Dam Safety Review
Summary Description
Over 60% of Canadian electricity is generated by hydropower with hundreds of dams and associated structures. The evaluation and systematic review of this important infrastructure is based on best practices provided through the Dam Safety Guidelines by the Canadian Dam Association (CDA). The risk-informed approach assesses the likelihood and potential consequences of undesired events, following provincial and territorial regulations and to inspection of all aspects and involved components of a dam.
Dams are built to withstand climate-related events such as floods, snow and ice or erosion processes. In a changing climate, these vulnerabilities and the related risks are modified. The established Dam Safety Review process is an effective instrument to integrate information and data about future climate to ensure the safety and functionality of dams in light of the changing circumstances brought about by climate change.
Quantifying risks and vulnerabilities linked to climate change is challenging but related to issues already under consideration. For example, extreme floods are projected to increase in frequency and severity in many areas across Canada, which directly affect the inflow flood design. Projected shifts in precipitation pattern and flood mechanisms such as rain-on-snow events or snowmelt-driven floods will affect the estimated design flood as well as operations and maintenance. Dams located in permafrost regions can be affected by instability due to permafrost thawing. Rising temperatures can also create large ice movements. Access to infrastructure may be limited by more frequent forest fires (i.e. Hydro Quebec had an installation evacuated by workers to let firefighters do their work) (MacTavish et al. (2022), Islam et al. (2024)). Similarly, freezing rain, ice storms or extreme snowfall may more often limit the ability to access a dam or operate flow control equipment such as pulling logs. Structural stability of concrete dams might also be challenged due to the increase in total horizontal load caused by precipitations and streamflow (Ozkan et al. (2023)) or through more frequent freeze-thaw cycle related erosion.
The following sections describe the role, some method and models, as well as gaps and recommendations in dam safety review.
Role in the Electricity System
Methods and Models
Methods and models for DSR are manifold and can require many inspections following regulations (Engineers & British Columbia (2023), Natural Resources (2023)) or the practices establised at utilities. Examples include:
- field reviews
- interviews with site staff
- equipment testing
- extensive understanding of the design, construction, operation and maintenance
The Canadian Dam Association provides links to regional legislation documents for more information.
The following sections highlight some methods and models used in DSR. Among the wide variety of field expertise required for a comprehensive review (e.g. structure, geotechnical, hydrological, hydraulic, seismic, mechanical, electrical, etc.) methods presented here will focus on hydrology which is immediately affected by climate change. Other types of methods and models are briefly discussed.
The figure below summarizes decision-making challenges faced by professionals involved in dam safety review in the electricity sector in Canada. These challenges were shared during the workshops held in 2025. Q: Miro Board needs editing!! The examples illustrate the links between methods, models, the related data as well as challenges when using the methods and models detailed below.
Please refer to the climate dataset sections for guidance and availability on climate variables used in the examples below.