Board looks to ease transition of levels for Osoyoos Lake

Osoyoos Lake’s level is maintained within a narrow range dictated by an international agreement that expires in February 2013

Splitting up $25,000 for conservation efforts on both sides of Osoyoos Lake’s international boundary was easy, but it remains to be seen if a rewrite of the management agreement will be equally smooth sailing.

Osoyoos Lake’s level is maintained within a narrow range dictated by an international agreement that expires in February 2013.

The so-called operating orders specify the level be kept at between 911 and 911.5 feet above sea level between April 1 and Oct. 31, and between 909 and 911.5 feet from Nov. 1 to March 31. During drought conditions, however, the lake may be raised to 913 feet in order to store water.

Those prescribed levels are maintained by the Zosel Dam, which lies about three kilometres downstream from the southern edge of Osoyoos Lake and is operated by the Oroville-Tonasket Irrigation District.

With the orders set to expire in about seven months, the International Osoyoos Lake Board of Control has asked for public input and recommendations on the new agreement.

The Okanagan Basin Water Board has a few ideas.

Key for executive director Anna Warwick Sears is a smoothing out of the transition between lake levels during seasonal changes.

“The way that it is, keeping it low for an extended period of time and then having to rapidly increase it, that becomes problematic when you’re managing for fish flows downstream and things like that,” she said. “Also it’s a hassle for the residents, and they don’t like it.”

The water board had a consultant study the operating orders to help prepare its submission to the international body. The consultants recommended a new eight-week window to raise and lower the lake level, to help mitigate impacts on wildlife, residents and shorelines.

Warwick Sears called it “an easy-to-implement approach that won’t cost anybody any money.”

Her other big issue is protecting fish. When water flows below the dam are reduced, it makes passage difficult for salmon returning to spawn. Warwick Sears said guaranteed flow rates will probably be a non-starter, but other steps, such as new fish channels, could also work.

The international board, made up of four government bureaucrats from each side of the border, is expected to release its preliminary recommendations later this month. Two public forums are tentatively scheduled for late July.

Some of the issues were already aired last September at the Osoyoos Lake Science Forum. That event also generated a $25,000 surplus, which its steering committee voted to distribute equally across the border. The Town of Osoyoos will administer the $12,500 on the Canadian side, while the Lake Osoyoos Association will handle the cash in the U.S.

Warwick Sears said the money is intended to fund shoreline restoration and water quality projects.