Central Okanagan  

Does large snow pack = flood risk?

Some areas of the Okanagan have already experienced some localized flooding due to last weekend's unseasonably warm temperatures.

According to the head of the River Forecast Centre in Victoria an above normal snow pack on Okanagan hills and mountains could mean an increased risk of flooding this spring.

Dave Campbell says he wouldn't categorize the risk as higher or extreme.

"At this point we do have a little extra water on the ground in the snow and it's going to depend on how it melts going forward. I would say there certainly is flood risk with that modest increase because of the snow pack," says Campbell.

A year ago several areas were hit hard by flooding in June, specifically around Sicamous, Enderby and the Central Okanagan.

Campbell says that flooding was due mainly to large dumps of rain into already swollen creeks and rivers.

Earlier this week flooding occurred around White Lake Road in Penticton affecting St. Andrews Golf Course and other property in the area. There was also localized flooding from the Shuswap River just south of Enderby.

"What we did see was some pretty hot weather last weekend. It was unusually hot for that time of year and it's also within the time of year where we start to switch into melting," says Campbell.

"On those smaller creeks I suspect we saw the onset of a bunch of water coming down in response to that snow melt. In the bigger rivers it's still a bit early to get into that cycle."

Campbell says it is always hard to predict just how fast the snow will melt and what the flood dangers will be as a result.

He says there are several factors in play.

"When we see more snow on the ground that's more water that's available to melt and things like flood risk are increased," says Campbell.

"How warm it is affects how fast it melts and whether we get any additional inputs of water from rain. Any one of them on their own can certainly cause issues."

The last snow pack readings March 1 showed the Okanagan, in general, had a snow pack of 115% of normal.

Campbell says he expects the April 1 numbers to be about the same or a slightly lower.

"That's kind of at the threshold where we would see a very modest increase in seasonal flood risk."

He says 120% or more could result in a more definitive increase in flood risk.

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