Zosel Dam

Zosel Dam is the only dam we own and operate. The dam's primary purpose is to maintain lake levels on Osoyoos Lake, which is on the boundary of the United States and Canada near Oroville. Lake levels are mandated by the International Joint Commission, a board made up of representatives from the U.S. and Canada.

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

Water behind Zosel Dam, with grass in the foreground and snow-capped hills in the background.

Zosel Dam near Oroville, Washington. Photo by Chad Mathews

Current Conditions

March 21, 2019

Lake Osoyoos water levels to rise earlier than normal

Osoyoos Lake is set to rise a month earlier than normal and we want residents to be aware.

Less than average snow levels are being reported in all watersheds in the region, and temperatures are on the rise. Because of this, the operator will bring the lake to its summer operational level earlier than usual to avoid water shortages and low flows later in the summer. The goal is to bring the lake to its maximum mandated operational level of 912 feet by early May, rather than by June 1.

We regulate the lake’s levels by opening or closing gates at Zosel Dam, near Oroville. This is done because of seasonal mandates agreed upon by the International Joint Commission of the Boundary Waters Act between the United States and Canada. The lake serves as a source of water for irrigation and summer recreation in both Okanogan County, Washington and Osoyoos, British Columbia.

Releases from Okanogan Lake to the north and snowpack runoff in British Columbia can impact lake levels at Osoyoos. And, during the snowpack runoff season, the level of the lake can rise sharply.

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