Only a team effort can stave off the next B.C. flood disaster: mayor

November deluge underscores need for better flood prevention and management

A sign warns travellers along a stretch of Highway 1 on Sumas Prairie after devastating floods inundated the area in November | Rob Kruyt

Flooding in Abbotsford from a mid-November deluge could cost $900 million in damage and repairs, says Abbotsford Mayor Henry Braun.

But as bad as the flooding was when the Nooksack River across the border in Washington state backed up, that’s not what keeps Braun up at night.

“I am more afraid of the Fraser River than I am of the Nooksack River,” he told BIV. “Because if that dike breaks, that will be 10 times the damage, not just in Abbotsford, but all the way downstream.”

In 2021, wildfires stripped mountain slopes of protective forest cover. This was followed by record rainfall in November that flooded Abbotsford, Merritt and other communities, underscoring the need for better flood management and protection and better co-ordination and funding from senior governments.

It’s something Abbotsford and the Fraser Basin Council have been recommending for some time. The B.C. government acknowledged in 2015 that Fraser Valley dikes needed upgrading, Braun said, but senior government funding has yet to materialize.

“We experienced exactly what we said would happen if these dikes weren’t fixed, and we don’t have the money from property taxes to do this,” Braun said. “So we need the help of both senior levels of government.

“If this is not a wakeup call, then I don’t know what it’s going to take. I guess it’s going to take a flood on the Fraser to get everyone’s attention. One of these days it’s going to breach. The riverbed has been rising over the last 30 years, and we haven’t been adding enough onto the dikes.”

Dikes are the last line of defence in flood management. A lot more needs to be done than just maintaining and raising dikes in flood-prone areas of the province.

In July, just four months before the mid-November deluge, the Fraser Basin Council produced a report that detailed the need for better flood management, prevention, prediction and governance. One of the problems the report points to is decentralized flood management in B.C.

“Since the early 2000s, B.C. has adopted a decentralized approach to flood-risk governance, with authority and responsibility spread across multiple orders of government,” notes the July 2021 report, Investigations in Support of Flood Strategy Development in British Columbia.

“Local authorities carry much of the responsibility for flood management, while federal and provincial governments have limited their roles largely to funding, guidance and post-disaster financial assistance.”

There are 216 regulated dikes in B.C., owned and maintained by 106 government and non-government diking authorities. The report recommends an overarching flood management authority and a funding mechanism for it.

Flooding from “atmospheric river” downpours like the one that occurred in November may not the biggest threat. It’s a heavy spring freshet, combined with rain, that worries Braun most, because if the Fraser River ever bursts its banks and breaches dikes, the damage could be even more catastrophic.

“If we have a heavy snowfall and warm temperatures in the spring, and significant or record rainfall in the Fraser River watershed, we will have a flood,” Braun said. “It’s just a question of whose dike is going to break first.”

The Fraser Basin Council report points out the need for better climate-change modelling specific to B.C., better mapping, flood hazard assessments, flood forecasting and planning and better co-ordination of governance.

Joanna Eyquem, managing director of Climate-Resilient Infrastructure at the University of Waterloo’s Intact Centre on Climate Adaptation, said a national strategy is needed to deal with coastal flooding.

A report she co-authored, Rising Seas and Shifting Sands, talks about strategies, which can include “holding the line” or retreating. In the case of the flooding in Gatineau, Quebec, in 2017 and 2019, the Quebec government has opted to do some retreating.

“There are areas where we’re not building back,” Eyquem said. “And Quebec has limited the amount of assistance people can get for a particular house, and once that money is gone there’s no more assistance to try to encourage the move from these very vulnerable areas.”

The Fraser Basin Council report also talks about “managed retreat.”

But a full retreat in Abbotsford, which would depopulate Sumas Prairie, is unlikely to happen, so dikes and drainage systems will have to be improved.

One option that was proposed by the City of Abbotsford was to drill a tunnel through Sumas Mountain to divert water from Barrowtown, between Abbotsford and Chilliwack, into the Fraser – at an estimated cost of $580 million.

A cheaper option, at $339 million, was to raise dikes.

But no matter what B.C. does, some of its flooding problems stem from causes out of reach on the U.S. side of the border – in particular the Nooksack River.

Better flood control could be achieved by improving dike and drainage along the Nooksack River at a cost of only $39 million, which Canada is willing to pay for, Braun said.

“That doesn’t work for the Americans, I’m told, because all that’s going to do is push the water further downstream and flood Bellingham out.”

In an era of rising sea levels and increasing storm intensities, Eyquem said Canada needs a national strategy, especially in dealing with coastal flooding.

“We don’t have an overall strategy, so what we end up with is piecemeal approaches,” she said. “It’s particularly important for coasts because what you do at one place – if you’re stopping sediment from going down towards another section of the coast – you can actually make things worse for the neighbours.

“You have the Fraser Basin Council, who are trying to do more of this joined-up-system thinking, but at the moment the funding typically goes to local governments.

“Unless they work together, we don’t get these system-based solutions. It’s just treating the problem where it is, rather than doing something that gets to the bottom of why the problem is happening in the first place.”

In a recent press conference, B.C. Public Safety Minister Mike Farnworth said his government acknowledges the need to assume more “involvement” in flood mitigation and dike management.

“We need the collaboration of all levels of government to make sure we address the increasing demands of a challenging climate here in B.C.,” Farnworth said.

– Nelson Bennett

nbennett@biv.com