The municipality has been monitoring remediation efforts after a stacked rock wall on private property failed in the Rainbow subdivision recently.
It is the second wall failure at the neighbourhood, which is an ongoing construction site, and comes amid an ongoing lawsuit between a neighbour, who was injured by a falling rock close to his home, and Rainbow's developers.
"I'm concerned," said Mayor Nancy Wilhelm-Morden of last week's incident. "Whenever anything like this happens it's a matter of concern."
She highlighted the fact that the wall failed on private property. As such, it is the homeowner's responsibility.
Property owner Rod Nadeau explained that the wall, which had been approved by a geotechnical engineer, was a not a structural rock wall.
"It was a landscape feature that didn't work out very well," he said. "It was just there to hold up some top soil so we could put some trees in it and hide the rock face behind it. So it was supposed to be a stepped rock wall with a lot of landscaping in it."
The topsoil behind the wall, he explained, became very saturated with water run off from his home above, which caused some of the rocks to come down.
According to the RMOW, Nadeau was given specific remediation instructions, to be done under the supervision of a professional geotechnical engineer to confirm that hazards have been mitigated.
Nadeau confirmed that has been done. "We're not going to rebuild it, we're just going to plant it up," he added.
The municipality explained: "Certification by a geotechnical engineer is required for all subdivision related works (road construction, preliminary site grading etc.)... In addition, RMOW Building Bylaw No. 1617 requires that all retaining walls over 1.5 metres in height be designed and approved by a professional engineer. If there is a failure in a retaining wall, remediation work is done under the supervision of a professional geotechnical engineer."
Just over a year ago, in October 2011, a rock wall failed in the Baxter Creek subdivision, which borders Rainbow, after one of the rocks moved at the bottom of the wall. The wall was torn down and rebuilt.