Osoyoos Lake Climate Change Vulnerability: Phase 1 - Similkameen Basin Hydrologic Model

The Osoyoos Lake Board of Control is developing a multi-year, multi-phase project to analyze the vulnerability of Osoyoos Lake and the relevant IJC Orders of Approval to a projected shift in the climate and hydrology of the Okanagan/Okanogan and Similkameen Basins. Inflow to Osoyoos Lake is mostly regulated by outflow from Okanagan Lake; outflow from Osoyoos Lake, when the stage of the Similkameen River is high, is not controlled by Zosel Dam operation (as it normally is), but by the level of the Similkameen River that joins the Okanogan River immediately downstream of Zosel Dam. Consequently, in order to effectively manage Osoyoos Lake levels in the future, the Osoyoos Lake Board of control needs to consider the hydrological response of both the Similkameen and the Okanagan Basin to projected climate change.