Elected officials and evacuees alike breathed a sigh of relief Saturday afternoon, as the danger of a flash flood passed and people who live below Chute Lake were allowed to return home.
The evacuation order for 47 homes was rescinded about 24 hours after the Regional District of Okanagan-Similkameen issued it for residents in the Indian Rock area downhill from the problem.
At the south end of the lake is a concrete dam - also called a weir - designed to maintain a maximum depth in the lake. When too much water enters the lake, it spills over top of the dam, thereby maintaining the desired depth. Once over the dam, the water is supposed flow into a small creek then through four 90-centimetre culverts under the Elinor Lake Forest Service Road and into Chute Creek.
Due to heavy rains last week, however, a large volume of water topped the dam by as much as 60 centimetres then overwhelmed the culverts and began building up behind the forestry road. Sinkholes emerged in the road Friday, and it was feared the road could give way and unleash a dangerous torrent of water down the slope with the potential to wipe out everything in its path.
Excavators were brought in to dig out the section of road over the culverts, and that relieved the water pressure in a controlled manner. A berm will be built on the road at either end of the break until a long-term fix can be devised.
“It’s made everyone comfortable that we can go ahead and let folks back into their homes,” said Karla Kozakevich, the RDOS director for Naramata.
She said Chute Lake has returned to its normal level and the dam is working as it’s intended to.
“It always has,” Kozakevich. “it’s just that there was so much more water than anticipated.”
Forty-seven homes were covered by the evacuation order and 21 people spent Friday night at a hotel in Penticton.
Evacuee Dave Davenport, who owns a home on Indian Rock Road, said he was entertaining company Friday afternoon when he was presented a copy of the evacuation order by search and rescue personnel. He’d already gotten wind of a possible evacuation, so the retired corporate lawyer was already packed and spent the night with his sister in Penticton.
“The evacuation was extremely, and pleasantly, well-organized,” Davenport said.
Despite the seriousness of the situation, he didn’t fear for his home or his property.
“The road that they were talking about giving way is 20 miles up the mountain, and that water has got a long way to go,” Davenport said. “I think the problem they had is they didn’t know where the hell the water was going to go.”
RDOS chairman Dan Ashton said memories of the Testlinden Dam collapse and subsequent mudslide near Oliver in 2010, which destroyed five homes, were fresh in officials’ minds, so they exercised extreme caution to prevent a repeat.
Ashton also speculated that the 2003 Okanagan Mountain Park fire may be partly to blame for the surge of water into Chute Lake, because it burned away much of the vegetation that would normally sop up torrential rain and meltwater.
Kozakevich, who’s only been in office five months, praised the work of the RDOS and Ministry of Forests, Lands and Natural Resource Operations staff members who remedied the problem at Chute Lake and took care of the evacuees.
“As a new director, you want to help and you feel helpless at times, but you quickly learn how great everyone is and you quickly put your confidence in them,” she said.
The Chute Lake dam is privately owned by wine giant Mark Anthony Properties and was last inspected in 2011, according to Vivian Thomas, a spokesperson for the B.C. Ministry of of Forests, Lands and Natural Resources Operation.