
‘Functional flows’ are expected to be the hallmark of the new Columbia River Treaty and its agreement-in-principle in order to prevent dramatic drops on the river in the West Kootenay, says the treaty’s Canadian negotiating team.
Kathy Eichenberger said there are current lessons to be learned from the large variations in Columbia River flows below Castlegar and on toward the U.S. border.
When she was asked about a recent dramatic drop in the Columbia — over three feet in one day — that was damaging to aquatic entomology and fish that utilized the shoreline habitat, she felt more answers were on the way.
“We are looking at more functional flows to improve the aquatic values including fisheries, sturgeon and cottonwood downstream of the Arrow Lakes; so we are looking at that modeling … and that is a big focus of the work we are doing,” she said recently during a webinar reveal of the agreement-in-principle (AIP).
While the AIP is a step forward towards modernizing the Columbia River Treaty, it is not a legally binding document and more work is being done, said Eichenberger. Until a modernized treaty has been finalized and accepted by both countries the current treaty remains in place.
Currently, the Columbia River Treaty (CRT) is operated for power generation and flood control objectives and — under the terms of the treaty — Canada is required to release more water during dry conditions in the U.S. to enable the U.S. to meet its firm energy requirements. There is no provision for Canada to reduce flows under drought conditions, said Eichenberger.
BC Hydro’s obligation is to operate the Columbia system under the terms of the CRT and — although BC Hydro can take steps to minimize impacts, such as holding back flows — it cannot prevent low levels due to drought conditions.
But for many people in the West Kootenay, the changes can’t come soon enough. Since 2018 there has been a huge range in the depth of the Arrow Lakes reservoir and some people in the webinar questioned if there were guarantees the lake levels would be maintained for ecosystem, recreation and travel values.
Eichenberger said under the AIP Canada does need to respect the 3.6 million acre feet of flood risk management water that is used for the United States, and to keep in mind that flood risk management is important as well for Trail and Castlegar.
“That’s where the intention is; there are multiple purposes for reservoir operation and how do you find that sweet spot?” she said. “If the reservoir is kept lower, but not too low, you would see all the greenery that gets lower down the banks. And the water level must be maintained to not flood that area very frequently. It also provides for a good level of recreation.
“The converse of that, if you go too low recreation suffers as well.”

The low levels of the reservoir observed in 2023 were due to a combination of below average snowpack during the winter of 2022/23, the early depletion or melt of the below average snow levels in May, and the following severe drought conditions observed in the Columbia basin, noted a reply from the treaty negotiation team.
“The combination of low inflows into the reservoir and required Columbia River Treaty discharges resulted in an exceptional deeper draft (lowering) of Arrow Lakes Reservoir over the summer and fall,” a website on the CRT read. “Additionally, water releases from Kinbasket Reservoir that might otherwise keep Arrow Lakes Reservoir levels higher were managed, similar to prior low inflow years, to ensure sufficient water storage for winter energy supply for Revelstoke and Mica Generation Stations.”
It was conceded that while levels and drawdown caused a number of significant challenges on the ecosystem, the reservoir did operate as expected under the terms of the CRT and severe drought conditions.
“Should similar conditions occur in the future under the current treaty, similar operations would be expected,” the website stated.
Eichenberger said Canada, B.C. and the Ktunaxa, Secwépemc and Syilx Okanagan Nations are seeking improvements in the treaty through negotiations with the U.S. to reduce the type of impacts seen on Arrow Lakes.
“The additional flexibility the Canadian negotiation delegation is seeking would allow B.C. to adjust its treaty dam operations to support ecosystems (including fish), Indigenous cultural values, and socio-economic interests,” noted a response from the negotiation team.
“There is river management scenario modelling underway that is informing how to use any new flexibility.”
Part of this involves looking at different elevations throughout the year on Arrow Lakes Reservoir, with research to determine objectives for the modelling process being led by the Ktunaxa, Secwépemc and Syilx Okanagan Nations in collaboration with federal and provincial governments, the Columbia River Treaty Local Governments Committee and environmental non-governmental scientists and technical consultants.
Boat launches
As part of BC Hydro’s water licence, they are required to provide access to Arrow Lakes Reservoir during the peak recreation season.
To meet this requirement, BC Hydro completed construction and upgrades of boat ramps for use during the recreation period, which is generally considered to be from mid-June to mid-September.
The comptroller of water rights has confirmed that, subject to meeting maintenance requirements, BC Hydro has met their obligation to provide access to the reservoir.
Source: CRT online Q and A, March, 2024