Squamish-Lillooet Regional District Geohazard Risk Prioritization Report
From 2018 to 2020, Squamish Lillooet Regional District (SLRD, the District) undertook a regional district-wide geohazard risk assessment that assessed flood, steep creek (debris flood and debris flow), and non-eruptive volcanic hazards (lahars). From 2021 to 2023, the SLRD engaged BGC Engineering Inc. to update the original study to address two key recommendations: understanding how wildfires could affect steep creek risk compared to existing conditions (i.e., a baseline risk assessment scenario) and resolving under-reported hazard exposure on First Nations reserves caused by gaps in asset data. This assessment incorporates revised methods and expands on the initial steep creek hazard inventory. This assessment supersedes both the report and the results of the previous study.
This geohazard risk assessment aims to support decisions that prevent or reduce injury or loss of life, environmental damage, and economic loss due to geohazard events. Completion of this study is a step towards this goal. The study encompasses four electoral areas, eleven First Nations, and four municipal governments.
This work was funded by Public Safety Canada's Natural Disaster Mitigation Program.
The Squamish-Lillooet Regional District (SLRD) is located in a geologically dynamic environment; mountainous, volcanic, and with many rivers and steep creeks. The objective of this report is to characterize and prioritize flood, steep creek (debris and non-debris flow) and non-eruptive volcanic geohazards in the SLRD that might impact developed properties. This provides a comprehensive overview of the geohazard risks in the region that may impact people, property and critical infrastructure.
The cost of the report was $550,000, which was funded through a grant from the National Disaster Mitigation Program
BGC Engineering Inc. was commissioned to undertake this work.
The mountainous and volcanic terrain of the SLRD creates a number of geohazards and some of these are increasing with the changing climate. While there have been several hazard reports completed in relation to single geohazard locations, there has never been one consolidated report completed for the entire geographical area of the SLRD.
The report considers the following geohazards:
flood,
steep creek (debris flood and debris flow), and
non-eruptive volcanic geohazards (lahars)
In total, BGC identified and prioritized 2058 geohazard areas encompassing over 1615 km2 (10%) of the SLRD, including 1,845 clear-water floods, 201 steep creeks, and 12 volcanic geohazards. The report focused on areas where people will be impacted by geohazards either through where they live or impacts on critical infrastructure such as utilities, road and rail corridors. As large areas of the SLRD are uninhabited, the 10% of the SLRD studied represents the area of assessed impact on people and built infrastructure.
The report’s comprehensive recommendations aim to address data gaps, further geohazard assessments, long-term geohazard risk management, geohazard monitoring, policy integration, information management, training, and stakeholder communication.
Geohazard events occur frequently in uninhabited areas, have occurred in and near populated areas, and will occur in the future. The likelihood of an event occurring at any specific location depends on the characteristics of the specific geohazard at that location. A number of studies are available on the SLRD website of geohazards at specific locations including landslide and flood risk hazards.
The report’s recommendations are comprehensive and aim to address data gaps, further geohazard assessments, long-term geohazard risk management, geohazard monitoring, policy integration, information management and training and stakeholder communication. The full list of recommendations is included in the report.
Yes, climate change is expected to increase the risk of geohazard events occurring. Increasing temperatures, longer dry periods, more precipitation falling as rain rather than snow, and increased numbers of torrential rain events will all contribute to an increased risk of damaging geohazard events.
Emergency preparedness is a shared responsibility between local governments and residents. All property owners and residents should:
Review the information provided by their local government.
Contact their local authority for building permit advice specific to their situation if planning to build or renovate property.
Contact their local authority emergency program staff with any additional questions regarding this report.
Sign up for the SLRD emergency alert systems to be notified directly of emergencies or advisories. www.slrd.bc.ca/SLRDAlert
Sign up for the emergency alert system in your community.
Follow the SLRD (@TheSLRD) and your community on social media.
Yes. This report covers all areas within the geographical boundaries of the SLRD, including the four member municipalities (District of Lillooet, Village of Pemberton, Resort Municipality of Whistler and District of Squamish) and First Nations.
The SLRD will be considering how the report may be integrated with planning and policy, including official community plans, regional growth strategies and disaster risk reduction measures.
The full report is available on this page noted above.
