Osoyoos Lake & Surrounding Water Levels

The Cottages Are Not Exempt from Flooding

Although ‘The Cottages’ are set primarily in a desert landscape, we are not exempt from the adverse effects of water level change.  We are located at the south end of the Okanagan River valley, and on occasion, both the lake and the local river levels are subject to rapid rise.  This occurs especially when the weather changes in the surrounding mountains during Spring run-off.

Such an event occurred in 2018, resulting in extensive flooding at our marina, beachfront, and in the surrounding areas along the Channel; both north and south of us.

The water levels of Osoyoos Lake are closely monitored and tracked by the U.S. Geological Survey.  This data is readily available for public viewing at the link below:

Osoyoos Lake Levels

Flood Watch

OSOYOOS LAKE levels, taken at the Zosel Dam in OROVILLE WA., by

U.S. Geological Survey

Historic Levels of note:

  • 1894 – 918.80 ft.
  • 1948 – 916.74 ft.
  • 1972 – 917.06 ft.
  • 2018 – 916.45 ft.

Typical Summer Levels are approximately 912.00  ft.

The minimum elevation of structures built at The Cottages is 922 ft., which is nearly 4 ft. above the maximum height of the 200 yr. flood plain level

Ground level altitude @ ‘The Clubhouse’ is 934 ft. 

The Zosel Dam is used by the Washington Department of Ecology to regulate the water level in Osoyoos Lake.  When spring runoff swells, the Similkameen River is forced to  back up into the Okanagan River from the point where the two rivers join, at their confluence just south of Oroville.  This causes the Okanogan to rise to a point where the dam can no longer control the flow, and it reverses northward.

Lake Osoyoos is fed by Okanagan Lake to the north, and lake levels are regulated by the Zosel Dam situated on the Okanogan River in Oroville to the south.  Making room for the extra volume of water produced by rapid snow melt in the upper watershed, puts pressure on Lake Osoyoos.

In addition, water can back up to Zosel Dam where the much larger Similkameen River joins the Okanogan River.  This makes it difficult to rapidily release water from Osoyoos Lake at the dam, resulting in flooding.


Osoyoos Lake Water Levels


Emergency Procedures Committee