Operations at Zosel Dam in Oroville switch to spring mode

OROVILLE – Operators at Zosel Dam are slowly increasing the water level of Lake Osoyoos from winter to spring operating elevations to manage snowmelt. The lake will gradually gain about two feet between now and early May.

Residents on the lake, which straddles the U.S. and Canadian border near Oroville, may notice some fluctuations during that time period. Operations in Canada impact flows up or down as well. Adjustments are made regularly at Zosel to account for those temporary changes in flows.

Gary DeVon/G-T file photo The state Department of Ecology regulates lake levels at Zosel Dam in Oroville. Lake levels can fluctuate into early July depending on snowpack. Ecology seeks to maintain the water level between 911.5 and 912 feet from May 1 to Sept. 15, but occasionally there’s a chance for flooding when snowmelt and runoff are high.

Gary DeVon/G-T file photo
The state Department of Ecology regulates lake levels at Zosel Dam in Oroville. Lake levels can fluctuate into early July depending on snowpack. Ecology seeks to maintain the water level between 911.5 and 912 feet from May 1 to Sept. 15, but occasionally there’s a chance for flooding when snowmelt and runoff are high.

In addition, snow melt may cause the Okanogan and Similkameen rivers to rise, causing a “back up” that raises the level of Lake Osoyoos sharply.

“These spring runoff events are to be expected and they don’t usually last too long,” explained Al Josephy, with the Washington Department of Ecology, which operates Zosel Dam. “During these periods the gates at the dam are kept wide open and the river and lake react based on the natural flow of the river”

Osoyoos Lake levels are mandated by the International Joint Commission, a board made up of representatives from the U.S. and Canada. More information on the International Osoyoos Lake Board of Control and the new Order of Approval can be found athttp://ijc.org/boards/iolbc/.

To track the progress of lake levels in “real-time,” as well as find additional information, go to the U.S. Geological Survey web page for Osoyoos Lake.