Flooding along Adams Road in Kelowna last year. Photo credit: Capital News files

Snowpack level increases Okanagan Lake dam discharge

Extreme weather changes concern on the flooding front

The higher than average snowpack buildup across the valley so far this winter would normally be a leading indicator for controlling the level of Okanagan Lake.

But after the extreme changes in last year’s winter and spring weather conditions, Shaun Reimer says extreme weather patterns is raising unknowns about managing the lake level.

As the section head for public safety and protection at the regional office for the provincial Ministry of Forest, Lands, Natural Resource Operations and Rural Development, Reimer is in charge of releasing water from Okanagan Lake at the Penticton dam.

“The shadow hanging over us right now is not from what happened last year, but rather climate change and the lack of understanding about where that is going to lead in causing extreme weather pattern changes,” said Reimer.

Related: Climate change impacts Okanagan Lake

“We have computer charts that dictate how to react to more snowpack years or drought years in that regard. But we certainly didn’t expect those conditions to happen in the same year. That has been the radical change.”

That radical change was evident from the fall of 2016 through to the spring—heavy precipitation from October into December, low snowfall accumulation from January to March, then intense snowfall followed by record rainfall from March to May.

The end result was widespread flooding across the valley, costing millions of dollars for communities and property owners in damages.

Related: Kelowna mayor frustrated by residents’ climate change message

“It felt like someone was turning the light switch on and off the way the weather patterns were suddenly changing,” he said.

Reimer said the dam release schedule has been raised from 28 to 30 cubic metres/second, the maximum allowed that won’t damage the current Okanagan River sockeye salmon spawning run. He said the lake is being drawn down now in anticipation of the current snowpack melt, which currently is more than 130 per cent of normal.

“The aim now is to make room for that snowmelt the way we are heading at this point. The level of precipitation in May and June, which is normally our heavier rain months, is the wild card factor in the melting pattern of the snow,” said Reimer.

Last year, record high precipitation in the early spring caused a cavalcade of snowmelt water flow because the rain caused the snow to melt more quickly, coupled with a rising groundwater table already too saturated to off-set the sudden surge of water.

“Normally, our high water discharge rate is 60 cubic metres a second, and we got close to 80 at one point because of the flooding issues. But we don’t normally want to exceed 60 because that causes further flooding downstream because there isn’t the natural channel capacity to handle that kind of water flow,” Reimer said.

Related: West Kelowna demands review of flood factors

An internal review of how ministry staff addressed the extreme weather elements last spring leading up the flooding has been produced by a Vernon consulting firm. That report has been completed and is undergoing review within the ministry branches before being released to the public likely sometime in March.

To report a typo, email: edit@kelownacapnews.com.


@BarryGerding
barry.gerding@blackpress.ca

Like us on Facebook and follow us on Twitter.

Just Posted

Nomination period closes for Summerland Chamber awards

More than 130 submissions received for 81st annual Business and Community Excellence Awards

Death Café returns to Okanagan

Vernon, Kelowna and Summerland events toast touchy subject

Highway 97 rock slide north of Summerland beginning to stabilize

Costs of road work so far estimated at between $300,000 and $350,000

Family Day long weekend expected to be sunny and cool in South Okanagan

Flurries forecasted for the first half of the weekend, followed by bluebird skies and milder temps

More snow on the way for Okanagan-Shuswap

Up to 5 cm of the white stuff could fall across the Okanagan - Shuswap on Friday

VIDEO: Canada’s flag turns 54 today

The maple leaf design by George Stanley made its first appearance Feb. 15, 1965

Eight cases of measles confirmed in Vancouver outbreak

Coastal Health official say the cases stem from the French-language Ecole Jules Verne Secondary

Semi loses control on Highway 97A in Shuswap

Slippery roads contribute to crash of transport truck carrying tires

Plecas won’t run in next election if B.C. legislature oversight reforms pass

B.C. Speaker and Abbotsford South MLA says he feels ‘great sympathy’ for Jody Wilson-Raybould

Infighting at Kelowna Yacht Club makes it to court

Marc Whittemore, a local lawyer and prominent member of the club, filed a notice of civil claim Feb. 1

Workshop with ‘accent reduction’ training cancelled at UBC

The workshop was cancelled the same day as an email was sent out to international students

Former B.C. premier Gordon Campbell accused of sexual touching

Accuser went to police, interviewed by Britian’s Daily Telegraph

Syrian refugee responds to racism in Canada

Guest columnist Mustafa Zaqrit

Most Read