Canada is a country with extensive experience in avalanche risk management. This expertise is reflected in the operations that are activated every winter on the Trans Canada Highway or Highway 1. This highway, which traverses significant mountainous areas, experiences a high potential for snow avalanches, far exceeding the roads affected by avalanches in the Pyrenees that Arantec is familiar with.
Why is Highway 1 significant when it comes to avalanche risk management?
The Trans Canada Highway, spanning approximately 7,000 km, crosses the country from east to west. Along its route, it passes through major topographical features such as the Rocky Mountains and the mountains of British Columbia. These areas, accounting for about 40 km of the highway, are prone to significant snow avalanches during the winter. The highest-risk points due to their altitude include Kicking Horse Pass, Three Valley Gap, and Rogers Pass. Given the high traffic volume on this highway, effective avalanche risk management is crucial. The responsibility for executing this task falls on Parks Canada, which has been conducting the world’s largest avalanche control operation since 1960.
To illustrate the complexity of this work, let’s focus on the section of Rogers Pass, where the highway shares its route with the Canadian Pacific Railway. In this region, snowfall can reach up to 15 meters per season, with approximately 130 avalanche paths capable of generating avalanches that can disrupt communications.
A bit of history
The railroad track in Rogers Pass was completed in 1885. At that time, the only defense system against avalanches consisted of some inadequate and insufficient wooden snow sheds. As a result, over the course of 80 years, 200 people lost their lives due to snow avalanches.
The most significant tragedy occurred in 1910 when an avalanche intercepted the railway track. While a group of workers was clearing the track, a second avalanche hit the area, resulting in 62 deaths.
The passage through Rogers Pass was abandoned until the 1960s due to the magnitude of the avalanche danger, human losses, and high maintenance costs of the road. From that point onwards, studies resumed, an avalanche forecasting program was established, new defense structures were built, and artificial triggering systems were implemented. These measures allowed for the reopening of the communication route.
How is avalanche risk management carried out today?
Currently, various teams collaborate in the avalanche control operation to ensure public safety.
Firstly, the avalanche forecasters from Parks Canada monitor meteorological conditions and the evolution of the snowpack. Based on this information, decisions are made to mitigate the risk through the use of explosives or road closures. Secondly, personnel from the military, who temporarily reside in the area, are responsible for detonating explosives, triggering avalanches that eliminate or reduce the danger. The military has 18 locations where they conduct detonations using mobile 105 mm Howitzer cannons. Thirdly, road maintenance personnel clean the highway to reopen it to the public as soon as possible .Through the collaboration of these teams, the goal is to effectively manage avalanche risk and ensure public safety in the area.
The highway also features protective structures, including 7 snow sheds and avalanche fences in the avalanche-prone areas, as well as 2 tunnels that protect the railway track. The combination of these measures allows for the road to remain open and safe on most days during winter.
Improvements made in recent years
In recent years, several improvements have been implemented to minimize road closures and enhance worker safety. Some of these initiatives include:
- Installation of an avalanche detection network: Real-time information on avalanche activity is collected through the following components:
- Infrasound avalanche activity detection systems placed along the valley floor near avalanche runout zones.
- Radars positioned on the opposite slope of the monitored avalanche areas to detect the initiation of avalanche cycles. When an avalanche is detected, a camera is activated, capturing instant images.
- A web platform processes all the information, displaying it on a map and automatically notifying forecasters of any updates in the conditions.
- Implementation of Remote Avalanche Control Systems (RACS) in the starting zones: This solution allows for remote detonation of explosives under any weather conditions. Avalanche control towers have been installed to significantly reduce the triggering time from 1 hour to 5 minutes.
- Installation of additional avalanche fences: More meters of avalanche fencing have been added to enhance protection.
- Rehabilitation of existing static defense systems: Dams or berms designed to trap or divert avalanche debris have been repaired. Additional earth mounds have been constructed to prevent avalanches from reaching the road.
- Structural repairs of snow sheds along the highway.
Conclusion
Canada is a leading country in snow avalanche risk management. Although Rogers Pass is located at just over 1200 meters above sea level, the climate in the region is extreme, with heavy snowfall that hinders transportation. At Arantec, we are accustomed to working in supervising snow avalanche risk in places like the Pyrenees. The conditions between the two locations differ significantly, but we always strive to learn from the best.
Sources consulted:
VG, Schleiss, 1989. Rogers Pass Snow Avalanche Control – Summary. Glacier National Park, British Columbia, Canada
