BC Hydro is preparing for a potential high water year in the Columbia, which could require storing additional water in both Kinbasket Reservoir and Arrow Lakes Reservoir for flood control. In a media release, Hydro said that the Columbia and Kootenay facilities, slow snowmelt and dry summer weather could mean business as usual for the Columbia and Kootenay facilities; however, rapid snowmelt and heavy rainfalls could mean spill releases and above normal reservoir levels through the summer and fall.
Currently, snowpack levels on both the Canada and U.S. side of the border are higher than average. And with the cooler, wet weather this spring, snow is still accumulating at higher elevations. High snowpack and above-average spring rainfall means that runoff forecasts for the Columbia basin have continued to increase with each forecast update. The current runoff forecast for the Columbia basin (Canada and U.S. combined) is 130 per cent of normal (from April to September).
This is creeping closer to the last big water year in 2012 when the run-off was 135 per cent of average, higher than in any year since construction of the Columbia River Treaty dams. In 2012, BC Hydro coordinated the operation of Kootenay and Columbia facilities with the U.S. and other partners to maintain downstream river flows well below peak flows experienced prior to dam construction. Flood operations in 2012 involved spill releases from Revelstoke Dam and extra water stored in Arrow Lakes, Kinbasket and Duncan Reservoirs.
Like the weather, long-term forecasting is inherently uncertain due to the unpredictability of future events. Reservoir levels will depend on actual runoff volumes and patterns, system electricity demands, any upstream storage operations and Columbia River Treaty discharge requirements.
BC Hydro hydrologists, engineers and dam safety professionals say they will continue to closely monitor conditions and we will send regular advisories by email as conditions change.
For more information, BC Hydro will be hosting an annual operations update meeting in Revelstoke on June 22 at the Revelstoke Community Centre from 4–7 p.m.