Expert Warnings of a Flood Like This Go Back 20 Years

Having warned for more than two decades about the high risk of flooding in the Fraser Valley and how climate change could make that vulnerability even worse, Steve Litke says it was “stressful” to see this week’s events.

“Terrible situation, for sure,” said Litke, the director of water programs for the Fraser Basin Council. “I just feel so bad for what people are going through.”

Litke started at the non-profit FBC in 1998 shortly after it formed as a collaboration between federal, provincial, local and Indigenous governments, as well as the private sector and civil society. Its mandate is to advance sustainability in the Fraser Basin and throughout the province.

“I don’t recall in my couple decades working in this area such widespread and significant impacts from a single atmospheric river,” Litke said. Common in B.C. in the fall and winter, an “atmospheric river” is an intense flow of moist air that brings heavy precipitation.

“[It’s] a reminder that we need to do more to strengthen our approaches to reducing future flood risk and to take into account climate change impacts on that and also to look at the wide range of flood hazards that exist in the region,” Litke said.

Heavy rainfall starting last weekend led to flooding, including in the Fraser Valley and on Southern Vancouver Island, and to landslides and washouts that closed several highways and cut Metro Vancouver’s transportation links to Eastern Canada.

As of Wednesday the provincial government estimated that some 17,775 people had been evacuated due to impacts from the flooding and said there are evacuation orders for 5,918 properties, with another 3,632 on evacuation alert.

The flooded region included many dairy and poultry farms that provide about half of the province’s supply. Thousands of animals died in the flooding and many more remain in danger, Agriculture Minister Lana Popham said.

While politicians used words like “unprecedented” and “unexpected” to describe the storm and its effects, it was the kind of disaster Litke had long warned about.

In 2006, when journalist Chris Wood wrote about B.C.’s vulnerability to climate change, he quoted Litke saying that a major flood like the Fraser Valley had in 1894 would lead to dike failures and disastrous consequences for the many people living below the dikes on either side of the river.

“The rest of us should be concerned because of the effects on infrastructure,” Litke said at the time. “The Trans-Canada goes along there, the two railways. Oil and gas pipelines could be breached. The hydro corridor. You’re certainly affected, even if your house is intact.”

Also, he said 15 years ago, climate change made it difficult to know whether future floods would be anything like those of the past. “How valid is that historical peak flow? Climate change is an obvious big question. Something bigger could occur.”

Knowing the vulnerability and the risk made it stressful to watch this week’s storm, Litke said in an interview Thursday.

While work has been done over many years to mitigate flood risk, it hasn’t been enough.

“We’re working hard with others, with different jurisdictions, different orders of government, to try to get ahead of it,” Litke said. “In this case we haven’t. Hopefully it does strengthen our resolve to get ahead of future events, like a large historic Fraser River flood that would impact many more communities along the lower Fraser.”

The vulnerability is in part related to past land-use decisions that included draining Sumas Lake to create farmland and allowing development in low-lying areas.

“A lot of that historical development, or historical settlement, occurred before we had the depth of awareness and understanding that we do today,” Litke said. “Partly it’s dealing with the legacy of past decisions.”

Going forward there are various steps that can be taken to reduce risk, he said, adding that it will take multiple approaches integrated together in a holistic way.

“When we’re doing this kind of flood planning we want to be thinking about the social, environmental, economic and cultural consequences and benefits of flood risk reduction,” he said. “It’s not just about fighting the water back, but planning in a way that looks after all of those values that society has.”

One piece of it is to keep improving the system of dikes and flood protection that already exists. According to the FBC’s website, the Fraser Basin has about 600 kilometres of dikes, 400 floodboxes and 100 pump stations.

With more heavy rain in the forecast, the Canadian Army began work Friday on a two-kilometre levee to replace a broken dike near Abbotsford and protect the Sumas Prairie from further flooding.

That dikes will sometimes fail should be expected, Litke said.

“Dikes are built to a certain standard and larger events can occur, in which case there is that potential for failure in diking systems, so we need to also do well on the land-use planning and flood-proofing and resilience side of things.”

That means being careful about what kinds of building and activities are allowed in areas where there’s a high risk of flooding.

“If development or infrastructure is going to be approved in flood hazard areas, it perhaps can be built above predicted flood levels or can be designed in a way that can be more resilient and resistant to flood damages,” Litke said.

In low-lying areas, some kinds of agriculture, recreational areas, and parks and protected areas can get through a flood with relatively little damage and few consequences.

There’s also a need for nature-based solutions, Litke said, including keeping wetlands that can help store water and slow the spread of a flood.

Others have pointed out that in many places heavy logging and wildfires have reduced the capacity of the land to absorb water and changed how it flows across the landscape, increasing the risk of floods.

This week’s events made it clear the risk is widely shared, far beyond the areas that are actually flooded, Litke said. Not everyone was flooded in Merritt, for example, but everyone had to evacuate when flooding caused the city’s wastewater treatment plant to fail.

Similarly, when roads and railways close and supply chains are interrupted, it affects everyone, he said.

“Floods are natural events, whether that’s on the coast or the Fraser River or from heavy rainfall during autumn, so in that sense it’s a question of ‘when’ not ‘if’ flooding will occur,” Litke said. “Because floods are natural and predictable, there’s also a need in addition to the preventative side to have good capacity for emergency response and recovery ultimately.”

While there have long been projections that floods would become more frequent and larger, both on the Fraser River and with sea level rise, as average temperatures increase with climate change, it seems to be coming sooner than expected, he said.

“I think it would be wise to anticipate more of these kinds of events, and to build resilience against these kinds of events,” he said. “I wouldn’t want to mistakenly assume this is a one-off or an anomaly. I think we should be strengthening our resolve to address these kinds of events.”

It’s been good to see people pulling together to recover from this storm, he said, but hopefully it inspires new efforts to prepare for the next ones that are sure to come.