A boil water advisory has been issued for areas downstream of Terrace as residents returned to their homes in the flooded northwestern B.C. city, while several other communities across the province stayed on the alert for rising waters.

Health officials issued the advisory after sewage lagoons in Terrace dumped an emergency discharge into the Skeena River. The B.C. Ministry of Environment authorized the discharge to maintain the integrity of the lagoons.

A street in Prince George is seen on Friday, covered in water from the Fraser River.
(Chuck Stoody/Canadian Press)

Brauns Island, New Remo and Old Remo are the communities affected by the advisory, issued on Saturday. It covers about 100 households that depend on wells for their drinking water.

Besides boiling water for at least one minute, residents can also use an unscented household bleach to disinfect their water, officials said. They advised people to use one drop of unscented bleach for each litre of water.

Meanwhile on Sunday, people from more than 80 homes in a half-dozen flood hotspots throughout the province were still out of their homes. More than 1,100 homes remained on evacuation alert.

More than 200 people were earlier evacuated from their homes in and around Smithers, Prince George, Terrace and the Mount Currie reserve north of Whistler.

Southern Peace River added to flood watch

British Columbia's southern Peace River region has been added to the flood watch list. Communities that are affected include Chetwynd, Tumbler Ridge, Hudson Hope, Mackenzie and Finlay River.

A high streamflow advisory for the region was upgraded on Saturday to a flood watch as a result of intense heat days earlier, which produced extremely high rates of snowmelt.

A flood watch means that river levels are rising and may overflow. A warning means that an overflow appears likely to occur.

Most of the major rivers involved in flooding or flood warnings in the past week saw levels begin to drop on Friday, but they could overflow again with another sudden rise in temperatures, according to Allan Chapman of B.C.'s River Forecast Centre.

Worries over sudden snow melt

About 60 per cent of the mountain snowpack remains and a number of areas are prone to more problems if it melts too quickly, Chapman said.

"Historically the river will flood you once … it'll back off and come back and kick you again," said B.C. Public Safety Minister John Les, who visited Terrace on Saturday with his federal counterpart, Stockwell Day.

Les said people whose homes have been damaged are eligible for disaster financial relief of up to $300,000.

Fuel being shipped to cut-off Prince Rupert

Jim Whyte, the director of operations with the Provincial Emergency Program, said on Sunday that his organization is working on getting fuel to Prince Rupert, which is cut off by flooding.

Whyte said a coast guard vessel has been assigned to bring diesel to the city.

"We've arranged with the co-operation of Petro-Canada for a special barge shipment of fuels and that barge is being loaded in Vancouver," he said.

Whyte said cargo planes are also on standby to ship in supplies if they are needed.