Weather forecast still a cause for concern

Weather the past few weeks has favoured those on flood watch, with cooler weather slowing the melt of snow from high elevations around the Okanagan.

Weather the past few weeks has favoured those on flood watch, with cooler weather slowing the melt of snow from high elevations around the Okanagan. But the forecast of hot weather for a few days, then warm rain, may turn that around.

In some instances there is record or near-record amounts of snow remaining in the hills, and local water utilities report their upland reservoirs are full and spilling—if they’re not still frozen and covered in snow.

That means even more water running off into streams headed for Okanagan Lake in the valley bottom, and most are already nearly at capacity.

Black Mountain Irrigation District manager Bob Hrasko says they expect to have twice the amount of water they will need to fill reservoirs Loch Long, James and Fishawk Lakes and the Belgo Reservoir.

The first three are still iced over, he noted, and the road to the Belgo Dam has been washed out.

Because the snow melt at high elevations is so late this year there’s a record high amount of dense, wet snow up there for this point in the year, he noted.

He calls it ‘snow ripening’ as it becomes less deep, but denser and has a higher water equivalent.

The ground is saturated, so what melts now runs off instead of going into the ground first, he says.

The worry is that it might all come off at once as we get closer to summer and hotter, longer days.

“Our biggest concern is how quickly it comes off. If it’s sudden there can be erosion, scouring and gouging of the creek channels,” he explained.

“We have no control over temperatures. You have to have a healthy respect for Mother Nature. We’re watching out for obstructions in creeks. That’s the problem,” he noted.

High water can wash out a tree, which can obstruct high water flows, and the runoff finds a new route, causing flooding in an unexpected place downstream, he explained.

In the South East Kelowna Irrigation District, manager Toby Pike is happy to be out of the drought which caused concern during the past few years in his district.

Both his reservoirs, McCulloch and Turtle, are full and spilling, and his staff are doing their best to moderate downstream flows now, using the district’s diversion ditches.

He admits he is concerned about the damage high flows could do to infrastructure, and says he’s never seen so much snow in the upper watershed.

“Although 2009’s drought seems like a distant memory this year, next year we could be right back at the drought stage again,” he commented.

He would like to be able to keep some of this year’s snow just in case, but he concedes it’s likely to melt away, despite his wishes.

This year there won’t be any extraordinary conservation measures in SEKID, but the regular water regulations will continue to be enforced, so there’s no waste.

That’s also true in the Rutland Waterworks area of Kelowna, which is serviced by a series of wells rather than surface water.

Assistant manager Kevin Reynolds said they’re in good shape, but there isn’t as much variation in well levels as there is changes to surface water.

During the drought years, well levels did drop slightly, but he hasn’t yet noticed a rise as a result of this year’s abundant supply of surface water.

The district has 19 wells, 15 of which are used during peak periods, and 12 of which are used normally. They range in depth from 45 to 90 metres.

In West Kelowna, utilities supervisor Al Patterson said water regulations are still in effect there too, even though there are no concerns about the amount of water available in storage this year.

There is still ice on the upper elevation storage reservoirs such as Tadpole Lake, but he expects all their chain of storage lakes will fill this year.

“We’re in good shape,” he commented.

With water flowing fast and high in local creeks, people are reminded to keep children and pets well away from the edges of waterways.

jsteeves@kelownacapnews.com

 

Kelowna Capital News