Authorities have so far confirmed one death after torrential rains and mudslides destroyed roads and left several mountain towns isolated.
At least three people are missing.
Provincial Premier John Horgan described the calamity as a once-in-500-year event.
The massive floods and mudslides also severed access to the country's largest port in Vancouver, disrupting already strained global supply chains.
Some of the towns are in remote mountain areas with limited access and freezing temperatures.