One week after the malfunction at the Cleveland Dam left a North Vancouver man dead and his son missing, Metro Vancouver says human error was to blame.
Multiple people were rescued and two were swept into the Capilano River when the dam’s spillway suddenly opened on Oct. 1, deluging the riverbanks where anglers were out enjoying salmon season.
“While the review continues, we can now confirm that the clearest contributing factor was human error related to programming of the control system for the spillway gate at the Cleveland Dam,” said Metro Vancouver CAO Jerry Dobrovolny in a statement released Thursday morning. “Metro Vancouver takes responsibility for this mistake and our deepest sympathies go out to those affected by the tragic loss of life.”
In the statement, Metro says it is now committed to ensuring another similar accident never happens again. Senior management is calling on expert advisers to assess current practices and give independent advice on how to strengthen the dam’s operations and maintenance systems.
Following a similar disaster in in 2002, WorksafeBC ordered Metro Vancouver to “swiftly” develop, implement and enforce a written “lockout policy” that would stop the dam’s spillway from opening accidentally and conduct a risk assessment study to protect the health and safety of the public and workers.
“Following technical recommendations by experts, Metro Vancouver upgraded the Cleveland Dam spillway gate from a mechanical to fully automated control system in 2002 and there have been subsequent upgrades. Metro Vancouver has not experienced a similar unintended release of water in almost two decades,” Dobrovolny’s statement added. “We are entirely compliant with all related WorkSafeBC orders and requirements.”
Metro will also consider adding early warning alarms, the statement said, an idea that was rejected in 2003 on the grounds it would be ineffective and would annoy residents in the neighbouring Grousewoods community.
The regional authority conducts safety reviews of the dam every seven years, which includes an assessment of public safety. This was last done in 2016. Earlier this year, the regional government completed a safety assessment focused on the dam and the river system, the geography of the space, and potential hazards considering downstream users and activities, and demonstrated consistency with industry best practices.
The spillway is now being opened again, and will likely stay that way throughout the rainy winter season, according to Metro.