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Executive Summary

Climate change in Canada is expected to bring hotter, wetter, and wilder weather, which could impact dams across the country. In the dam industry, existing dam safety and operations guidelines and regulations do not specifically address how to adapt dams to climate change. Therefore, the impact climate change may have on dams, the need to act, and the path forward to address climate changes to dams is not yet well understood.

This research sought to better understand the climate risks impacting dams in Canada; the existing standards, guidelines, and best practices that address climate change adaptation for dams; what is currently being done to address the issue; and what solutions are needed. This is done through a literature review, stakeholder interviews and a workshop, and validated by an advisory panel of industry experts.

The literature review found that major climate risks to dams include changes to the hydrologic cycle potentially impacting design loads and Inflow Design Floods (IDFs); changes to operations and maintenance to respond to different operating needs, frequencies and conditions; changes to foundations due to melting permafrost; issues with site access due to storms and extreme weather events; additional stress on water supply impacting dam operations and functionality; impacts to hydropower generation due to a less predictable hydrologic cycle; and more. The review found that guidance documents on how to adapt infrastructure to climate change are often not applicable to the dams context. Some guidance at the international level on climate adaptation for dams exists but remains high level and difficult to interpret to the watershed-specific context. Other regional guidance exists but similarly lacks detail or applicability to dams across the country.

The stakeholder engagement presented an essential perspective on the status and needs of stakeholders in the dam industry in managing climate change impacts to dams in Canada. Opportunities for research and development include increasing climate data availability and the capability of stakeholders to access and interpret it properly. Most stakeholders who had begun addressing climate risk to dams had conducted climate risk assessments to determine where a dam system is potentially vulnerable to climate change. Few actual adaptation measures or projects were reported, other than projects focused on identifying the highest climate risks. Several stakeholders had not taken steps towards assessing climate vulnerabilities or adapting where needed. Some expressed a lack of clarity on the steps to take, others lacked incentive to act.

The inconsistency in the consideration of climate risk and the potential vulnerabilities identified for dams in Canada presents a need for guidance on the steps to take towards climate adaptation. Stakeholders were interested in having processes and best practices for climate change adaptation outlined, but there were also some identified barriers. These included limitations in the availability and interpretation of climate data and limited industry experience in applying this data to assess impacts and adaptation actions for a site or watershed. The following actions were provided as a road map towards climate adaptation to address current barriers and seize opportunities for industry alignment:

• Assess and address climate change data needs for dams through research and collaboration.
• Establish best practices and prepare a guidance document for conducting climate change vulnerability and risk assessments for dams.
• Establish best practices for climate and non-climate related risk-based decision-making for dams.
• Create a process that can be used to guide adaptation decision-making through consultation with stakeholders and researchers who have worked on climate adaptation specific to dams.
• Conduct further research on the climate change related impacts to small dams and prepare a guidance document with climate adaptation considerations specific to small or lower consequence dams.

To address these opportunities, research and consultation would be needed to determine the appropriate level of detail to ensure the feasibility and robustness of guidance documents. This study concluded that climate adaptation best practices compiled in a standard or guideline would be valuable for Canadian dam owners and practitioners as it could provide knowledge of unknown risks and tools for appropriate adaptation to climate change.