The tension crack that was discovered Thursday above the river valley trail resulted in a slide after Saturday's intense hail and rain storm.

The tension crack that was discovered Thursday above the river valley trail resulted in a slide after Saturday's intense hail and rain storm.

Updated: large tension crack gives way and slides at the River Valley

The large tension crack along the top of the River Valley in Williams Lake discovered Thursday resulted in a slide Saturday.

 

The large tension crack along the top of the river valley in Williams Lake that was discovered Thursday resulted in a slide Saturday after a torrential hail and rain storm hit the city.

Crews have been busy moving debris from the valley bottom away from the gully below since Sunday morning.

The city did not respond to our request for an update by press time.

Original story:

Mother Nature has released a large tension crack along the top of the River Valley in Williams Lake that is causing a headache.

It was first was discovered Thursday.

“A big tension crack has opened and it’s getting bigger,” said the city’s CAO Geoff Goodall Friday. The crack runs about 100 metres from the outfall line at the landfill over to the back end of the abandoned Jack Pine site on Frizzi Road.

“It’s because of the super wet conditions we’ve had and runoff generated from that across the back of that abandoned site,” Goodall said.

City staff first noticed a small slide slide went into the gully at the bottom of the river valley. After trying to determine what had happened, they decided to look up top at the Jack Pine site and that’s when they discovered the tension crack.

The property is vacant and presently being managed by receivership so no one had been physically maintaining it.

“If in reality the runoff had been controlled from the back of the lot, this likely would never have happened,” Goodall said of the tension crack.

Rain falling out of the sky is not so bad, what’s bad is when water falls onto a site, runs and congregates together, and then goes over the bank, he added.

On Thursday a temporary road was built so crews could move a hydro pole back because it’s the high voltage hydro used to operate the sewer lagoon system below.

“We don’t want to lose it so as a precautionary measure we moved a generator down there so we can run the entire system from the generator, and then we’ll move the hydro pole back in place,” Goodall said.

The city will also assess if there is any other way to get power down there, he added.

Relieved the sun is shining again, Goodall said that “no rain” is a good thing.

“The geotechnical engineer indicated to us he felt if we could keep the water out of the tension crack that piece might not fall off.”

On Friday an engineer was at the site determining whether a diversion could be installed at the Jack Pine property to ensure if there is more rain that the water does not build up again.

“Our challenge is once you divert it you’ve got to get rid of it,” Goodall said. “You can’t let it pool up because if for some reason it opened and there was a big release of water over the end, holy it would make it even worse.”

In April 2012 there was a slide nearby that destroyed a large section of the treatment water outfall and a storm outfall pipe.

 

Williams Lake Tribune