Forests & Floods

By Community Forests International, Posted on June 15, 2021

Community Forests International’s new report, Forests and Floods: Natural Infrastructure for a Green Recovery, highlights the important role that forests could play in reducing flood-risk in New Brunswick and similarly impacted regions in Canada. The report is part of a larger organization initiative—and a wider movement in the sector—to establish a clear economic case for protecting forests for the ecosystem services they provide to nearby communities.

The necessity for transformational investments in Canada’s COVID-19 response today runs parallel to the need for investment in climate change adaptation and green growth. Extreme weather linked to climate change continues to intensify — creating physical shocks that threaten the country’s social and economic stability. For Canada, investing in the vital natural infrastructure presents opportunities to contribute to green economic recovery from the pandemic while simultaneously increasing long-term climate resilience and disaster risk reduction.

Research Findings

  • A hydrologic study was conducted on 350 acres of mature Acadian forest along the Canaan River, which drains into the Wolastoq (Saint John) River Watershed.
  • The research found that for a 1:100-year storm event, where climate change increases rainfall intensity by 20%, built infrastructure in the form of catchment ponds would need to exceed 25,900 cubic meters to replace the peak flow attenuation services of the forest in the study area alone.
  • The cost of these catchment ponds would exceed $1,000,000.
  • This cost of replacing the flood mitigation services provided by the property far outweighs the cost of the gross value of the timber, which is estimated at $285,000.

The business case for forest infrastructure solutions

During heavy rainfall, forests act like sponges by storing water within the ecosystem and releasing it slowly into streams and rivers. A recent analysis by the Municipal Natural Assets Initiative (MNAI) indicated a flood attenuation replacement value of riparian forest (in other words, what it would cost to achieve the same flood attenuation with artificial infrastructure) approaching $30,250 per hectare. Compare this to the $1,000 per hectare top level fair market value based on forest harvest revenues alone — and the financial case for exploring forests as natural infrastructure solutions couldn’t be stronger.

Forests: our greatest climate solution

Catastrophic losses from extreme weather events have escalated in Canada over the past decade. According to the Insurance Bureau of Canada, average losses exceeded $1.8 billion between 2009 and 2017. Nearly 10% of Canadians live in areas at high risk of flooding, making it one of the most significant climate change-related threats to the country. In addition to its economic impacts, flooding has long-lasting, negative impacts on the social and mental health of those affected.

“Healthy forests provide essential water purification and flood mitigation services by slowing and filtering snow-melt and rain run-off. Forests can protect us from extreme weather events, but we have to protect them first.”
– Megan de Graaf, Forests Program Director

Forests show great promise for acting as natural infrastructure to mitigate flood damage. In the last 25 years, however, more than a third of the forest in New Brunswick alone has been cut, leaving it patchy and young, which has caused a decline in the local climate change resiliency and ecosystem services. The shift away from business-as-usual forest management must be prioritized in the Acadian forest if we hope to realize the enormous potential our forests have for flood risk mitigation.

Canada is at a crossroads

“This project highlights how forests could also contribute to local climate resilience—it shows how forests support communities by directly protecting them against the impacts of climate change.”
– Daimen Hardie, Executive Director

The COVID-19 Task Force For Resilient Recovery emphasized that a post-pandemic economic recovery must prioritize investing in the nature that protects and sustains us all. We cannot wait to move towards a just and green economy any longer.

Canada has an unprecedented opportunity to invest in the rapid transition to a low-carbon economy through natural systems and forests that benefit us all.

Keep Reading

Download the full Forests & Floods Report here.


This research was funded by Intact Financial. We gratefully also acknowledge support from the Intact Centre on Climate Adaptation at the University of Waterloo, as well as valuable insights and research provided by Dr. Charles Bourque and Antóin O’Sullivan from the University of New Brunswick, and Simon Mitchell from WWF-Canada.