News Releases

Ice jams are accumulations of ice that partially block water from flowing downstream and can cause challenges to the operation of control structures such as the Zosel Dam at the outlet of Osoyoos Lake. Ice jams form at the shallow outlet of Osoyoos Lake during certain winter conditions. A new U.S...

The International Osoyoos Lake Board of Control (the Board) has declared drought conditions for Osoyoos Lake under the International Joint Commission’s (IJC) 2013 Supplementary Order of Approval . The Washington State Department of Ecology (Ecology) is the operator of Zosel Dam, responsible for...

Low water levels in Osoyoos Lake have exposed the shoreline. Credit: Town of Osoyoos. Osoyoos lake levels reached historical lows this winter following unusually dry conditions across the region. As a result the International Joint Commission (IJC) has approved a temporary operating variance for...

The water levels in Osoyoos Lake have reached historic lows due to dry conditions within the Okanagan basin. The lake level is currently 909.12 ft, which is the lowest on record (Figure 1). Water levels are likely to remain low until more water enters the Okanagan River system. Osoyoos Lake...

The International Osoyoos Lake Board of Control (IOLBC) is hosting a public meeting in Osoyoos, B.C., on September 17, 2025. All those interested in water levels, Zosel Dam operations and other IOLBC projects are invited to attend.  The event is from 6:30-8 p.m. (PDT) at the Sonora Community Centre...

As drought conditions affect the Okanagan/Okanogan and Similkameen Basins in Canada and the U.S., the International Joint Commission (IJC) has approved a request for a temporary variance to how Osoyoos Lake levels are managed this summer. These changes allow the operator of Zosel Dam to hold lake...

The International Osoyoos Lake Board of Control monitors hydrologic conditions in the Okanagan/Okanogan and Similkameen basins to inform the management of Osoyoos Lake levels. Conditions remained dry to very dry in southern British Columbia and northern Washington state throughout the summer of 2024...

Those interested in water levels, Zosel Dam operations and other projects and initiatives by the International Osoyoos Lake Board of Control are invited to a public meeting in Oroville, Washington, on October 3, 2024.  The event is from 6:30-8 p.m. (PDT) at the Oroville High School Library, 1016...

Spring freshet has largely concluded and the Osoyoos Lake level has reached its 2024 peak. The snowpack in the Okanagan/Okanogan and Similkameen basins was extremely low throughout the 2023-2024 winter. Since January 1, 2024, the British Columbia Snow Survey and Water Supply Bulletin has reported...

Osoyoos Lake levels are being maintained at a higher-than-normal level for this time of the year in anticipation of lower spring runoff due to lower-than-normal snowpacks. As of April 9, the Osoyoos Lake elevation is 911.81 feet (277.92 meters) and is at the historical maximum for the 1987-2023...

As of November 1, 2023, the Rule Curve for maximum and minimum Osoyoos Lake levels has changed for the winter period, allowing lake levels to be maintained between 909.0 feet and 911.5 feet until March 1, 2024 (Figure 1). Figure 1: 2023 Osoyoos Lake Levels (bright green) and allowable range under...

Those interested in water levels, Zosel Dam operations and other projects and initiatives by the International Osoyoos Lake Board of Control are invited to attend a public meeting in Osoyoos, British Columbia, on October 4, 2023. The event is from 6:30-8 p.m. (PDT) at the Sonora Community Centre...

The spring freshet in the Okanagan/Okanogan and Similkameen basins has come to an early end as snowpacks have been depleted and levels on both Okanagan and Osoyoos lakes have peaked and begun to decrease. Osoyoos Lake peaked at 912.10 feet (278.01 meters) on May 8 in response to runoff within the...

The spring freshet in the Okanagan/Okanogan and Similkameen basins has commenced as snowpacks have begun to melt due to above normal temperatures in the last week. The snow pillow gauge at Mission Creek (elevation 1,780 meters or 5,840 feet) in the Okanagan basin was above normal for this time of...

If you’re interested in activities by the International Osoyoos Lake Board of Control, it’s now easy to receive news releases in your email inbox. The Board has launched a new feature which enables people to sign up to receive periodic email notifications on news related to Board activities. The...

Climatological conditions within the Okanagan/Okanogan and Similkameen River basins varied during 2022, with the greatest impacts related to a cool spring leading to delayed snowmelt and a delayed freshest peak at Osoyoos Lake. While near-normal temperatures prevailed at the start of 2022...

Osoyoos Lake Board of Control public meeting: Wednesday, October 26, 2022, 6:30-8 p.m. (PDT) The International Osoyoos Lake Board of Control is holding its annual public meeting at the Oroville High School in Oroville, Washington, at 6:30 p.m. (PDT) on October 26. There also will be an option to...

Regulation of Osoyoos Lake by the Zosel Dam has resumed now that Osoyoos Lake levels have returned to within the rule curve. On July 27, the Osoyoos Lake level declined below an elevation of 912 feet (277.97 meters), the upper limit of the rule curve as defined by Condition 7 of the International...

The level of Osoyoos Lake reached 913 feet (278.3 meters) on June 23 in response to runoff within the Okanagan/Okanogan and Similkameen basins during the spring freshet (Figure 1). At this elevation of Osoyoos Lake, some beaches along the shoreline are inundated and wind or boat-generated waves may...

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...

After slowly declining since late July following a dry summer, Osoyoos Lake level reached the targeted winter operational elevation of between 909.45 to 909.55 feet in early December according to the Washington State Department of Ecology, which owns and operates Zosel Dam. Lake level is anticipated...

On November 15th, discharge of the Similkameen River began to increase rapidly. This was due in part to the landfall of a Category 5 atmospheric river causing heavy, sustained rainfall and rising temperatures resulting in additional runoff from snowmelt. A flood warning for the Similkameen River was...

The International Osoyoos Lake Board of Control is holding its annual public meeting regarding the regulation of Osoyoos Lake water levels and the related operations of Zosel Dam by the State of Washington under the International Joint Commission’s Orders of Approval.

Osoyoos Lake level reached the summer target elevation of 911.70 feet in late May, then crested to 911.82 feet (277.923 m) on June 15, below the maximum allowable International Joint Commission (IJC) Order of Approval rule curve of 912.0 feet.

The spring freshet in the Okanagan/Okanogan and Similkameen basins has begun as temperatures increase. The snow pillow gauges at Blackwall Peak in the Similkameen Basin (elevation 1,940 m) and Mission Creek in the Okanagan Basin (elevation 1,780 m) are near their annual peak and are both currently...

The International Osoyoos Lake Board of Control is holding its annual public meeting regarding the regulation of Osoyoos Lake water levels and the related operations of Zosel Dam by the State of Washington under the International Joint Commission’s Orders of Approval.

During the spring freshet, the level of Osoyoos Lake crested at 913.65 ft (278.481 m) on June 2 and decreased below the maximum level of the IJC (International Joint Commission) Order of Approval rule curve (912.0 ft) on Saturday July 18.

With flow of the Similkameen River declining since its recent peak on June 1, the backwater effect of the Similkameen River on the Okanogan River is decreasing. This allows for increased outflow from Osoyoos Lake and a corresponding drop in its level. Osoyoos Lake crested at 913.65 ft. (278.481 m)...

In compliance with the terms of the International Joint Commission (IJC) water management Order for Osoyoos Lake implemented by the International Osoyoos Lake Board of Control (https://www.ijc.org/en/olbc), the gates at Zosel Dam have been fully open since May 11 to allow for maximum outflow from...

Due to recent snowmelt in the high elevations of the Okanagan and Similkameen watersheds, Osoyoos Lake surpassed the 912.0 feet level (Plot 1) at 03:00 am PDT on May 14, 2020, with lake levels continuing to rise. The Applicant to the IJC Orders of Approval for Osoyoos Lake that operates Zosel Dam...

The International Osoyoos Lake Board of Control is holding its annual public meeting regarding the regulation of Osoyoos Lake water levels and the related operation of Zosel Dam by the State of Washington under the International Joint Commission’s Orders of Approval. The Board will provide an...

The International Osoyoos Lake Board of Control (Board) will allow for a broader range of water levels on Osoyoos Lake this summer to help limit the impacts of dry conditions in the basin. The board implements an Order from the International Joint Commission (IJC) that mandates a range of allowable...

In compliance with the terms of the International Joint Commission (IJC) water management Order for Osoyoos Lake implemented by the International Osoyoos Lake Board of Control ( http://www.ijc.org/en_/iolbc), the gates at Zosel Dam have been fully open since March 26 to allow for maximum outflow...

The level of Osoyoos Lake has been rising since late April when increasingly warm temperatures began to melt the Okanagan River basin’s deep snowpack, which exceeded 150 percent of normal. Snowmelt has also contributed to high water levels in reservoirs upstream of Osoyoos Lake including Okanagan...