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transboundary watersheds

International Osoyoos Lake Board of Control Brian Symonds, P. Eng. Ministry of Water, Land and Air Protection & Member of IOLBC. Osoyoos Lake straddles the International Boundary between BC and Washington on the southward-flowing Okanagan River. transboundary watersheds.

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transboundary watersheds

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  1. International Osoyoos LakeBoard of ControlBrian Symonds, P. Eng.Ministry of Water, Land and Air Protection& Member of IOLBC

  2. Osoyoos Lake straddles the International Boundary between BC and Washington on the southward-flowing Okanagan River. transboundary watersheds

  3. Osoyoos Lake & Zosel Dam • Transboundary lake: 2/3 in Canada, 1/3 in USA • Normal lake levels are regulated by Zosel Dam in Oroville, Washington Zosel Dam • Lake levels subject to natural backwater • influence of Similkameen River during periods • of high flow

  4. History of Zosel Dam & IJC Involvement • 1927 - Zosel Dam constructed by Zosel Mill as a mill pond without reference to Canada or IJC • 1943 – First complaints to IJC regarding lake levels and influence of Zosel Dam • 1946 – IJC issues first Order regarding dam and discharge capacity • 1946 – IJC establishes International Osoyoos Lake Board of Control to monitor dam operations

  5. Original Zosel Dam

  6. History (cont.) • 1980 – Zosel Dam in disrepair and Washington applies to IJC to rebuild dam • 1982 – IJC issues Order of Approval for reconstruction of dam detailing capacity and allowable lake levels • 1985 – BC and Washington agree on MOU regarding cost sharing of design & construction • 1985 – IJC issues Supplementary Order authorizing new location & design • 1986/87 – Zosel Dam reconstructed

  7. New Zosel Dam

  8. IJC's 1982 and 1985 Orders allow Washington State to retain a range of lake levels essentially established in the Commission's 1946 Order of Approval, particularly for the benefit of agriculture, fish passage and recreation.

  9. OSOYOOS LAKE LEVELS Winter:909 to 911.5 ft. Summer:911 to 911.5 ft. Drought summers:910.5 to 913 feet(to aid irrigation). NormalConditions 2003 Prescribed lake levels may be exceeded by high Okanagan River flows or by backwater from Similkameen River. 2002

  10. The Orders provide three criteria for defining a drought year. These criteria may be either forecast or actual: • low flow on the Similkameen River • low inflows to Okanagan Lake • low levels on Okanagan Lake. Based on the Similkameen spring run-off forecast, drought conditions were declared in April 2003.

  11. Water level in this photo is 911.6 feet. Drought Condition Water Levels • During drought condition water levels maybe held at a maximum lake level of 913.0 feet. • Drought levels are a concern to Canadian lakeside residents since, as the lake approaches 912.5 or 913 feet, beaches and other shoreline areas become narrower, and allegedly may flood private property.

  12. Since 1992, BC and Washington have made informal arrangements that have enabled lake levels to be held below 912.5 ft during drought conditions. A similar informal arrangement was made in 2003

  13. OSOYOOS LAKE LEVELS Winter:909 to 911.5 ft. Summer:911 to 911.5 ft. Drought summers:910.5 to 913 feet(to aid irrigation). NormalConditions 2003 Prescribed lake levels may be exceeded by high Okanagan River flows or by backwater from Similkameen River. 2002

  14. The Osoyoos Order is one of the Commission’s few Orders that has an expiry date: 2013. “This approval will terminate: … (c) twenty-five (25) years after completion of construction, unless renewed.”

  15. Renewal of Orders - In 2002, the Board advised the IJC of the studies that may be needed prior to Order renewal (e.g. review of water level range & timing, drought criteria, outflow capacity, environmental concerns, etc.) and offered key steps of a renewal work plan. - In March 2003 the IJC responded requesting a dialogue with the Board on a the development of a Plan of Study for the renewal.

  16. For Canada: Kirk Johnstone (chair) Environment Canada Jim Mattison BC Ministry ofSustainable Resource Management Brian Symonds BC Ministry ofWater, Land and Air Protection Daniel Millar (sec.) For U.S.: Cindi Barton (chair) US Geological Survey Col. Ralph Graves US Army Corps of Engineers Kris Kauffman private consultant acting on behalf ofthe State of Washington Robert Kimbrough (sec.) The International Osoyoos Lake Board of Control Current membership…

  17. Websites International Joint Commission: http://www.ijc.org/ijcweb-e.html International Osoyoos Lake Board of Control: http://wa.water.usgs.gov/IJC/Osoyoos/ osoy.homepage.html

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