January 18, 2018
MOUNT CURRIE LANDSLIDE RISK ASSESSMENT COMPLETE:
Determines low probability of a large impact event; community information meetings scheduled for January 24th and 25th
Pemberton, BC – Local Officials have received the results of the Mount Currie Landslide Risk Assessment (“the Assessment”), conducted by BGC Engineering Inc. (BGC). BGC was engaged to determine landslide and associated flood risk from the north face of Mount Currie Mountain including risk to life, buildings, critical facilities, business activities, power and communication lines. The Assessment was prompted by an increase in observed small rockfall events during the summers of 2015 and 2016, which raised concerns about the potential risk to the communities below the north face of Mount Currie. The completed Assessment has confirmed areas of instability that could result in small rockfall events and rare but large-scale rock slope failures.
Elected Officials from Lil’wat Nation, SLRD and Village of Pemberton (Village) met today to review the report with BGC engineers and have agreed to continue joint advocacy efforts to secure funding for further studies and monitoring systems, as recommended by the Assessment. On a staff level, Emergency Program Managers from all three jurisdictions will integrate this new information into existing Emergency Management plans.
According to the BGC analysis, up to nineteen potential rock avalanche source zones exist, with four being identified as having high hazard potential. Two of those four zones, known as Scenario 1 and 2 (see enclosed map) were identified as having the potential for rock avalanches large enough to travel north of the Green and/or Lillooet Rivers. In these two scenarios, the rockfalls are predicted to travel over 100km/hour and involve volumes up to approximately 8 million cubic metres of material.
Associated damming of the Green and Lillooet Rivers was also assessed; approximately 160 buildings within the study area were identified as having a higher vulnerability (greater than 1m flow depth above the estimated first floor elevation), should Scenario 2 occur.
Geoscientists have calculated that the annual probability of the modeled rock avalanche of Scenario 1 is approximately a 0.02% chance of occurrence in any given year, while the annual probability of the modeled rock avalanche of Scenario 2 is a 0.009% chance of occurrence in any given year, under current conditions and current weathering and erosion rates. For comparison, the probability is similar to the estimated probability of large debris flows from Mount Meager (Friele et al. 2008).
Mount Currie’s stability is believed to be influenced, in part, by the assumed existence of permafrost. With climate change, the report concludes that permafrost will degrade and the ice presumed to be present will melt. This would imply a higher frequency and possibly higher magnitude of rock slope failures in the future.
Due to Mount Currie’s size and the number of source zones for rock avalanches, the Assessment states that engineered mitigation options are not practical. As a result, BGC has recommended monitoring as the most practical and cost-effective approach to risk management. The Assessment also recommends that land use be restricted in part or all of the areas modeled for rock avalanches, as any increase in development density would increase the population at risk.
The full report is available for download from the following websites:
Community information sessions will be held in Pemberton and Lil’wat Nation:
- Wednesday, January 24th from 6:30-8:30pm at the Pemberton & District Community Centre, and
- Thursday, January 25th from 6:30-8:30pm at the Ull’us Community Complex.
Community members are encouraged to attend either meeting. Each information session will begin with a presentation of the Assessment findings by BGC engineers, who will also be available to answer questions. To ensure that as many questions as possible can be answered at these sessions, community members are encouraged to review the Assessment in advance and submit their questions prior to the community information meetings to one of the community contacts noted below:
- Lil’wat Nation: Sylvia Dan (Sylvia.firstname.lastname@example.org)
- SLRD: Sarah Morgan (email@example.com)
- Village of Pemberton: Jill Brooksbank (firstname.lastname@example.org).
The Mount Currie Landslide Risk Assessment was funded provincially through Emergency Management BC (EMBC) and overseen by a steering committee composed of representatives from the SLRD, Village, Lil’wat Nation, the Ministry of Forests Lands and Natural Resource Operations and Rural Development (MFLNRORD) and EMBC.
“We have existed on these lands, with the very potential for natural disaster impacts, all our lives in this valley. We live between two rivers that are annually very active in their natural high and low flows. The mountains are no different in their actions and have been very active in the recent years. I feel that we are responsible to our community members to communicate all information that pertains to their safety and wellbeing, which includes the steps of inquiry and applications of professional advice that we have undertaken collaboratively with our neighboring communities.” – Dean Nelson, Political Chief, Líl̓wat Nation
“This Assessment has given us a more complete understanding of the risks related to rock avalanches on Mount Currie, and it will help all of our organizations with future land use and emergency management planning. We are grateful to the Province of BC for making this study possible, and we look forward to working with our local, provincial and federal partners as we explore further studies and monitoring options to keep our communities safe.” – Jack Crompton, Board Chair, Squamish-Lillooet Regional District
“We understand this new information is concerning, however we now have a better understanding of the potential risks and we can plan accordingly. The Village will integrate this new information info existing emergency management plans, and consider this information during our Zoning Bylaw update. The Village, with our partners, will continue joint advocacy efforts to secure funding for monitoring systems and further studies. As we learn more about the dynamic characteristics of Mount Currie, we will continue to share this information with our communities.” – Mike Richman, Mayor, Village of Pemberton
About Mount Currie Mountain
Located within Lil’wat Traditional Territory, Mount Currie Mountain, also known as Ts’zil in Ucwalmicwts, is a spectacular 2,591 m (8,501 ft.) peak overlooking the Pemberton Valley. Mount Currie is Crown Land that falls within Electoral Area C of the Squamish-Lillooet Regional District and situated between Lil’wat Nation and the Village of Pemberton. Mount Currie is the northernmost summit of the Garibaldi Ranges in southwestern British Columbia.
About the Squamish-Lillooet Regional District (SLRD) | www.slrd.bc.ca
Located in southwestern BC, the Squamish-Lillooet Regional District (SLRD) is a local government federation consisting of four member municipalities (the District of Lillooet, the District of Squamish, the Village of Pemberton and the Resort Municipality of Whistler) and four unincorporated, rural electoral areas (A, B, C, and D). Headquartered in Pemberton, which is the approximate geographic centre of the region, the SLRD delivers a wide range of local, regional and sub-regional services to approximately 43,000 residents.
About Lil’wat Nation | www.lilwat.ca
The majority of Líl̓wat Nation citizens live near beautiful Mount Currie, British Columbia. The community is home to the majority of the nation’s more than 2,000 members. The people of the Líl̓wat Nation are engaged in all economic sectors while continuing to celebrate, and engage in, traditional ways. Fishing, hunting and harvesting indigenous plants for food and medicine are among the cultural practices that have endured since time immemorial. The Líl̓wat Nation’s Traditional Territory boundaries extend south to Rubble Creek, north to Gates Lake, east to the Upper Stein Valley and west to the coastal inlets of the Pacific Ocean. This 791,131 ha of land occupies a transition zone that goes from temperate coastal environment to the drier interior of British Columbia.
About the Village of Pemberton | www.pemberton.ca
Pemberton is one of the most desirable communities in BC and home to family farms, fresh outdoor adventures and stunning vistas. With over 2,400 residents and just 30 km from Whistler, Pemberton prides itself on its creative and collaborative approach with the business community, local volunteer groups, neighbouring communities and key business and tourism partners such as Tourism Pemberton and the Pemberton & District Chamber of Commerce. Pemberton’s mild winters, warm summers and unique pioneer heritage provide an ideal place to enjoy arts, culture, history, recreation, dining, shopping and comfortable lodging.
Telephone: (604) 894-6115 ext. 2223
Communications and Grants Coordinator
Squamish-Lillooet Regional District
Telephone: (604) 894-6371 ext. 239
Sr. Communications and Grants Coordinator
Village of Pemberton
Telephone: (604) 894-6135 ext. 230