Wahid Bitar

Fire meets water: Assessing wildfire risks to water systems and strategies for resilience

Wildfires are increasing in frequency, severity, and spatial extent, driven by climate change, land management practices, and expanding development in the wildland–urban interface. While their immediate impacts on landscapes and air quality are easily visible, their effects on water systems are less apparent. Water systems are a critical lifeline, sustaining public health, economic productivity, and societal well-being. Wildfires disrupt these systems along the source-to-tap continuum, creating risks that are complex, cascading, and poorly captured in existing water planning and management strategies.

This dissertation examines how wildfires systemically impact water systems and how resilience can be enhanced across technical, environmental, governance, economic, and social domains. It draws on a critical review of wildfire–water literature alongside semi-structured interviews with sixteen experts from utilities, government agencies, and academia. Reflexive thematic analysis was employed to integrate insights across these data sources, resulting in the development of a systems-based guiding resilience framework.

Findings demonstrate that wildfire impacts emerge through interdependent cascades: watershed degradation triggers treatment challenges, operational breakdowns trigger distribution-network contamination, and governance gaps hinder effective response and recovery. The study highlights that distribution network failures, particularly chemical contamination following recent North American fires, represent a critical yet underexplored vulnerability.

This dissertation provides one of the first integrated, source-to-tap analyses of wildfire impacts on water systems, empirically validates overlooked risks through expert interviews, and proposes a novel resilience framework that extends existing tools and aligns interventions with absorptive, adaptive, and transformative capacities. Key recommendations include addressing regulatory gaps, improving inter-agency coordination, establishing financial mechanisms to support small systems, and embedding community engagement into emergency planning.

Limitations include the regional concentration of interviewees and the absence of quantitative modelling. Future studies should incorporate cross-regional comparisons, integrate quantitative systems modelling to complement qualitative insights, and examine the equity dimensions of wildfire–water risks, particularly for marginalised and rural communities.