This past November was a wild ride of emotions, from grief to rage to helplessness to hope. As I watched communities, roads, and bridges wash away, unstable scarred mountain sides crumble, and rivers overspill their banks, breaching dikes and refilling ancient lake beds, I wondered at the choices we’ve made as a society.
I have been working on the issue of flood control in the lower Fraser River and its impacts on wild salmon since 2016. Since the flooding, I have been overwhelmed by journalists and others, all wanting to know how the floods have impacted wild salmon, and what should be done about it.
Although flooding is an essential part of a healthy river ecosystem, November’s extreme floods, caused by global warming and warmer oceans, took a heavy toll on wild salmon and their habitats. Many Fraser salmon populations were already at historic lows, and for spawning chum and coho, the raging waters made laying and fertilizing eggs very difficult. For salmon that had already spawned, flood waters may have destroyed their redds, and washed away their eggs. Additionally, most of the massive pump stations moving water from behind the dikes into the river are not fish-friendly, meaning they kill large numbers of fish that pass through them. Not to mention the pollution from chemical spills, sewage and dead animals. It could take salmon several generations to recover.
Stranded Salmon during the Chilliwack, BC flooding. | Credit ©Prossy Froese
Billions of recovery dollars are about to flow into BC communities to rebuild and upgrade after these catastrophic storms. How we decide to spend this money could affect wild salmon for generations to come.
More than 1,100 km of dikes protect BC communities, the majority of them, about 600 km, in the lower mainland. Floodplains are low-lying, often highly fertile habitats. Seasonal flooding deposits large amounts of nutrient-rich sediments. This fertile soil also makes these areas attractive for human settlement.
The atmospheric rain event and associated flooding in November 2021 overwhelmed the dikes in the Fraser Valley. In this photo blueberry fields are inundated with water. Connected Waters is working with agricultural organizations to find ways to support farmers adapt to climate change.
In the lower Fraser, most of the flood infrastructure, installed to protect homes and farms from flooding, also blocks salmon from accessing waterways that once provided valuable overwintering and rearing habitat. 150 pump stations and gates block over 1,500 km of habitat in the lower Fraser River alone.
With this massive investment in flood control, we have an opportunity to rethink our approaches to how we live with water and adapt to floods. By incorporating natural defences to manage flooding, we can protect communities over the long term, unblock critical wild salmon habitat, and enhance the health and function of the watershed.
Nature-based solutions
Natural defences, also known as nature-based solutions, include planting riparian buffer zones, creating wetlands, and relocating people and infrastructure out of extremely flood-prone areas. Healthy floodplains can slow the flow of water, using side channels and wetlands to store extra water.
Giving room for the river – sometimes called “managed realignment” – is an important tool in the toolbox of floodplain management. Moving dikes back from the river increases the width of the river floodplain, changing it from being narrow and channelized to broader, more natural, and eventually, a healthy complex ecosystem. Of course, in an area as compact and complex as the lower mainland, where over 350,000 people live in the floodplain, any decisions to realign dikes and relocate people out of harm’s way must include a full conversation about land use and be conducted in a thoughtful way that doesn’t overburden communities.
Left: Connected Waters Campaigner Lina Azeez checks traps during a canoe tour of the Katzie Slough in Pitt Meadows. Concerned residents raising awareness about the impacts of flood infrastructure on this waterway helped to kickstart the Connected Waters work. Credit: ©Rick Moyer. | Right: A fish-friendly sluice gate allows for the flow of water and the movement of fish. During our summer field work WW Field Crew captured a juvenile salmon at this site proving that gates like this do work in allowing fish passage and also protecting communities behind dikes from flooding. Credit: ©Meghan Rooney
Natural defences like these are an excellent long-term investment. A recent study by the International Institute for Sustainable Development found natural solutions are 50% cheaper than hard engineered infrastructure. Unlike grey infrastructure (pumps, gates, dikes), which depreciate over time, these greener alternatives appreciate and become more resilient with time. Natural defences provide numerous benefits. including the potential to sequester carbon in the long term. Wetlands can be good habitat for birds, amphibians, beavers, and turtles. They also filter water, creating good water quality for salmon. Wetlands and side channel habitats are also excellent shelter habitat for salmon during flood events.
We can also take better care of our watersheds by changing the way we log and develop our lands. In the upper watersheds, clearcut logging, on top of wildfire impacts, mountain pine beetle attacks, and more intense weather, is contributing to landslides and flooding in many areas.
In places where strengthening grey infrastructure technologies, such as pump stations and flood gates, is the only practical way to keep communities safe, there are now fish-friendly designs that allow salmon to safely pass through them.
Aerial photo during construction of a fish-friendly gate on the Lower Agassiz Slough in the District of Kent. This work opened up 7km of prime overwintering and rearing habitat for salmon and other species. The gates are designed to stay open for 11 months of the year except during extremely high-water levels such as during the Fraser River spring snow melt events. | Credit: ©Roxanna Kooistra
The District of Kent, in Agassiz, recently upgraded an old flood gate and narrow culvert with a massive culvert and a fish-friendly gate that will remain open nearly 11 months of the year, connecting seven hectares of upstream salmon habitat in the Lower Agassiz Slough to the Fraser River. The gate is designed to close when water in the Fraser River is high, during the spring snow melt for instance. This system protects the community behind the dike and allows safe access to important habitat for salmon nearly all through the year.
We are at a crossroads. The federal and provincial governments are putting hundreds of millions of dollars into Pacific salmon recovery. These investments will be wasted if they also spend billions of dollars on the same old flood control systems that continue to kill salmon and undermine floodplain resiliency.
There’s nothing like an emergency to spur action, but we must ensure it is the right kind of action. If we do this right it’s a win-win-win: we give wild salmon a boost, save taxpayer dollars, and make our communities even safer from flooding.
Before and after photo of the new fish-friendly gate constructed on the Lower Agassiz Slough. Collaboration is key in making projects like this a success. Watershed Watch and Resilient Waters supported the District of Kent in their application to the Healthy Watersheds Initiative for $700,000 to restore fish passage and better manage flood waters.
Lina Azeez is the Connected Waters campaign manager for Watershed Watch Salmon Society. She respectfully lives, works and learns on the traditional and unceded territory of the Kwikwetlem Nation. www.watershedwatch.ca/connected-waters
