Some New Brunswick residents have been warned to get out of their homes and seek higher ground, or hunker down to wait out the flood that could take a week or more to subside.

Residents near the St. John River south of Fredericton are most at risk. Fredericton Fire Chief Bob Martin said officials are warning residents in the city's riverside communities to be careful.

"We'll go door to door with handouts, to let everyone know we consider them to be in a possible threat area," he told CTV Atlantic. "Right now, we just want them to be very much aware that the situation with the rain is changing on us all the time."

The rising waters are already high enough to lap the lawns of homes close to the river, and western parts of the province are expected to see between 60 to 88 millimetres of rain on Tuesday.

Andy Morton, deputy director of the province's Emergency Measures Organization, said that would be more than enough to prevent many people from leaving home until levels recede.

"Today is the go out or stay in day," Andy Morton told CTV's Canada AM on Tuesday.

Some families have already evacuated, while others have decided to stick out the flood close to home.

According to the Emergency Measures Organization website, the water level in Fredericton is expected to increase from 7.1 metres to 7.8 metres between Monday and Wednesday this week.

Price said the rain is expected to raise the river level above flood levels from 2005, approaching levels not seen since 1973.

In Maugerville, east of Fredericton, the water level is at 6.23 metres and is projected to increase 6.4 metres by Wednesday.

Flooding is an annual problem for the region during the spring thaw.

Morton said about 100 people have already left their homes voluntarily and he's expecting many more to do so today.

Maugerville residents Helen Ladds has lived beside the St. John River for 40 years. Despite the warnings, she has refused to leave her home.

"I'm quite worried about it, but I don't know. I'll wait a couple days to see," she said.

A number of roads in the area are already under water.

Morton suggested those planning to wait out the high waters stock up on clean drinking water, food, and any necessary medications.

"Be very alert of water coming in and the impact it will have on your electrical system," he warned residents.

The St. John River runs along the western side of New Brunswick.

The premier has said the government will help those who experience major floor damage, provided the province declares a natural disaster.

The province's Public Safety Minister John Foran said the situation has not yet reached a state of emergency.