A rockslide at Gallagher Lake recently damaged a section of irrigation flume.
The Town of Oliver has a repair job on its hands as it races to fix a damaged flume before irrigation season begins.
Director of Operations Shawn Goodsell confirmed that a recent rockslide at Gallagher Lake damaged some pipe.
He noted that one section shifted and pulled away from another pipe by six inches, while a section collapsed by approximately 24 inches. There were also noticeable cracks and damages from the force of the landslide, revealing some of the steel meshing in the pipe.
Gallagher Lake resident Harold Carlson reported the slide on January 25, saying he heard the big rumble at around 6 am.
Carlson showed the Chronicle pieces of ice that strangely ended up on his lawn after the rock fall. He surmised that the impact of the slide caused a mini-tsunami on the lake, which broke the ice and propelled chunks onto his lawn.
Neighbour Dan Atkinson pointed out some large rocks that flew over his house and created divots in his lawn. In fact, one rock buried itself nearly a foot into the grass. How the rocks ended up there from such a distance is anyone’s guess.
Carlson estimated the distance at 300 feet.
At a recent council meeting, Goodsell said the water level was down in the flume, so he suggested putting a camera in there to assess the damage.
The Town’s engineering consultant and a geotechnical engineer from Golder & Associates were on site last week to look at the potential of this happening again.
“It sounds like there is always potential for rock to fall at this location because of freeze/thaw cycles,” Goodsell said.
He noted that approximately 100 cubic metres of rock fell on January 27.
To be safe enough to repair, Goodsell said they need a period of time when the temperature is over 0 Celsius, with no rain.
Staff are currently sourcing pipe to replace the broken section, which could be between 20 to 30 metres.
Goodsell said this isn’t easy to replace because of the size of the reinforced concrete pipe, which is 1,950 millimetres (76-plus inches) and not standard. The company the Town used in 1997 to make the pipe is looking into the request.
Goodsell said they also need to source a contractor to install the pipe, and they want to “camera” the siphon from the other end.
“We have a short window before irrigation season starts in early April,” he said, noting the weather will have to cooperate.
The other time factor is getting all the approvals and having the pipe made in time because it needs to cure for weeks, Goodsell pointed out.
Repair costs have not yet been determined.
