Bridal Falls Landslide Hazard Assessment

In our long term planning for growth and development of Bridal Falls, the FVRD hired expert engineers and geoscientists to provide advice on hazards in the area. These experts have identified a very low risk rock avalanche hazard from the slopes above Bridal Veil Falls Provincial Park. Nothing in the engineering reports indicates that it is not safe to live, work, or recreate in the Bridal Falls area. Day to day living and construction such as building a house or an addition can continue as normal in Bridal Falls. It does mean that the FVRD and provincial approving officers may direct new growth and density including subdivision to areas outside the rock avalanche hazard area.

What area may be affected for new growth?

 

  1. What is a rock avalanche?

    It is likely you have seen debris flow (mud, branches, small rocks) in this area, which is typically caused by excessive rainfall. This kind of activity can occur on virtually any slope in the province.

    In contrast, rock avalanches are very large, fast moving landslides involving large fragments of broken rock. They are infrequent, rare occurrences that can cause a lot of damage. The 1965 Hope Slide along Highway 3 is an example of a rock avalanche in our region. Most rock avalanches are so large we cannot do anything to prevent them from occuring.

  2. How likely will a rock avalanche occur?

    Expert geoscientists have calculated the chance of rock avalanche in any given year in Bridal Falls to be a probability of 1 in 10,000 years (0.01%). In other words, 99.99% of the time, a rock avalanche will not occur. To put this into perspective, there is a 22% chance that the Fraser River will experience a catastrophic flood in the next 50 years. And, some experts predict that there is a 1 in 4 chance that the Lower Mainland will have a major earthquake within the next 50 years. In this case, engineers have calculated that there is a 99.5% chance that a rock avalanche will not occur in the next 500 years.

    Unfortunately, there is nothing we can do to protect our properties from the effects of a rock avalanche. With earthquakes, there is technology that can reinforce buildings and reduce the amount of damage. With floods, you can build above flood levels or construct barriers and dams to protect your property.

  3. Does this mean our property is unsafe to live in?

    Nothing in the engineering reports indicates that it is unsafe for you to live in your home or operate your business. Day to day life is no different today than it was yesterday. Residents and businesses are not forced to move and building can still continue. If you want to build a new house or an addition to your property, the same zoning and building regulations are in place. You will simply fill out the same applications with the FVRD that you always have. Now that the FVRD and the provincial approving officer better understand this potential hazard, we can plan new growth areas for the future.

  4. Can I still subdivide my property?

    Provincial Approving Officers have jurisdiction for subdivisions in regional districts. Every application for subdivision is reviewed objectively and independently. The results of the engineering studies have been provided to the provincial approving officer for their consideration in approving future subdivisions. For further information, please visit http://www.th.gov.bc.ca/DA/L3_min_trans.asp.