Wind and rain in forecast add to flooding concern

Wind and rain in forecast add to Central Okanagan flooding concerns

Central Okanagan residents, already hit with flooding as a result of overflowing creeks and near-record high water levels in Okanagan Lake, are being warned winds are in the forecast and the level of Okanagan lake is expected to rise a further 10 to 15 centimetres.

EOC director Brian Reardon issued the warnings Friday, urging residents living along the lake, near creeks and in low-lying areas to bolster their flood protection.

He said the authorities are adding as much as 15 centimetres to the height of flood protection on public property and private landowners should follow suit.

While variables change daily that could affect lake levels, he said it was necessary to warn the public “out of a sense of caution.”

Yesterday, Environment Canada reported the lake level was 343.1 metres, a two-centimetre rise overnight from Monday and 12 centimetres higher than it was a week ago. And it said a new weather system is moving into the area that could bring wind and rain.

On Friday, Reardon predicted the hot weather over the weekend would help keep the lake level rising by melting more snow at higher elevations, especially above Kelowna’s Mission Creek. That creek is the biggest contributor to Okanagan Lake.

“What we do know today is that the temperatures are forecast to stay in the low 30s for the next four to five days and well into next week there is the potential for a significant wind event similar to what we experienced this last Tuesday,” said Reardon on Friday. “We’re looking at Wednesday or Thursday for that to be occurring.”

On Tuesday, the EOS said the expected winds will not be as strong as they were in last week’s windstorm, this time gusting to only 25 kilometres per hour. Last week, gusts were recorded in excess of 70 kilometres per hour. That windstorm toppled trees, tore docks from their moorings on the lake, submerged others and knocked out power to hundreds of homes in the area for several hours.

According to Reardon, the official response to the flooding situation in the Central Okanagan over the last three weeks has cost an estimated $3 million so far, with much of it borne by the province through Emergency Management B.C. That cost, however, does not include the financial impact on private property owners to protect their properties.

In addition to the rising lake level, Reardon said Mission Creek flows are expected to increase significantly over the next few days.

“There is approximately 80 per cent of the snow pack in the higher elevations still there,” he said. “Due to the unseasonably high temperatures, the next few days will be critical.”

He added that with nowhere for the additional snowmelt to go, there is a high potential for “back water” at the mouth of Mission Creek, meaning water that would normally flow into the lake may back up and cause flooding in the area adjacent to the creek, possibly as far back as the Lakeshore Road Bridge in Kelowna.

As a result, crews have bolstered flood protection measures between the Lakeshore Bridge and the mouth of creek on Okanagan Lake. Residents living along the creek, especially those closer to the lake, are urged to reinforce flood protection around their properties due to the rising lake level and the potential for the back water effect.

He also reiterated the call for boaters, if they feel they must go out on the lake, to not only be careful as there is a great amount of debris floating above and below the surface but also to slow down near shore so as not to cause potentially damaging wakes from their boats. Wakes, he said, can cause erosion, or in some cases, flooding to lakefront property.

The EOC is also advising residents to make sure they properly build sandbag walls in a triangular in shape—more bags on the bottom of the stack—for better stability and not to lean sandbag walls up against existing structures because wave action could bring them down.

For more information about flooding the go to cordemergency.ca.