The mayor of a northern Ontario town where a section of the Trans-Canada Highway was washed away by heavy rain says it should be partly reopened within days.

Wawa Mayor Linda Nowicki said Saturday it's expected the southbound stretch of Highway 17 to Sault Ste. Marie will be fully reopened by Monday, although one lane is expected to be open to emergency traffic. Northbound lanes of the highway could remain closed for another week as crews repair 15-metre holes in the road.

She said the town itself is secure, but that officials didn't have a sense of just how much of a toll the rainstorm took on the area's road network.

"It wasn't until late yesterday and early this morning that we viewed the photographs and realized the scope of the damage," she said.

She said the Michipicoten First Nation, a community of about 700 people that sits southwest of Wawa, has been completely cut off, prompting an evacuation that began Saturday afternoon.

"They have no access in or out," Nowicki said.

Ontario Provincial Police said 25 vulnerable members of the Michipicoten community, such as the elderly and those with medical conditions, are being airlifted by helicopter to Wawa under the co-ordination of Emergency Management Ontario.

"[The damage] is quite severe, not so much in the town itself but outside the town," with rain-carved gorges along the Trans-Canada to the north and south of Wawa, CBC's reporter Megan Thomas reported.

Nowicki said the rest of the community will be evacuated in the coming days after the band council decided road repairs would take too long to complete.

She said some residents in other areas around Wawa are also isolated, including five homes stranded between severed sections of highway.

Police said phone lines and 911 service in the communities of Dubreuilville, Hawk Junction and Missinabie remain unavailable after connections were severed in the deluge.

Though the rains have ceased, runoff is still a problem and Wawa remains in a state of emergency, Nowicki said.

"It's a pretty gloomy picture for us," she said.

Nowicki said the destroyed road connections have hit businesses hard in Wawa, noting the local economy was already struggling with the loss of forest industry jobs.

Nowicki and other municipal officials flew over the area Saturday morning to get a better look at destroyed roads and bridges.

The damage to the municipal roads is "equal to or greater" than that of the highway and repairs will cost the town between $5 million and $10 million, she told CBC News.

Does Wawa have that much money?

"Hell no," said Nowicki. "We have a very difficult economic situation to start with and now, with our roads closed, our businesses are suffering."

"Have you ever heard of a Tim Horton's that wasn't busy? Ours is not busy because we don't have the highway traffic coming through," she added.

She said it came as a shock to see the highway washed away by floods caused by the rain.

"This is a one in a 100 year thing," she said, adding the road was in good condition until the foul weather rolled in.

"This is just a freak storm that lasted too long and came too quickly... You end up with lakes on the highway."

Nowicki and the municipality said in a release that they are in the process of asking the province to declare Wawa a disaster area.

The Ministry of Municipal Affairs and Housing was not immediately available for comment.