Peter Ross, an ocean pollution expert at the Raincoast Conservation Foundation, vividly remembers the chaos brought by the 2021 floods in BC. As floodwaters surged through the Fraser Valley, he sensed a looming disaster. “It smelled like death, manure, and sewage,” Ross recalled. Rivers and ditches overflowed, carrying pollutants from fields and factories into communities.
Once the water receded, Ross and his team tested it for 379 harmful substances, including pharmaceuticals, heavy metals, and pesticides. The results were alarming. The contamination levels raised serious red flags about the safety of the water.
As climate change worsens, experts warn that such catastrophic flooding could become even more frequent and damaging. A recent report from the UN Environment Agency highlighted the potential for these mega-floods to spread dangerous chemicals, including those banned years ago due to their toxicity. Markus Brinkmann, a toxicologist at the University of Saskatchewan and co-author of the report, noted, “We’ve made progress in chemical regulation. But contamination risks remain.”
Many sites worldwide are still tainted with these banned substances, often buried deep in the ground. Flooding can disturb these chemicals, releasing them into water systems and posing health risks to communities.
Climate change, largely fueled by fossil fuel consumption, is expected to increase heavy rainfall and flood frequency. Poor management of land and water can worsen the situation. Without proactive measures, flood damage is projected to rise dramatically. From 2019 to 2023, floods caused average insured losses of around $800 million annually in Canada. Insured losses only represent a fraction of the actual damage, with people facing double the cost in uninsured losses.
The consequences of toxic chemicals in floodwaters can amplify these impacts. In the U.S., nearly 60% of the country’s contaminated superfund sites are in flood-prone areas. For instance, during Hurricane Harvey in 2017, floods swept over three tons of mercury into Galveston Bay, severely harming marine life.
To mitigate these risks, experts suggest identifying and monitoring contaminated sites before floods occur. Strategies like guiding floodwaters away from these areas or employing bioremediation techniques to clean up toxic substances can help. Building green infrastructure and establishing buffer zones that can absorb floodwaters are also vital. Ross emphasized the importance of riparian buffers, which help protect water sources. The lack of such buffers in the Fraser Valley worsened the flood’s impact in 2021.
Ultimately, pollution from human activities will inevitably find its way into waterways, threatening ecosystems and human health. The need for awareness and action is urgent, as these risks grow in a changing climate. For more insights into flood-related impacts and strategies, you can explore the UN Environment Agency’s report here.
