Even more snow in hills boosts flooding worries
Snowpack was 152% of normal on April 1, and official says it has increased 5-15% since then
The Okanagan snowpack has increased significantly since April 1, when it was already at its highest level in 38 years, and officials are concerned about smaller rivers flooding as temperatures rise this week.
“This will mark the onset of the broader freshet season across the province,” said David Campbell, head of B.C.’s River Forecast Centre.
The transition from snow accumulating to melting generally occurs in the middle of April, but the melt has been delayed by about a week in most areas, and by two or three weeks in low to middle elevations, said Campbell.
On April 1, the snowpack in the Okanagan was at 152 per cent of normal, tied with April 1999 for the highest snowpack dating back to 1980.
Since April 1, the snowpack in the Okanagan has increased by about five to 15 per cent.
“We were already extremely high, and we’ve continued that trend,” said Campbell.
Across the province, the average snowpack has increased from 106 per cent of normal on April 1 to about 114 per cent of normal on April 22.
The official numbers will come out in the River Forecast Centre’s next report on May 7.
In the next week, the biggest concern is the effect of the melt in low to middle elevations on smaller tributary creeks, said Campbell.
Environment Canada is forecasting highs in the low-to-mid-20s around Penticton this week, and Campbell says the sustained warm weather could cause problems as the snow melts.
Shaun Reimer, section head of public safety and protection with the Ministry of Forests, Lands and Natural Resources, said the ministry is currently dropping the level of Okanagan Lake by 1.5 centimetres per day.
Okanagan Lake is currently about 106 cm below full pool, 61 cm lower than this time last year.
“Based on the . . . forecast of the amount of water expected to come in between April and July, it should be manageable,” said Reimer. “That of course is not taking into account if we get some wet weather, and if the water comes in very quickly, much like it did last year.”
Reimer said he expects Okanagan Lake to start rising as this week’s warm weather initiates the start of the snowmelt.
Flooding has already been a problem in the Regional District of Okanagan-Similkameen this spring, where an evacuation order for 12 properties north of Oliver was issued on Saturday.
The regional district warned that the flooding posed an immediate danger to “life safety,” and another 17 addresses were put on evacuation alert, told they must be ready to leave on a moment’s notice.
The Osoyoos Indian Band also had several homes evacuated on Friday, due to concerns about a potential landslide, but residents were allowed to return Saturday.
Last week, the provincial government approved financial assistance for those impacted by overland flooding or landslides.
Melting snow and soggy ground makes this a particularly dangerous time of year to be around rivers and streams, and people should be cautious near waterways, Campbell said.
“We get a lot of ground saturation. The banks of rivers are very unstable,” he said. “Whether there’s a flood warning out or not, they can be very hazardous this time of year.”