Due to a lower snowpack, water levels at Lake Koocanusa are expected to peak roughly 10-15 feet below reservoir capacity in August, according to the U.S. Army Corps of Engineers.
Steve Barton, the USACE chief, Columbia Basin Water Management Division, said the snowpack is currently between 75-80 per cent of average and that there is a very low risk of flooding in the Koocanusa area.
“There’s a very low risk of flooding of the Kootenay system this year and as we’ve been operating at minimums at the project for much of the period between Jan. 1 to when we restarted refill operations, we’re trying to conserve water so that we have as much to work with this year as we can, given the expected dry conditions,” said Barton.
The reservoir, which services the Libby Dam, has a maximum elevation capacity of 2,459 feet. Barton notes that residents living around Lake Koocanusa will see lower water levels than normal at the summer peak.
The lower than average snowpack is likely to affect river systems across Columbia and Kootenay basins, added Darren Sherbot, Manager, Operations, with BC Hydro.
“For context, across the rest of the system in the Columbia, we have seen similar low water supply forecasts, so our big water reservoirs — Kinbasket, Arrow, Revelstoke, Duncan,” he said. “So it’s not just Koocanusa that’s facing the challenges this year, it’s across the whole Columbia Basin on the Canadian side as well.”
Sherbot added that this year’s water levels are shaping up the seventh lowest in nearly 60 years of record keeping.
“So for operations from our Duncan reservoir and our flows to the Kootenay river systems through the canal plants, there’s sufficient water there to meet our minimum fisheries flows for bull trout, Kokanee, rainbow trout downstream throughout the year as well, but we’ll be closely watching as the use will be on Koocanusa to manage our water supply,” Sherbot said.
Across the border, the U.S. Fish and Wildlife Service is also monitoring the flows to and the resulting impacts on spawning sturgeon.
Jason Flory, a biologist with the organization, said a water flow ‘pulse’ was stretched out for a longer period of time at a lower level rather than shooting for peak flow release.
“What we found was after the spawning season was over and we downloaded the telemetry data, we got more spawning adult sturgeon upstream of Bonner’s Ferry, where we’ve been trying to get them for years, than we’d ever seen in the past,” said Flory.
Flory said that a fertilized sturgeon egg was collected upstream of Bonner’s Ferry for the first time ever, meaning that there is some spawning occurring in that area.
“It’s the first time we’ve seen any of that going on,” Flory said.
The Kootenai Tribe of Idaho has also been instrumental in aiding the sturgeon recovery effort, leading habitat restoration projects along the Kootenay River.
BC Hydro has been touring communities in the Basin regions to update the public on expected water levels and flows and resulting impacts on local waterways. The crown corporation is also serving as a technical advisor in the current Columbia River Treaty negotiations between the Canadian and American federal governments.
The treaty is a 60-year water management agreement between the two countries that provides for power generation and flood risk management in the U.S. through the construction of four dams — three in Canada and one in Montana.
However, the construction of the dams flooded approximately 110,000 hectares of land, impacting the environment, farming, forestry, tourism and Indigenous communities and traditional territories.