As British Columbia prepares to build back from recent devastating floods and improve defences against ones in the future, it’s facing new calls to consider the infrastructure’s effects on fish and wildlife.
Dikes and pump stations, the core elements of modern flood defences, can come at a massive cost to the welfare of aquatic species, according to Lina Azeez with the Watershed Watch Salmon Society.
Standard pumps, like the one used at the Maple Creek Pump Station in Port Coquitlam, kill fish every time they’re used, she said.
“It’s pulling fish, it’s pulling amphibians and gridding them up in the machinery of the pumps,” she said.
Dikes, too, provide safety to communities but come with a tradeoff for fish, she said. The society estimates flood control measures, including more than 600 kilometres of dike, have affected about 1,500 kilometres of waterways in the Lower Fraser region that forms a critical habitat for beleaguered salmon populations.
“These are waterways the salmon would have used for a variety of different reasons from spawning, to rearing to overwintering,” she said.
“These waterways are salmon nursery habitats. We need to give salmon the best chance of survival out in the ocean. They need to know how to be good hunters, they need to be big enough.”
Martin Rosenau, an instructor at BCIT’s Fish, Wildlife and Recreation program, said dikes and flood control infrastructure are responsible for up to 95 per cent of the lost wetlands in the Lower Fraser, with historically catastrophic effects for salmon.
“This was a huge loss,” he said.
“It must have been well over 50 per cent for some of these populations, and maybe even 100 per cent for some of the smaller ones in the Lower Fraser.”
Now, with the public purse wide open as the provincial and federal governments look to a future of anticipated extreme weather and climate change impacts, Azeez said it’s time to look at doing things differently.
Pump stations can be equipped with more expensive but fish-friendly pumps.
“It’s downloaded to the local governments to take care of that work, and they can’t often afford to do so. They need to compete with their fellow municipalities to apply for funding to do this work,” she said.
Dikes, she acknowledged, are a bigger problem, given the reality of where communities and farming regions are already established.
She said rethinking how to place dikes to give rivers more room to flood and move as they naturally want to do can be a part of the solution, along with restoring wetlands that can absorb water and help mitigate some of the worst flood impacts.
“We’re more looking at opportunities to set them back from the river so that the river is not as channelized,” she explained.
“A channelized river means increases in flow and a higher chance of mass amounts of erosion that will actually undercut a dike, and actually breach a dike which is dangerous.”
She also argued that more radial solutions, such as relocating populations in the highest-risk areas may need to be considered, something she acknowledged would involve asking “hard questions.”
“We want government to take a leadership role and actually listen to what experts have been saying — they’ve been saying it for decades now,” she said.
“We want to make sure it’s not your typical archaic methods of managing waters which is to bulled up more dikes, put in bigger pump stations, and not consider some nature-based solutions.”