An atmospheric river is drenching coastal British Columbia, triggering localized flooding as voters head to the polls for the provincial election.

Photos and videos posted to social media show brown floodwaters rushing over streets throughout Metro Vancouver, including West Vancouver, the North Vancouver community of Deep Cove, Surrey, Burnaby, and Port Coquitlam.

The province鈥檚 River Forecast Centre issued an upgraded flood warning for the Coquitlam River in Metro Vancouver on Saturday, while maintaining a flood warning for waterways on the west coast of Vancouver Island.

Flood watches remain up for the rest of Vancouver Island, and the south and central coasts, while high streamflow advisories cover the north coast and large sections of the southern Interior along the Alberta boundary.

Mike Little, the mayor of the District of North Vancouver, says crews had been bracing for rain, working to clear leaves and debris from culverts and storm drains, but the intensity of the weather system caught officials by surprise.

Little says about two dozen homes in high-risk areas have been evacuated, but the mayor was not aware of any injuries resulting from the flooding.

He says the rain was expected to ease overnight, giving crews an opportunity to catch up on clearing drainage channels, but more downpours are expected Sunday.

In neighbouring West Vancouver, police posted a video on social media showing a surge of brown floodwater flowing down a sloping city street.

In the Metro Vancouver community of Langley, RCMP issued a warning about a possible sinkhole, saying heavy rain had compromised a roadway鈥檚 stability.

Mounties also issued an advisory about a mudslide with debris and fast-moving water that has forced the closure of a road on the outskirts of Coquitlam.

The BC Hydro outage map shows more than 6,000 customers without power across the Lower Mainland and the Sunshine Coast heading into Saturday evening, along with nearly 3,000 in the central Interior and about 500 on Vancouver Island.

A handful of voting sites in Kamloops and Langley, as well as on Hornby, Denman and Mayne islands, were temporarily closed in the morning due to power outages.

All have since reopened, and while the electoral office for Port Moody-Burquitlam was experiencing a power outage, Elections BC says the site is open for voters.

Later Saturday, Elections BC issued an update saying the voting site at Alexander Robinson Elementary School in Maple Ridge East was temporarily closed due to a power outage, and officials were directing voters to alternative locations.

BC Ferries warned that high winds in the forecast could affect service on northern Georgia Strait and northern Vancouver Island, while DriveBC reported a number of highway and road closures due to washouts or flooding.

The atmospheric river will also roll over the province鈥檚 southern Interior, with prolonged periods of heavy rain expected to persist through Sunday, and high streamflow advisories are in effect for several regions in southeastern B.C.