Another storm is expected to batter the rain-soaked coast of British Columbia early Sunday, targeting many areas already under boil-water advisories because of heavy rains.

The warning not to drink tap water remained in effect Saturday for about 900,000 residents in the Lower Mainland and two communities on Vancouver Island.

Parks crews and utility staff will be on call as British Columbia braces for more bad weather.
(CBC)

The advisory was partially lifted Friday, but remains in effect for several centres, including Nanaimo, Chemainus, Vancouver, Burnaby and North and West Vancouver.

Seymour, Capilano reservoirs swamped

Two million people were advised to boil their water on Thursday after high levels of silt ended up in two reservoirs that supply the region.

Officials in the region described the levels of discolouration from suspended silt as "unprecedented" and said they couldn't guarantee that home filtration systems would prevent illness from drinking the water.

The advisories still in effect were not expected to be lifted until at least Monday.

The Greater Vancouver area has recently endured record rainfall, destructive winds and flooding.

Emergency crews on standby

Patricia Leslie, communications manager with the District of West Vancouver, told CBC News that parks crews and utility staff will be on call in case they're needed on Sunday.

"Should the weather turn out to be a little more violent, we'll be able to jump into action more quickly," she said.

Wednesday night's storm brought winds of more than 100 km/h and rainfalls exceeding 110 millimetres in some areas. The latest system could produce winds gusting up to 90 km/h.

"It's going to be a very messy weekend," said CBC meteorologist Teresa Fisico, who added that northern coastal areas, just south of Prince Rupert, will be hardest hit, along with the west coast of Vancouver Island.

The B.C. River Forecast Centre has warned people to stay away from coastal rivers. River levels have fallen since Wednesday, but the centre's Allan Chapman said they'll likely rise again as the second storm moves in.

Harper keeps watch of situation

Prime Minister Stephen Harper said Saturday he hopes to speak to Premier Gordon Campbell this weekend about the province's water advisories.

"We're watching the Vancouver situation closely," Harper told CBC News during a break in the APEC forum in Vietnam. "[We're] obviously a little concerned and we're hoping it'll be resolved shortly."

In another development, the Greater Vancouver Regional District is working on a project to treat water from the Capilano and Seymour reservoirs, which it hopes will make boil-water advisories like those issued in the past week no longer necessary.

Johnny Carline, the district's chief administrator, said a $600-million filtration plant should be up and running late in 2008.