Western Canada: Flood warnings and evacuation alerts in parts of B.C. as dissolving snowpacks fill rivers

Good morning. Wendy Cox in Vancouver this morning.

Rivers, creeks and streams across the province are swelling with the dissolving snowpack in the mountains, prompting days of flood warnings in various parts of British Columbia. Some 580 people were living under an evacuation alert on Friday, meaning they needed to be prepared to leave at a moment’s notice.

Ian Cunnings, executive director of regional operations for Emergency Management B.C., told a news conference that it’s important for people to pay close attention to the weather and warnings. Although there are no evacuation orders, “there are continued risks still ahead of us.”

Many of those living with a bag packed by the door and sandbags outside of it are being protected from surging waters by dikes that no authority claims. Justine Hunter wrote this week about the more than 100 dikes across British Columbia – including some in major urban areas – that neither the province, nor the local municipality takes responsibility for.

The orphan dikes, as they’re called, are increasingly likely to fail in catastrophic and expensive ways, Justine writes. But the people living behind them probably don’t know that.

Justine visited a South Vancouver sea dike in the city’s Southlands neighbourhoods, where the owners of equestrian estates can enjoy a stroll along the top of a three-kilometre embankment that a 2020 survey of the structure concluded has a strong likelihood of failure.

The City of Vancouver blames the province for the slapdash construction of the Southlands dike, which was built by the provincial government in the 1940s as part of an emergency works project, according to a statement provided by Jimmy Zammar, the City of Vancouver’s Director of Urban Watersheds, Sewers and Drainage. But when it raised the shoreline, it didn’t obtain easements or right-of-way agreements. As a result, the responsibility to maintain the dike remains with individual property owners, he said.

Along the right bank of the Thompson River in Kamloops, an earth-fill dike protects a tidy, modest residential subdivision that is home to more than 1,000 people, and 376 buildings with a collective property value of $141-million. Homeowners have constructed pools, sheds, stairs, patios and homes close to the structure, some within about four metres of the base of the dike.

The engineers who inspected it could not determine when the structure was constructed or who built it, likely as an emergency response to a significant flood event. The engineers found erosion, side slopes that are too steep, dense vegetation throughout the structure, and signs of beaver activity, which can let water in and eventually destroy the structure. With its unknown pedigree, it was not assigned to a diking authority.

Greg Wightman, utility services manager for Kamloops, said the orphan dike is just one of several in the city, and the cost of repairing even just the most high-risk ones would be more than $55-million.

“We’ve tried on a couple of occasions to work with the province to get repairs done, and the province is unwilling to make the repairs or get the approvals to do that,” he said in an interview.

In Kelowna, a pair of dikes were built in response to a 1948 flood in Mission Creek. The meandering waterway was confined to a straightened channel, providing flood protection for a developing area with dikes on either side of the creek.

The dike on the left bank is considered functional, but with major deficiencies. It protects residential, commercial and agricultural properties worth more than half a billion dollars, according to the risk assessment.

The dikes are mostly on city property, but Kelowna’s civic officials have refused to take on maintenance of the structures on either side of Mission Creek: They don’t want to weaken their argument that the deficient structures are solely a provincial responsibility.

The flood risks are not well known. The province released the Fraser Basin Council’s summary report on orphan dikes, which it says is intended for a public audience. However, the individual, site-specific detail reports are not publicly available: They are deemed technical and list dikes only by an identification number, not location. They were made available to The Globe and Mail on request.

When the seemingly sturdy dike designed to protect Princeton from the Tulameen River breached in two places in the catastrophic floods of last November, siblings Dian and Danie Brooks nearly lost their home. It has been deemed unliveable and the pair have no idea what their long-term future will bring.

Ms. Brooks says she has written e-mails and made phone calls to every level of government, from the Regional-District of Okanagan-Similkameen to provincial government officials to federal government representatives, but no one will take responsibility for the failure of the orphaned dike, she says.

“Our house has been completely flooded, and nobody seems to care.”

This is the weekly Western Canada newsletter written by B.C. Editor Wendy Cox and Alberta Bureau Chief James Keller. If you’re reading this on the web, or it was forwarded to you from someone else, you can sign up for it and all Globe newsletters here.