Hay River Mayor Kandis Jameson says she is desperately trying to convince remaining residents to leave the town's Vale Island while they still can.
Hundreds of residents have left their homes in the Hay River region since floodwater arrived at the weekend, but some people have chosen to remain in the West Channel and Old Town.
While some residents holding out say they have good reason to do so, Jameson said the scale of the unfolding disaster meant a full evacuation had to happen immediately.
"We're going to lose that road. Then you won't have a choice," Jameson said.
"This is unprecedented, and it's unsafe. It's very, very scary. The message is get off and get off now. I can't stress this strongly enough. Get off. Do it now."
Jameson said that while the rate of flow has slowed, water is still rising everywhere.
Vale Island resident Darlene Lamb had, until this morning, planned to stay on the island. She said a personal call from Jameson changed her mind.
"The mayor just called me and asked for everyone to get off the island immediately and stressed how serious it is. So I am leaving and I thanked her for the call," she said. "There is a wall of ice and water built up that’s off the charts and never seen before."
Residents can attend a public meeting at the community centre to find out more about the town's flood response at 7:30 p.m. on Tuesday. The centre is offering support for evacuees, as is the Soaring Eagle Friendship Centre.
Caitrin Pilkington, Local Journalism Initiative Reporter, Cabin Radio