Parks Canada is draining the water under the ice surface on the Rideau Canal today.
The National Capital Commission (NCC) urges the public to stay off the surface as the ice conditions are unsafe.
In order to drain the canal, the logs at the top of the Ottawa locks will be removed. This will eventually destabilize and collapse the ice.
The 40th canal skating season lasted 36 days before mild weather forced the closure of the world's largest skating rink in late February.