Flood-ravaged Abbotsford watching Nooksack River from U.S. 'like a hawk' as heavy rains near

The mayor of Abbotsford, B.C. says he is confident the city's rebuilt dikes and sandbagged pump station can handle a barrage of heavy rains in the forecast until Sunday afternoon — but not if the Nooksack River from Washington State overflows.

Abbotsford issued an evacuation alert for the city's Huntingdon Village, urging residents to prepare essential items in case they are ordered to leave on short notice this weekend.

• Read more about the flooding situation across southern B.C.

Mayor Henry Braun told reporters Saturday afternoon the flood-ravaged city is watching the U.S.-Canada waterway "like a hawk," because it is a difficult-to-predict wildcard without knowing how saturated the surrounding soil is.

He spoke Saturday morning to officials in Whatcom County, Wash., which saw the U.S. National Guard deployed this weekend.

'The rain we can handle ... We can't handle if the Nooksack overflows'

If the river does breach its banks, Braun said the already-saturated Fraser Valley farmland could potentially see worsened flooding.

"We have done everything we can in a very short period of time," he said Saturday. "Now the unknown factor is how much water is going to come [from] south of the border."

"The rain we can handle — I'm pretty confident of that —  but we can't handle if the Nooksack overflows and starts emptying again into Sumas Prairie."

Waters are expected to enter into the west side of the Sumas Prairie near Huntingdon Village on Sunday, according to the city.

Braun cautioned that stopping the Nooksack River's flow is unrealistic because it would require a "dike that is 18 feet high" on the border. Instead, he said, sandbagging to protect buildings is the priority.

"Quite frankly, we don't know what's going to happen," he said. "But we're going to watch that Nooksack like a hawk."

'Nooksack River will come over with less resistance,' fears U.S. mayor

South of the Canada-U.S. border, Whatcom County is predicting the Nooksack River will reach a "moderate flood stage" on Sunday.

The mayor of Sumas, Wash., Kyle Christensen, told CBC News the floods his town experienced two weeks ago from the atmospheric river event broke three dikes, and one remains "still not fixed" despite constant work by the U.S. Army Corps of Engineers.

"With all this water — and it's building up — once the Nooksack River goes over tomorrow, which is what we're predicting, then it's going to be a lot more water for us deal with," Christensen said in an interview.

"The concern is that the Nooksack River will come over with less resistance because of the damage from the flood from last week."

Whatcom County, which includes Sumas, issued a statement Saturday warning residents about the risks posed by coming rains.

"Damage to levee systems from previous storms may result in greater impacts to the floodplain areas than typical at these river levels," the county said in a statement. "There is much uncertainty as a result of last week's floods."

As a precaution, the county added, U.S. National Guard troops are being deployed "to assist local agencies" by sandbagging, delivering supplies and supporting the communities of Sumas, Everson and Nooksack.

"People are tired," mayor Christensen told CBC News. "You know, this has been going on a long time and here we're going to get hit by a second wave."

'Heavy downpours can cause flash floods'

According to CBC meteorologist Johanna Wagstaffe, the current forecast models show much uncertainty, but suggest an increasing potential for more flooding events by Tuesday.

"Rainfall totals, unfortunately, will be extreme," Wagstaffe said. "This definitely has the potential to see impact both with additional overland flooding and new landslides."

Federal meteorologists issued a rainfall warning for the Fraser Valley and south coast Saturday, with Environment and Climate Change Canada noting "heavy downpours can cause flash floods and water pooling on roads."

Through Sunday afternoon, weather forecasts predict 70 millimetres of rain over southern sections of the Fraser Valley on Saturday, but up to 120 millimetres closer to the mountains.

Rains should ease up on Sunday, but effects on river levels could be seen several days later.

The City of Abbotsford posts its most recent flood, evacuation, and other emergency information on its website.

Provincial flood warnings and advisories are available from B.C.'s River Forecast Centre.

For information on evacuation alerts and orders issued by various authorities across the province, visit Emergency Management B.C.'s Twitter feed or website, which also offers updates and supports available for evacuees.