The Fraser River will rise significantly over the coming months as record snowpacks melt. The question is how quickly that snow will melt. (Jessica Peters/ Black Press)

Largest April snowpack in decades poses high flood risk to Fraser Valley

Snow packs at highest point in last 20 years; spring weather will determine if flooding occurs

High snowpacks around B.C. are stirring concerns about the high flood risk in many parts of the province – including communities in the Fraser Valley.

Across the Fraser River basin, snowpacks remain 20 to 50 per cent above average. The aggregate snowpack upstream of the Lower Mainland is at its highest level in decades.

It has Abbotsford Mayor Henry Braun watching the situation carefully and hoping the city doesn’t have another emergency to deal with in the weeks and months to come.

“I don’t like what I see up there,” he said.

Jonathan Boyd, a hydrologist with the River Forecast Centre, said the combined index for all upstream snowpacks is the highest it has been since 1999. Records don’t exist before that point.

“We’re not in a great situation in terms of the snowpack,” Boyd said.

It’s not time to panic. But it is reason to worry.

“There’s lots of variables and in order for a record flood to happen, you have to have everything happen in the worst case scenario. But right now, we do know that the snowpack is high enough that it does have that capacity to be there,” Boyd said. “Everyone should be aware the risk is there.

“If the perfect storm for climate and weather conditions occurs, that there could be a risk of very high flows for the lower Fraser Valley,” Boyd said.

The best thing that could happen would be an extended period of quite warm weather. But although sun has blared down for more than a week, Boyd noted that temperatures haven’t been particularly high, and the nights have been chilly.

That means the snow hasn’t been melting much. And the longer it remains in the mountains, the danger increases as the days lengthen and the likelihood of a heat wave rises. The one good thing, Boyd says, is that more snow hasn’t fallen recently to add to that base.

Boyd said the biggest danger scenario includes a sustained run of cool temperatures, followed by a sudden and extended hot spell in May.

“That’s what happened in 1948 when the Lower Fraser flooded considerably,” he said.

Dikes have been beefed up since then, but remain below provincial standards.

One additional domino could increase the severity of any flood.

“What didn’t happen in 1948 is there was no rain. The ultimate variable is if you get a big rain storm falling within the Fraser as it’s peaking.”

If there’s good news, it’s that any flood won’t come completely out of the blue.

Weather forecasters will be able to predict a long spell of hot weather, and preparation can take place as a heat wave is ongoing, in preparation of what is to come. Prince George and Kamloops would also be hit days before the Fraser peaks in the Lower Mainland, providing a clear warning to officials here.

But one other wild card is the health and stability of the dikes that protect thousands of homes and billions of dollars worth of infrastructure in the Fraser Valley. If those dikes hold, the damage from extremely high waters can be minimized. But if they fail, as they did in 1948, all bets would be off.

For Braun, the flood threat is a nagging worry at a time when the city and other municipalities are scrambling to adjust to the implications – both financial and logistical – of COVID-19. Braun has said the city has enough money in reserves to cover the financial implications of tax shortfalls.

But, he noted, “That $43 million could disappear very quickly if a dike goes.”

RELATED: Mayor says Abbotsford has enough cash – and banks already have many residents’ tax money

Do you have something to add to this story, or something else we should report on? Email:
tolsen@abbynews.com


@ty_olsen
Like us on Facebook and follow us on Twitter

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Boulders near Harrison vandalized with derogatory word

Vandalism likely occured between Sunday evening and Tuesday evening

First rainstorm of the season pelting the Lower Mainland

Batten down the hatches as heavy rains, wind, and some localized flooding possible

Man wanted by Abbotsford Police for domestic assault

Morgan Knull, 27, has multiple prior convictions

Irish folk supergroup Kíla set to perform on Saturday

Online concert will be available through Harrison Festival Society

B.C. reports 91 new cases as officials remain worried over ‘clusters of COVID-19

There have now been a total of 8,395 cases in B.C. since the pandemic began

Canada’s active COVID-19 cases top 10,000 as daily new cases triple over the past month

Dr. Tam repeated her warning to young people, who have made up the majority of recent cases

First 8 months of fatal overdoses in B.C. have now exceeded 2019 death toll

Nine people died every two days in August, BC Coroners Service data shows

Liberal effort to reset policy agenda panned by rivals as too much talk, not action

Trudeau said it’s ‘all too likely’ families won’t be able to gather for Thanksgiving next month

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

‘Show us the money’ for cannabis, local governments tell B.C.

Municipal tax, transit revenues falling as costs rise

Young man assaulted, left for 12 hours until help called in Vancouver’s Strathcona Park

Vancouver police are looking to identify the victim as they investigate an assault on Monday evening

‘It’s a boy’: Southern Resident killer whale calf born to J Pod is healthy, researchers say

J35 had previously done a ‘Tour of Grief,’ carrying her dead calf for 17 days

People ‘disgusted’ by COVID-19 election call, B.C. Liberal leader says

Andrew Wilkinson speaks to municipal leaders from Victoria

Most Read