Columbia River levels near Trail are expected to shift sharply early this week.
When combined with outflows from the Kootenay River, water levels at Birchbank will decrease by 3.4 feet on Sunday and Monday, then rise by six feet on Tuesday and Wednesday, according to BC Hydro.
The utility advises the public to make safety a top priority during this period of rapid change.
The advisory comes alongside BC Hydro’s latest report showing forecast runoff from April to September 2025 is now expected to reach 76 per cent of normal, as measured at The Dalles, Oregon, the key reference site for Columbia Basin water forecasting.
In 2024, observed runoff for the same period was 75 per cent of normal in the Canadian portion of the basin and 74 per cent basin-wide.
As of July 11, Arrow Lakes Reservoir, measured at the Fauquier gauge, stood at 1,427 feet.
It drafted 2.3 feet over the past week and is projected to fall to 1,418 feet by the end of July.
The reservoir reached its most recent high of 1,431 feet on June 19 — about 13 feet below full.
Its lowest elevation so far this year was 1,388 feet on Jan. 31.
Duncan Reservoir is currently at 1,877 feet, after rising six feet over the past week.
It is forecast to reach 1,890 feet by the end of July.
The reservoir last peaked at 1,879 feet on Aug. 4, 2024, and hit a low of 1,801 feet on April 25, 2025.
BC Hydro notes that reservoir levels are shaped by a mix of snowpack conditions, inflows, weather patterns, and energy demand.
The utility also cautions that forecasting — both short and long term — remains uncertain due to the unpredictability of future events.
