'This is just the tip of the iceberg': 148 properties in Oliver, B.C., area under evacuation alert

"Sportsmens Bowl [Road] is completely underwater, the water has actually ripped up the concrete and made a channel down the road. The flow is immense, it's definitely impressive," local resident said.

Park Rill Dam close to spilling over and has seen unusual amounts of water in recent years

City of Kelowna crews dredging Mill Creek to remove sediment and vegetation. Across B.C.'s Interior, flood preparation is underway ahead of what could be a powerful spring thaw. (Brady Strachan/CBC)

Residents north of Oliver, B.C. have been on high alert all week due to the threat of a mudslide from a local dam.

Last week, the Regional District of Okanagan-Similkamen issued an evacuation alert for 16 properties along Sportsmens Bowl Road.

The alert grew to include 148 properties Monday night because the privately owned Park Rill Dam is close to spilling over.

"We're concerned that if more water does come in there could be an overtopping incident at the dam that may lead to its failure," Mike Noseworthy, senior regional dam safety officer for Thompson-Okanagan region, said Tuesday.

He said the dam has seen an unusual amount of water in recent years and this season especially.

"We're really not clear on how much more water is coming down, if we've reached a peak or if we'll continue to see the waters rise in this area… We've only see the lower elevations, mid-elevation snowpack retreat at this point so there's still a lot of snow left to come," he told Radio West's Sarah Penton.

The Regional District of Okanagan-Similkamen issued an evacuation alert for 148 properties in the area shown here. (Regional District of Okanagan-Similkamen)

The dam is quite old, according to Noseworthy, who said it was inspected last year and deficiencies were identified that were meant to be repaired this year.

"We're looking at a fair amount of water being released and there's quite a large drop down to… where all the residents are located through a gully that has erodible soil," he said.

"Our concern is not just a flooding effect but also it could trigger a debris flood or flow that would cause even more damage."

The district issued a release to residents that said Highway 97 would remain open and no residents would be asked to leave their homes at this time but conditions could change.

"Affected residents will be given as much advance notice as possible prior to road closure or evacuation; however, residents may receive limited notice due to changing conditions," the release said.

Local business owner Nick Durisek runs the Howling Moon Cider House on Highway 97 and has witnessed the impact of the flooding so far.

"Sportsmens Bowl [Road] is completely underwater, the water has actually ripped up the concrete and made a channel down the road. The flow is immense, it's definitely impressive," Durisek said.

Durisek isn't too concerned about the mudslide threat but said that flooding around this time of year is common and is thinking about his orchard of apple trees on the two-hectare parcel of land he's on.

"We have a dyke… that goes down our property so a lot of the water is able to get away but rising water all around here is definitely a problem and a concern," he said.

"This is just the tip of the iceberg here. It can get pretty bad."

The district says a dam and culvert on Secrest Road could release water and debris for several kilometres.

The properties affected by the expanded alert are on: Covert Place, Highway 97, Horsetail Road, Island Road, Knight Road, Pampas Grass Way, Park Rill Road, River Road, Secrest Hill Road, Sitka Road, Sportsmens Bowl Road, Test Orchard Road and Wheatgrass Road.

A full list of the affected properties can be found on the district's website.

The district says a separate evacuation alert in the Green Lake area remains in effect.

With files from Radio West, Liam Britten