Restoring the Squamish River estuary can lessen local impacts of climate change
Speak to anyone in Squamish about the weather over the past few weeks and they’ll tell you it’s been a tense and frightening time. Unprecedented rainfall has led to swift increases in the flow of local streams and rivers, resulting in evacuations, mudslides and severe flooding throughout BC.
How can Squamish protect itself from flooding? While there’s no silver bullet, the good news is a major flood mitigation tool exists on our community’s doorstep: the Squamish River estuary. The catch? We need to restore and protect it in order for it to function to its potential.
Estuaries occur where rivers and streams meet the ocean. They work to curb flooding by serving as a sponge, absorbing surging waters and reducing their devastating impact. A recent report from the Squamish River Watershed Society (SRWS) put a dollar value to the ecological services provided by the Squamish River estuary and determined the estuary’s value for “disturbance regulation” - including flood protection - at between $1 million and $5 million per year.
New research published this year by Swansea University also found that “wetlands that grow in estuaries can reduce water levels by up to 2 meters and provide protection far inland.” These findings exceed previous predictions made by scientists and further confirm the key role estuaries play in protecting lives and homes from floods.
You’re likely wondering about the health status of the Squamish River estuary today. While incredible progress has been made through SRWS’s restoration efforts over the past 20 years, there’s still more work to do. A critical next step is to modify the Lower Training Berm, a structure that was put in place in 1971 and designed to redirect the river to facilitate port development, predominantly a large multi-nodal and coal port that never came to be.
Upon first glance you might think the Berm’s redirection of the river could aid in flood mitigation. The reality is actually the opposite. The Berm has fractured the estuary and negatively impacted the ecosystem, driving down Chinook salmon numbers from the 100,000s to the 10,000s. As a keystone species, salmon support the health of the ecosystem and dwindling numbers indicate the health of the estuary is fragile. An unhealthy estuary is unable to properly absorb floodwater, exacerbating the impact of floods and storms.
To add, studies by SRWS and SNC-Lavalin show that the Berm structure doesn’t help with flood mitigation, and that the planned modification will have negligible impact on flood risk in the downtown.
Over the next year, SRWS, along with partners the Sḵwx̱wú7mesh Úxwumixw (Squamish Nation) and Fisheries and Oceans Canada, will actively restore the estuary and modify the Berm through their Restore the Shore project. This initiative will renaturalize over 144 hectares of this valuable estuarine habitat - equivalent to the size of over 200 soccer fields - ensuring that Squamish and our broader community are protected from future flooding.
Even better? SRWS’s work to improve the health of the estuary will lessen the local impacts of climate change and make Squamish a healthier and more resilient community well into the future.