Heavy rain, possible flooding in B.C. Interior this week: River Forecast Centre

A new low-pressure system is expected to bring potentially long periods of heavy rain to parts of the province this week, according to the B.C. River Forecast Centre, which has upgraded flood risk alerts for the Thompson River and Upper Columbia regions.

The centre says a flood watch has been issued for the Thompson River, from Kamloops to Spences Bridge, as continued snowmelt and runoff have made river levels "very high" for this time of year. 

A high streamflow advisory has also been issued for the Upper Columbia region, including the Kicking Horse River, Illecillewaet River and river flows around Invermere, Radium, Golden and Revelstoke.

The low-pressure system is expected to pass through Wednesday into early Thursday, with rainfall of up to 40 millimetres in North and South Thompson, Cariboo Mountains and Upper Columbia watersheds.

With the heavy rain, river levels could reach record-highs for the season, which could lead to flooding, according to the centre. Warm temperatures over the next week could trigger rapid snowmelt which could also contribute to flooding.

Last week, Dave Campbell, head of the River Forecast Centre, said the delay in snowpack melt this year means a greater risk of flooding will persist into July.

Meanwhile Environment Canada meteorologist Armell Castellan noted the forecast for July shows much hotter conditions in B.C., which could increase flood risk.

The City of Kamloops activated its Emergency Operations Centre (EOC) on Monday as a "precautionary measure that enables the City to respond quickly should the situation worsen, and allows access to additional resources as needed."

Meanwhile the City of Kelowna remains under a State of Local Emergency enacted last Tuesday, after the Mission Creek topped its banks, flooding roads, yards and basements.

In the Elk Valley, the District of Sparwood extended its State of Local Emergency until June 27. Last week it partially rescinded an evacuation alert for residents of the lower Lodgepole Mobile Home Park, while an alert for the Mountainview Mobile Home Park remains in place.

A flood watch remains in effect for the Liard River and its tributaries between Fort Nelson and Watson Lake in northeastern B.C, north and south Thompson regions, the Shuswap area and sections of the Quesnel River east of Williams Lake.

Despite the general easing of conditions, EmergencyInfoBC says evacuation alerts are ongoing for areas west of Tulameen and in Harrison Mills west of Hope.

A localized flooding alert has also been issued by the North Okanagan village of Lumby.

A flood warning is the most serious in a three-tiered alert system used by the forecast centre and means flooding is expected. A flood watch, on the other hand, means river levels are rising and flooding may occur. The high streamflow advisory is the lowest of the three levels issued by the River Forecast Centre.