Can the answer to future flooding be found in resurrecting an ancient lake?

followers the recent floods in Abbotsford and on the soil of the Semá:th (Sumas) number one carry amelia moore nation in brits Columbia, some researchers are renewing their calls to bring part of the ancient Sumas Lake back to life.

The idea could mitigate the growing risk of flooding in the region. However, the restoration of floodplains raises significant economic, political, and social implications.

Under heavy rain, Kwilosintun (Murray Ned), a member of the Semá:th First Nation, whose ancestral territory is located in the Abbotsford region of British Columbia, walks along the last vestige of an ancient lake.

"This is the Sumas River. Pretty much what's left of the remnant of the Sumas Lake," says Kwilosintun, executive director of the Lower Fraser Fisheries Alliance.

In mid-December, flooding hit the region, surfacing memories of the catastrophe four years ago. In 2021, waters submerged roads, farms, and homes, causing more than $450 million in insurable property damage in British Columbia.

In Abbotsford, the deluge submerged many farms. But it also revealed a glimpse of the area’s past.

"It was both a bit tragic in terms of, chaos the water was creating for the people. But for me, I was able to go and kind of harmonize, take a look at what our ancestors would have seen, and maybe embrace it for a little while," says Kwilosintun.

Before the 1920s, the Sumas prairies were covered by a lake. A floodplain whose area varied from 3,600 hectares to more than 10,000 hectares, the equivalent of nearly 20,000 football stadiums.

To increase farmland space, local authorities drained the lake. The project  subsequently profoundly altered the environment and displaced the Semá:th.

"It meant everything to us. So when they drained it, essentially we didn't have the resources to sustain ourselves after that," explains Kwilosintun.

As climate change drives flood risk in the Fraser Valley, Kwilosintun believes that remembering what this territory once was could be one solution to flooding.

"I think mankind has to figure out a way to harmonize versus trying to challenge Mother Nature, building bigger dikes and larger pump stations all the time," Kwilosintun said.

Kwilosintun and Tara Martin, a professor from the University of British Columbia, published a study in 2024 examining the feasibility of restoring Sumas Lake.

The study concludes that allowing the lake to return would involve a planned relocation strategy at a cost of approximately one billion dollars for property buyouts.

"We compare that price tag to what's being proposed by the City of Abbotsford, the price tag for building new dikes for an additional pump station, for upgrades to the pump station exceed $2.4 billion," states Martin, who leads the Conservation Decisions Lab.

Despite these figures, Martin says the study was quickly dismissed by local authorities.

"I think overall there has been very much a faith in traditional business as usual solutions to try to deal with this issue rather than thinking outside the box. The challenge is that none of those traditional solutions are guaranteed to work."

In an email, the City of Abbotsford states that it prioritizes flood protection measures over the option of putting the territory back underwater, because "re-flooding would be an entirely different direction and one that would involve all governments."

The city also indicated that it submitted a $1.6 billion funding request in July 2023 for its long-term flood prevention plan to the Disaster Mitigation and Adaptation Fund (DMAF). 

This plan includes a new pumping station. In 2024, the federal government rejected this $1.6 billion proposal.

Ottawa replied by email that since its launch, the DMAF has received hundreds of applications from across the country. However, the fund has exceeded its available resources. 

Kwilosintun wants to see the federal government more present in the city's adaptation efforts.

"We need the federal government at the operational scale, not just sending funds this way. We need them at the table, to be decision makers in the process."

The authors acknowledge more economic analysis, such as quantifying the financial impact on agricultural land and a full assessment of costs related to restoring the lake. 

Agriculture remains a critical part of the region’s economy, and Kwilosintun doesn’t downplay this reality.

"We don't want to see people displaced, but at the same time, we want to see some semblance of balance with the ecosystem, with the spirit of the lake, with the lake itself."

For Kwilosintun, the lake is gone but a spark of life remains.  

"I think it's always been a lake, and I think it's going to be a lake into the future. From my perspective, within this century, I think it's going to return one way or the other," he says.

---

---