An apparent rockslide has taken place along a closed section of Stanley Park's seawall.
Vancouver's Board of Parks and Recreation said large pieces of sandstone were found close to Siwash Rock on Tuesday, Feb. 18.
Crews believe "significant slope instability," as a result of fluctuating temperatures this past week, caused the rocks to plummet to the ground.
"These rocks detached from the slopes above as a result of the recent freeze-thaw conditions we've observed across the city," said Andrew Seeton, senior engineer with the Vancouver Board of Parks and Recreation, in a statement to V.I.A.
"During the recent sub-zero temperatures, water that got in behind the joints of the rocks froze, then expanded. The subsequent increased temperatures meant that the ice melted, further loosening the rocks and leading to some slope instability in this area."
Officials have now extended the closure of the seawall between Third Beach and Prospect Point.
That portion of the seawall has been cordoned off "until further notice" since Feb. 7, which was prompted by ice build-up along overhanging slopes.
Exposed to the elements
Seeton explained the seawall by Siwash Rock is vulnerable to severe weather conditions.
He said park crews actively monitor Vancouver's forecast to determine if public safety is at risk and if a closure is necessary.
This can include:
- High rainfall
- Debris slides onto the seawall pathway
- Freezing temperatures
- Snow and ice on the cliff faces and seawall pathway
- Thawing conditions
- Allows fractured rock segments to fall onto the pathway
- High winds
- Topple trees or other vegetation onto the pathway
- Coastal storms with storm surge
- Waves overtopping, damaging, or washing out portions of the seawall pathway
"The Park Board's annual program of slope stabilization work removes existing loose material and helps to mitigate against the need to close the seawall," Seeton noted.
"However, with public safety being a primary concern, we do occasionally need to close this section to the public in the event of severe weather conditions or when the slopes are at risk."
Detour through the forest
Pedestrians, cyclists and other visitors continue to be redirected into the forest along Avison Trail, Prospect Point Trail, Bridle Path, and Rawlings Trail (see map below).
Seeton said the Third Beach-Prospect Point stretch of the seawall will stay closed until cleanup and repair work is complete.
"We'd like to remind the public to observe all site signage, avoid accessing this section of the seawall at all times, and keep an eye on Park Board channels for further updates."
With a file from Brendan Kergin. Video edited by Alanna Kelly
