FREDERICTON -- A steady flow of people were at Fredericton's world-renowned Beaverbrook Art Gallery Saturday, but instead of viewing the art inside, they were there to see the flood waters of the swollen St. John River pushing against the outside of the building.

Swollen rivers across New Brunswick continued to rise this weekend, flooding streets and properties and forcing people from their homes in at least four communities.

By Saturday afternoon the St. John River was 1.7 metres above flood stage in Fredericton -- approaching levels hit during the last major flood in 2008 -- and rain was forecast through the weekend.

Sandbags were packed against a number of historic buildings near the river in Fredericton, including the provincial legislature.

The storied Beaverbrook Art Gallery was half-surrounded by water, with the river threatening to get into lower levels.

The gallery has been temporarily closed, and all artwork in the basement has been moved upstairs.

Opened in 1959, the gallery is famous for a collection that includes the work of artists such as Thomas Gainsborough and Salvador Dali.

There have been a number of expansions over the years, including a major addition that opened last year.

Former director Terry Graff oversaw the design and construction of the addition, and was out Saturday morning to check to see if their flood protection measures were working.

"The gallery is built right on the river, but the water has come up right to the expansion and I guess this is the test to see if it keeps the water out," he said.

"A membrane was constructed to keep the water out and there are barriers that have been designed to also block leakage. There was much care and consideration that went into the planning and design, knowing that this could be a risk," Graff said.

However he said there is still the risk of water getting in if sewers and storm drains are overwhelmed.

A number of Fredericton streets -- blocks away from the river -- were partially flooded on Saturday as a result of water being forced up through the storm sewer system.

"The river levels will remain at or near flood stage for the next 48 hours," said Greg MacCallum, director of New Brunswick's Emergency Measures Organization.

The Red Cross had helped evacuate more than a dozen homes in Edmundston, Bathurst, Fredericton and Maugerville, while other residents left on their own to stay with relatives and friends.

Geoffrey Downey, a spokesman for the Department of Public Safety, said many roads and highways are covered by the fast flowing water, and one man near Fredericton had to abandon his vehicle after ignoring a barricade and the vehicle got stuck.

He said the man got to dry land by himself and called authorities to report the vehicle.

MacCallum said it's an offence to move or ignore any of the barricades.

"Washouts are happening and you don't know what that water conceals. It could be deeper than it appears. There could be sinkholes and you could damage a vehicle, or worse," he said.

Officials said there has been significant erosion damage to Highway 144 in the Edmundston area, and much of Route 105 is closed to traffic.

Officials also warned that there may be a lot of animals on the roads that are seeking an escape from the water.

NB Power had cut electricity to more than 100 homes that have been flooded.

A lot of people are venturing along the edge of the river to get a view of the flooding, but MacCallum warned against what he called "disaster tourism."

"I understand the curiosity, but people need to stay safe," he said.

"There's debris in the water. It's fast flowing, and it's not a good place to be right now."

And EMO officials cautioned homeowners with flooded basements from pumping the water out until the water on the outside recedes. They said the pressure on the outside could damage the foundation.