report states.

The utility also points to permitting and engagement practices it says worked, including a centralised permitting team, a schedule tied to regulatory milestones and regular Environment and Permitting Forums with potentially affected Indigenous communities. BC Hydro says it is already adapting this model for other initiatives, including the North Coast Transmission Line.

The report underscores economic participation: more than $876 million in procurement went to Indigenous-designated companies, with a peak Indigenous workforce of 539 and a 23% Indigenous-affiliated vendor participation rate by count. Capacity-building included pre-skills training, employment sessions and Indigenous awareness training, alongside eight Impact Benefit Agreements and a Traditional Use Fund.

Operationally, the document records that all six generating units and key electrical systems are commissioned and running reliably. During filling and early operations, continuous winter spill was required to balance flows with Peace Canyon; heaters and daily gate movements were used to prevent ice bridging at temperatures near –30 C.

Safety outcomes cite 65.6 million work hours from July 2015 to July 2025 with no fatalities and a lost-time injury frequency of 0.17, compared with WorkSafeBC’s 2.32 average for heavy construction over the period. The report notes serious incidents did occur and resulted in inspections and administrative penalties largely directed at contractors; mitigation included planned verifications, near-miss tracking, risk-based third-party reviews and close coordination with WorkSafeBC.

BC Hydro closed by saying several permitting and engagement practices from Site C are being ported to upcoming builds.