Canada holds nearly 20% of the world’s freshwater supply, but that does not guarantee reliable access or infrastructure resilience. As wildfires become more frequent and intense, they are placing added strain on water systems across the country—revealing limitations in capacity, quality protection and system design.
This evolving risk landscape is prompting municipalities, planners and operators to re-evaluate how water systems are structured and maintained—not just for daily demand, but for environmental stress.
Suppressing wildfires requires large volumes of water, often drawn from the same sources that serve drinking water, sanitation and industry. In urban areas, firefighting typically relies on reservoirs, water towers and underground storage tanks connected to pressurized mains and hydrants.
This emergency use can place immediate stress on municipal systems. High-volume drawdowns during fire response can reduce water pressure, deplete reserves and interfere with routine operations like drinking water delivery, sanitation and industrial processing. In systems with aging infrastructure or limited storage capacity, the result may be noticeable service disruptions or the need to ration supply during and after a wildfire event.
In smaller or rural communities, where formal infrastructure may be limited, firefighting often relies on nearby lakes, rivers or streams. Water may be pumped directly from these natural sources, loaded into trucks at access points or drawn by helicopters during aerial suppression. While these sources offer flexibility in remote settings, their use can affect ecological health. Rapid withdrawal—especially during dry seasons—may lower water levels, disturb aquatic life and disrupt shoreline habitats. Sudden changes in temperature, turbidity or nutrient concentration can impact water quality, particularly in shallow or sensitive ecosystems.
Where surface water sources serve both emergency and potable water needs, this dual use also raises concerns around contamination risk, treatment complexity and coordination between fire operations and water utilities.
What this means for water planning: Water systems must be designed with surge capacity in mind—balancing everyday needs with potential firefighting demand. That includes expanded storage, backup pumping capacity, clear coordination protocols and source water protection measures to minimize ecological disruption.
Beyond immediate demand, wildfires disrupt natural processes that help sustain water availability. Vegetation plays a key role in regulating the water cycle—retaining rainfall, slowing runoff and supporting groundwater recharge. When forests and grasslands are burned, this natural buffering capacity is lost.
As a result, rainfall moves more quickly across the landscape, increasing erosion and reducing infiltration. Over time, this can contribute to sustained dry conditions, intensifying the cycle between drought and fire. In regions already facing seasonal scarcity, these shifts place additional pressure on both natural and engineered water systems.
What this means for water planning: Watershed restoration must be viewed as a water infrastructure strategy. Protecting and replanting vegetation in critical recharge zones helps maintain local hydrology, slow erosion and extend the reliability of supply systems in dry conditions.
After a wildfire, ash, sediment and contaminants from burned vegetation and structures can be washed into rivers, lakes and reservoirs. These pollutants may increase turbidity, introduce nutrients that encourage algal blooms and carry metals or synthetic compounds into source water.
For treatment facilities, this presents operational challenges—requiring adjustments to filtration systems, chemical dosing or source selection. In some cases, municipalities may issue boil-water advisories or seek alternate supplies until post-fire runoff subsides.
Surface water quality impacts can also disrupt aquatic ecosystems, reduce recreational access and raise long-term treatment costs.
What this means for water planning: Treatment systems must be adaptable. Utilities may need modular treatment units, mobile equipment or enhanced filtration systems capable of responding to post-fire water quality fluctuations—along with monitoring tools that provide early warning of runoff events.
Wildfire activity highlights the need for water infrastructure that can function under stress—whether from sudden emergency drawdowns or long-term ecological shifts. Designing for resilience means moving beyond historical demand patterns and building systems that can maintain service despite unpredictable events.
Key considerations include:
What this means for water planning: Resilience is now a primary design principle. Future systems must accommodate uncertainty—through flexibility, redundancy and integration with broader emergency management strategies.
As wildfires become a more regular feature of Canada’s landscape, their interaction with water infrastructure must be considered in long-term planning. Water systems are not only service utilities—they are critical resilience assets.
What does this mean for water planning? It means that wildfire risk should be explicitly factored into capital planning, infrastructure upgrades, watershed management and emergency response frameworks. A coordinated approach across agencies and sectors will be essential for maintaining reliable service in an evolving climate.