If you were thinking Kootenay Lake right now looked lower than it has ever been, your analysis would be correct.
The lake level is sitting nearly a metre below its normal height, said Merrell-Ann Phare, Canadian commissioner with the International Kootenay Lake board of control.
“Kootenay Lake remains below its historical minimum values, and the B.C. drought notifications are still classifying it as very dry in the East Kootenay and extremely dry in the West Kootenay,” she said during the latest board public meeting on Sept. 22.
The board presented information on Kootenay Lake water level management — Kootenay Lake and the operation of Corra Linn Dam are under the International Joint Commission’s Orders of Approval — included an overview of lake levels for 2021 to date and then fielded questions and comments from the public in a virtual venue for its public meeting.
Phare acknowledged the very extreme concerns West Kootenay residents have endured in the last few months — including record hot conditions, record low Kootenay Lake levels and very serious wildfires throughout the region — in opening the meeting of the board.
It was an interesting year, said board member Martin Suchy of Environment and Climate Change Canada, with near normal snowpack conditions, a dry spring and it was very hot in the summer.
Even into May the snow pack was still near normal or above, even though it was a dry spring.
“That is enough to present a flood risk in a basin, but it’s not necessarily enough to guarantee a flood. In a year like this, floods would only happen if you had intense heat waves, or large, rain on snow events,” Suchy said.
“This year we were spared any of that, and in fact, we had a very subdued freshet, and that’s because we had very moderate temperatures through May … and it resulted in a very gradual snow melt.”
When the heat dome arrived in June, by that time most of the low elevation snow had melted so it didn’t affect the freshet, he added.
When the spring rise was declared on April 21 — it peaked at 532 metres by June 5 — lake levels decreased substantially after that, falling to 530 metres by Sept. 4.
But it was minimum inflows into the lake from tributaries — from late July to just recently — that contributed to record low lake levels for this time of the year, said Suchy.
Sign of the salmon
When the floor was open for questions, Regional District of Central Kootenay (RDCK) Area E director Ramona Faust — whose area is largely centred around the Kootenay River valley — wondered about the effect of the low water on shoal spawning kokanee salmon, fish that spawn on the shore and beaches of the lake and river.
Many lake residents were alarmed at the low level of the lake because it affected the shoal spawning kokanee, said Faust.
Chair of the board and a member of Environment and Climate Change Canada, Dave Hutchinson, said one of the things being done this year is the management of the lake to 530-metre elevation — down one metre — to enhance the spawning capacity.
“But I understand that the shoal spawners are a real concern for basin residents. And, in the future, this is something that we, as a board, are going to be considering for future projects,” he said. “We would need to see where we sit in terms of our mandate, but it is something we would like to look at in the future.”
Ted White, BC Ministry of Forests, Lands, Natural Resource Operations and Rural Development, said the concern would be addressed.
“We take this question and concern to the ministry and if there are any opportunities to address it and bring it forward, we will,” he said. “Currently, there aren’t any planning processes going on, but it’s good to have this raised again and look at what options we do have.”
This was the fourth time since 2012 that the lake level has been lowered to accommodate kokanee shore salmon spawners, Hutchinson explained.
One person wondered if the numbers of kokanee in the cohort of shoal spawners increased as a result of the repeated draw downs. Hutchinson did not know but waiting for data on what the spawning success rate was.
Report shoal sightings
People are being asked by FortisBC to spot kokanee found spawning along the beaches of the West Arm of Kootenay Lake.
Called “shoal spawners,” the kokanee are being studied by the Columbia Operations Fisheries Advisory Committee or COFAC, to determine how Kootenay Lake water levels influence the spawning success of these fish.
COFAC has found the West Arm shoal spawning kokanee are “genetically distinct” from West Arm tributary spawning kokanee. However, to help these fish, the lake levels is drawn down to 530 metres at Queen’s Bay for a one-month period.
That lower level allows the fish — from mid-September to mid-October — to deposit their eggs in the lower elevations on the shoals, with the reservoir filling again for the winter.
This move will help the lower fish nests create a successful spawn in spring — during a year of peak spawn like 2021 — when the lake level is reduced and fewer of the spawning salmon are stranded.
If you see kokanee spawning on the lake shore, call the B.C. Fish and Wildlife Branch at 250-354-6333 and report approximately how many kokanee you see and the precise location where you saw them on the lake.
The Boundary Waters Treaty has been in place since 1909 between the U.S. and Canada relating to boundary waters and questions arising between the two countries.
Through the treaty the joint commission was established and, further, the construction of the Corra Linn Dam in 1938 brought regulation of water levels. Although Kootenay Lake is in Canada, FortisBC’s Corra Linn Dam can affect water levels up the Kootenay River into Idaho.
Hutchinson said Grohman Narrows is a natural flow constriction that has historically controlled the outflow of Kootenay Lake prior to the dam construction. Directed by FortisBC’s predecessor to dredge Grohman Narrows (completed in the early 1940s), the capacity of the Kootenay River was increased as was the ability to direct flows.
“Even with the dredging of Grohman Narrows to increase the capacity of the channel, the Grohman Narrows to this day still act to control Kootenay Lake levels at certain times of the year,” Hutchinson said.