After a week of water woes caused by heavy rain, Vancouver is bracing for another weather nightmare: snow. 

Up to 30 centimetres of snow is in the forecast for the Lower Mainland through Monday, Environment Canada said Saturday.

Air Canada said it expects delays and cancellations at Vancouver airport on Sunday, and advised travellers to check the status of flights before leaving for the airport.

The boil-water advisory, issued 10 days ago, is expected to remain in effect for Vancouver, Burnaby and most North Shore communities until at least Monday.

It was issued after a major storm muddied the region's two largest reservoirs — the Capilano and the Seymour reservoirs in the North Shore mountains — with silt.

Homeless shelters expect high demand

As light snow began falling in Vancouver mid-afternoon Saturday, the city's social service agencies were searching for more beds for the homeless in anticipation of a pre-Christmas cold snap.

Capt. John Murray of the Salvation Army said the organization has accommodations for 237 people in the city's poverty-stricken downtown Eastside, and was stockpiling bedding.

"We anticipate we're going to be full to overflowing," Murray told the Canadian Press.

Murray said a multi-purpose room and a dining area had been converted into a sleeping space, with mats on the floor.

Snow in other parts of B.C. forced the province to issue travel advisories.

Officials also warned drivers to be aware of snowy conditions in the areas west of both Glacier and Yoho national parks in eastern B.C.

On the Trans-Canada Highway in the Vancouver suburb of Coquitlam, a vehicle sliding into a median on the six-lane section of road caused a chain reaction of collisions.

With files from Canadian Press