Heavy flooding in British Columbia turned deadly Saturday as a washed out bridge on the road to Whistler claimed at least one life. Two other people are believed missing.

Whistler is now completely cut off and the flooding has forced the evacuation of nearly 500 people in the towns of Pemberton and Squamish. Both communities are under a state of emergency.

The storm is expected to continue into Sunday and could bring another 90 millimetres of rain to some parts of the province's south coast.

The heavy rains forced B.C. Hydro to open the flood gates of the Daisy Lake Reservoir after a state of emergency was declared in the Squamish area.

About 150 people, who live on the banks of the Cheakamus River just downstream from the dam, were forced to leave their homes. Squamish is located about 60 minutes north of Vancouver.

Pemberton Mayor Elinor Warner said that more than 120 people were evacuated from Pemberton on Saturday. Another 300 people were forced out their homes on the nearby Mount Currie reserve.

"They have been moved to higher ground at the high school near the reserve," said Cathi Piazza, a spokeswoman for the B.C. Provincial Emergency Program.

The highway, which runs from Vancouver to Pemberton, was closed Saturday in three locations.

"(Pemberton's) isolated and these bridges aren't going to be fixed, so unless the water goes down we have no movement of goods," Warner said. "The only way in and out is through helicopter."

Crews are working to stabilize the road and install a temporary bridge. Still, it could take more than 48 hours before the road is reopened.

Elsewhere, the rains have forced some farmers in the Fraser Valley to move their livestock to higher ground.

The Pacific Northwest has been drenched with heavy rain over the past week. Several rivers in Northern Washington state have started to overflow their banks.

Several of the swollen rivers, including the Nooksack run through southern B.C. Abbotsford farmers on the Sumas Prairie have been placed on alert in the event the Nooksack River should overflow.

Meteorologists are calling it a 100-year storm and said it's happening because rain is moving north from the tropics.

Dozens of accidents have been reported in the Vancouver area and at least one death has been attributed to the heavy rains.

The deluge has quickly changed a dry summer into a soaking autumn. As much as 200 millimetres have fallen on some communities.

One fallout of the record-breaking rains is that drinking water is getting darker in the Vancouver area. Health authourities are suggesting that anyone with a weakened immune system should boil their water.

With a report from The Canadian Press