Peguis First Nation has declared a state of emergency due to rapidly rising river levels threatening many homes.
The reserve, home to about 7,200 people, is located about 190 kilometres north of Winnipeg on the Fisher River.
The river went up almost one metre in just a few hours, say officials.
"It has reached a critical point where there's hundreds of homes that are currently affected and [water] has reached our highway — our only access in and out of Peguis," said Kristy Wilson with the Peguis Emergency Centre.
Declaring a state of emergency enables the reserve to access federal disaster assistance funds and force the evacuation of affected homes.
However, Wilson said the evacuations, so far, are not mandatory. But people are strongly encouraged to leave.
Once they are registered at the emergency centre on the reserve, they will be found a place to stay in Winnipeg.