The International Joint Commission has issued an Order of Approval renewing the State of Washington’s authority to operate Zosel Dam and making minor modifications in how water levels on Osoyoos Lake will be managed.
The dam, located in Oroville, Wash., is subject to international jurisdiction because it regulates the outflow from Osoyoos Lake, and backs water across the border into British Columbia, including the Okanagan Valley watershed.
“Thanks to the active participation in the process by watershed residents and input from the state and province, the IJC was able to thoroughly vet the issues affecting both countries before revising this order,” said IJC Commissioner Lyall Knott.
“As we move forward, we will continue to engage stakeholders in the watershed, and keep them advised of the reservoir operations and water levels. Cooperation is an ongoing process,” added IJC commissioner Rich Moy.
One of the groups contributed research and scientific information to that discussion was the Okanagan Basin Water Board.
“I think most of the things we wanted to see in the Order have happened,” said Anna Warwick Sears, executive director of the OBWB.
“There were no surprises…there was no guaranteed flow on the American side at our expense, acknowledgement of the need to protect our fisheries…”
The current Orders for Zosel Dam were scheduled to expire in February and April 2013. The renewal process began in 2000 with the scoping of issues related to water levels, future water supplies and water quality in order to develop a plan of study.
A number of these issues had been raised at the annual public meetings of the International Osoyoos Lake Board of Control, which was appointed by the IJC to oversee implementation of its Orders. The IJC launched eight studies in 2006 and these were completed in 2011.
Stakeholders also held in-depth discussions of watershed issues at the Osoyoos Lake Water Science Forums held in September 2007 and September 2011.
In a June 2012 report to the IJC, the board concluded that the current Orders have adequately facilitated control of water levels in Osoyoos Lake, to the extent possible, primarily for the benefit of agriculture, tourism, municipal interests and fisheries protection.
The IJC held public hearings in Oroville, Washington and Osoyoos on July 24 and 25, 2012, respectively, and met with the Osoyoos Indian Band on July 25, 2012. Several shoreline residents in Canada voiced the view that a sustained maximum lake level of 912.5 feet would be too high because of concerns about flooding, erosion, riparian habitat, endangered species and navigation.
The IJC Commissioners heard these concerns and, after due consideration and consultation with the Board, made adjustments to the rule curve recommended by the board in their June 2012 report. The commissioners decided that the rule curve would include a one foot-range with a 912-foot maximum in the summer under normal conditions, and a two-foot range with a 912.5-foot maximum during drought years.
The IJC was established under the Boundary Waters Treaty of 1909 to help Canada and the United States prevent and resolve disputes over the waters they share.
One of the IJC’s main responsibilities is to approve projects that affect the natural water levels and flows on the other side of the international boundary.