Zosel Dam

We regulate Lake Osoyoos by operating gates at Zosel Dam at Oroville on the Okanogan River, at the Washington state border with British Columbia, Canada. Lake levels are mandated as agreed upon by the International Joint Commission of the Boundary Waters Act between the United States and Canada.

The lake hosts summer homes and recreational activities, and supplies irrigation water on both sides of the border.

June 14, 2022, high flow at Zosel Dam near Oroville, Washington. Photo by Jay O'Brian.

Current conditions

June 15, 2022 – Water levels have risen to 913 feet at Lake Osoyoos and water will begin to overtop the weir. As water levels rise there may be some localized flooding.

We are aware of the rising levels. Dam operators at the Zosel dam have opened all the gates to release water and are monitoring the situation closely. 

The lake’s water levels change based on spring runoff and water usage throughout the summer. The water levels are also influenced by occasional seasonal conditions, such as droughts.

To track the progress of lake levels in real time, as well as find additional information, visit the USGS web page for Osoyoos Lake.