This year’s freshet, although kinder than other years, did see four main slides impact roads in the central Cariboo, said Todd Hubner, district manager with the Ministry of Transportation and Infrastructure during an update to the Cariboo Regional District.
The four areas include the Highway 20 slide, the Dog Creek Road slide, Northern Ranches just off the Tzenzaicut Lake Road on the West Fraser and another area east in Beaver Valley.
Hubner said the Dog Creek Road/Shaw slide started in 2014.
Crews did some work to get drivers through the winter this past year.
“The short-term fix was to tear the pavement off, and go back in and resurface it over the short term,” Hubner said.
“We think this area may be in fact be part of a larger slide complex associated with the Highway 20 slide below the old college site, which started moving last year.”
Hubner said the long-term goal is to put instrumentation in the ground to better understand what is happening in both areas.
In the meantime, the ministry is hopeful the work completed last month will last for a year or so.
The Tzenzaicut Lake Road on the West Fraser slide area received a heavy amount of water.
“We are finding that many of our drainage infrastructure components are severely undersized for the intensity and frequency of the storms we are getting,” Hubner said.
“We are looking at a whole new crossing, perhaps bridge it or put in some form of an imbedded pipe, for next year.”
In the meantime, access to the road has been “band-aided” temporarily.
The washout at the Beaver Valley Road has been recurring for several years, he said.
“We’ve got a series of small culverts passing the water underneath, but what tends to happen because we have a large alluvial fan area there, we see a lot of deposition during freshet and post freshet.”
In other words, a lot of water is moving there, and when it builds up it floods all the infrastructure.
Last summer the ministry did some hydraulic work and in the fall started putting a plan in place and began to reconstruct a new wide meandering channel about 300 metres in length.
“It’s going to slow the water down,” Hubner said of the new channel, noting potentially there will be a crossing there, most likely a bridge structure, hopefully in two years.
The ministry has purchased property at the site to do the work and has been working closer with the adjacent landlord.
Typically the road has been closed for two weeks on average in the last five years because of the amount of water that accumulates there, Hubner said.