More than 100 workers on the Site C project were laid off Monday while another 15 recover from an outbreak of a gastrointestinal virus.
Peace River Hydro Partners confirmed 120 workers were laid off due to "ongoing workforce management."
"As with any construction project, the work and number of workers will vary from month-to-month based on the scope of work being performed," Amber Harding, the company's spokeswoman, wrote in an email.
"When scopes of work are completed, PRHP transfers as many employees as possible to different areas of work before laying employees off. With this round of lay-offs, heavy equipment operators and labourers were the main job classifications impacted."
There may be future employment opportunities for the workers, Harding noted.
The layoffs come after 72 workers were let go from the site last week because of a work stoppage and safety concerns related to ongoing slope excavation works on the north bank of the Peace River.
There were 2,522 people employed on the dam project in some capacity in May 2017, according to BC Hydro's latest available employment statistics.
Stomach flu at Site C
Meanwhile, 15 workers at the Site C dam site have caught the stomach flu, BC Hydro says.
The company says measures have been put in place at the project's work camp to prevent the outbreak from spreading.
"This includes notifying workers in the camp and on site about the outbreak and promoting hand-washing and the importance of reporting illness," Hydro said in a statement.
"Enhanced cleaning of common touch surfaces is being conducted and the medical clinic, the camp operator and contractors will continue daily monitoring of existing conditions and any new cases."
The 15 employees who are currently sick are not working, and will return when cleared by medical staff, Hydro says.
There was a previous outbreak of gastrointestinaal virus at the work camp in January.