Skip to content

Below average summer levels forecasted for Arrow Lakes Reservoir

“This is not the first time we’ve experienced conditions like these … “
Arrow Lakes Reservoir. Photo:

After a dry spring in 2023, BC Hydro says it is now projecting lower reservoir levels in many areas of the province.

Conditions have culminated after sustained periods of dry weather commencing in the fall of 2022, below average snowpack this winter in most of BC Hydro’s basins, lower spring and summer precipitation, and higher energy demand due to atypical weather patterns.

With last winter’s snow mostly gone, the utility company notes that reservoir levels for the balance of the summer will now be significantly influenced by the amount of summer and fall rain amounts.

“This is not the first time we’ve experienced conditions like these, and we want to assure customers that we have enough power to meet the demand and we are taking proactive steps to manage the lower-than-average inflows,” BC Hydro explains. “Our priority has – and will always be – delivering clean, safe, and reliable power to our customers.”

In the Columbia Basin, BC Hydro is currently forecasting below average summer levels for Arrow Lakes Reservoir due to severe drought conditions. As of July, the lower Columbia Basin is in drought level 4 (of 5 being the most severe).

This is similar to conditions in much of the province.

This year’s basin snowpack was below average due to low precipitation in the fall and winter of 2022/23. The forecast runoff for 2023 (as of July 20) is 76 per cent of normal or placed in the third driest year on record since 1949.

Additionally, freshet (peak snow melt) was early and compressed due to above seasonal temperatures during May.

This caused accelerated snowmelt and depleted much of the snowpack by the end of May. Since June, BC Hydro says that inflows have been receding to new record low levels.

In the absence of further snowmelt, water levels will be dependent on the amount of summer rain.

Arrow Lakes Reservoir water levels are currently (July 24) at 433.8 metres (1,423.4 feet) and are expected to continue to draft to reach 431.9 metres (1,417 feet) by the end of July and 427.3 metres (1,402 feet) by the end of August.

However, the levels are expected to remain above the Arrow Lakes Reservoir water license minimum level of 420 metres (1,378 feet).

While these levels are lower than typical, they are not unexpected as similar low summer levels were observed in the very low inflows years of 2001 and 2015.

The last time the reservoir reached similar levels was in 2015, when Arrow Lakes Reservoir drafted to 432.2 metres (1,418 feet) at the end of July and 428.8 metres (1,407 feet) at the end of August.

In 2001, Arrow Lakes Reservoir was drafted to 430.1 metres (1,411 feet) at the end of July and 428.8 metres (1,407 feet) at the end of August.

Note: This forecast is subject to change based on a number of factors, including weather, load requirements, inflows, and other variables. Updated information is provided via email every Friday and is also available by calling BC Hydro at 1.877.924.2444.