VANCOUVER -- Flooding closed Highway 1 in British Columbia's Interior for most of the day Thursday, causing heavy traffic delays on two lake ferries as travellers sought alternate routes.

The closure came amid flood watches and warnings prompted by heavy rainfall across much of the Interior.

The highway closed before 8:30 a.m. as a result of flooding between Woods OH Bridge and Summit Lake OH Bridge, roughly 10 kilometres west of Revelstoke.

Crews were on scene working to reopen the highway before 9 a.m., but nearly 12 hours later, there was still no estimated reopening time, according to DriveBC.

"Probability of the highway reopening tonight is low," the provincial agency tweeted at 7 p.m.

The prolonged highway closure caused waits of more than an hour at the Upper Arrow Lake Ferry, which carries Highway 23 across Upper Arrow Lake, as well as at the Needles Ferry, which carries Highway 6 across Lower Arrow Lake.

In a news release, Emergency Management BC urged the public to prepare for localized flooding as a result of the heavy rainfall swelling rivers in the Interior.

Flood warnings were issued Thursday for the Upper Fraser River, including its tributaries and around Prince George, as well as the Quesnel River, according to the province.

Flood watches were also in effect for the following areas:

  • the Peace region;
  • northeastern B.C.;
  • the Cariboo region, including tributaries and areas around Williams Lake and 100 Mile House;
  • the Chilcotin River and its tributaries, including Big Creek and the Chilko River;
  • the Fraser River from Prince George to Boston Bar; and
  • the North Thompson River, South Thompson River and Thompson River at Kamloops.

A flood watch means river levels are rising and will approach or may exceed bankfull, while a flood warning means river levels have already exceeded bankfull or will do so "imminently."

"Water levels rising in these areas are high and very fast moving, so people need to take extra caution right now and be prepared," said Mike Farnworth, B.C. Minister of Public Safety and Solicitor General, in the release. "I want to stress that any sort of recreation on these waters is highly dangerous right now, so let's make sure we're not taking any unnecessary risks."

Earlier, heavy rain across Southeastern B.C. prompted the province's River Forecast Centre to issue a high streamflow advisory for the region.

The centre says its modelling forecasts the Upper Columbia rivers reaching five- to 20-year flows in response to the wet weather.

The public is advised to stay clear of the fast-flowing rivers and potentially unstable riverbanks during the high-streamflow period.

The centre has posted flood warnings for the upper and middle Fraser River basins, including the Quesnel River, while lower-level flood watches are in place for the Chilcotin and Thompson rivers.

With files from The Canadian Press