Residents and businesses around Kootenay Lake can expect seasonal water levels to begin rising after officials declared the start of the spring freshet on April 30.
At 12 a.m. PT, “the commencement of the spring rise” of Kootenay Lake began under the 1938 International Joint Commission order, which governs how high the lake can rise each year. The International Kootenay Lake Board of Control made the decision after consulting FortisBC, which operates the Corra Linn Dam.
The declaration allows FortisBC to begin storing more water in the lake, a shift that typically leads to higher shoreline levels through the spring and early summer. For property owners, boaters and communities along the lake, that can mean changing shoreline conditions, including reduced beach areas and higher water near docks and infrastructure.
Under the order, the lake can rise to a maximum elevation of 1,743.32 feet as measured at Nelson. That level is typically reached in summer once snowmelt runoff subsides.
The timing of this year’s declaration, 12 to 14 days later than in 2024 and 2025, reflects a slower start to the melt season. Cooler and variable temperatures at higher elevations have delayed runoff, though increasing temperatures are expected to accelerate melting in the coming weeks.
Snowpack at low and mid-elevations has largely disappeared, while higher elevations remain near peak levels and are beginning to melt. As a result, inflows to Kootenay Lake are rising and are expected to continue increasing over the next month.
Before the declaration, the lake level at Queens Bay, B.C., was 1,744.69 feet (531.78 metres) on April 29 at 12 a.m. PT, already above the allowable rule curve. However, officials said outflows were limited by the natural restriction at Grohman Narrows, not the Corra Linn Dam, and FortisBC remains in compliance with the IJC order.
The freshet period, when snowmelt drives higher river and lake levels, will continue until the lake reaches its seasonal peak. Officials said they will continue to monitor conditions and provide updates, with a followup report expected after peak levels are recorded.
Real-time lake levels and updates are available through the board and FortisBC websites.
