Metro Vancouver recently completed a project to manage debris flows in the lower Grouse Mountain area of the Capilano watershed, which has improved safety for park users.
The Lower Grouse Mountain Debris Flow Mitigation Works project was initiated by Metro Vancouver’s Water Services Department, following a survey of the Mackay and Grouse Creeks done several years ago. The survey identified that wood and rock debris flows from the creeks could potentially reach the Grouse Mountain Resort parking lot.
A debris flow is a moving mass of loose mud, sand, soil, rock, water and air that travels — sometimes at high speeds — down a slope. Debris flows can be triggered by intense rainfall, snowmelt and other factors.
As part of the project, two large steel net fences and a large raised bank with check dams were installed above Parking Lots A and D at the base of Grouse Mountain to catch any debris reaching that area. As an additional safety measure, a small portion of Parking Lot A will be closed during winter months when there is an increased risk of debris flows.
Construction started in 2019 and is now complete, with landscape restoration scheduled for later this year. The project has successfully reduced the risk of any wood or rock debris reaching the parking lot; these increased safety measures will protect the public and Grouse Mountain Regional Park infrastructure well into the future.