Spring Freshet Update
The spring freshet in the Okanagan/Okanogan and Similkameen basins has started, but unseasonably cold temperatures this spring have limited snowmelt and runoff.
High-elevation snow pillow gauges at Blackwall Peak in the Similkameen Basin (at an elevation of 1,940 meters or 6,365 feet) and Mission Creek in the Okanagan Basin (at an elevation of 1,780 m or 5,840 feet) are both currently reporting above-normal snow depth and no significant spring snow melt.
As a result, the Osoyoos Lake level is 277.74 m (911.22 feet) as of May 20. This level is below normal, but remains within the range of allowable lake levels defined by the International Joint Commission Orders of Approval for Osoyoos Lake (Figure 1). River flows and lake levels are expected to increase as temperatures increase and the high elevation snowpack starts to melt.
Early April and early May forecasts of Similkameen River total flow volume, Okanagan Lake net inflow and Okanagan Lake level indicate the drought criteria defined within the Orders of Approval for Osoyoos Lake will not be met this year. The board has notified the Applicant to the Orders (Washington Department of Ecology) that Osoyoos Lake must be operated under the normal rule curve as defined by Condition 7 of the Orders of Approval.
Please monitor this site for further snow melt and river conditions updates as the temperatures and freshet begins to ramp up. Real-time Osoyoos Lake levels are available on the International Osoyoos Lake Board of Control website.
Figure 1: 2022 Osoyoos Lake Levels (solid green) and allowable range under the normal rule curve defined by the International Joint Commission Orders of Approval for Osoyoos Lake (solid black).