INTERNATIONAL OSOYOOS LAKE BOARD OF CONTROL
ANNUAL REPORT
for
CALENDAR YEAR 2003

The International Osoyoos Lake Board of Control was established on February 12, 1986, by the International Joint Commission (IJC) to carry out the provisions of the Commission's Order of Approval dated December 9, 1982, and the Supplementary Order of Approval dated October 17, 1985.

ACTIVITIES OF THE BOARD

On April 8, 2003, the Board notified the Washington State Department of Ecology in writing that based on snowmelt forecasts, drought conditions for operating Osoyoos Lake would be invoked in 2003 and summer lake levels would be managed between 910.5 and 913.0 feet (277.52 and 278.28 meters) per the Order. A notice of the drought declaration (shown below) was published in local newspapers on both sides of the International Border and was posted on the Board’s public Web page. The Board received no public complaints about the 2003 lake levels.

NOTICE OF OSOYOOS LAKE
DROUGHT YEAR OPERATION

The U.S. National Weather Service’s April 8, 2003 forecast of volume of flow in the Similkameen River at Nighthawk, Washington, for April through July 2003 is 950,000 acre-feet. This forecast meets the criteria for a drought-year declaration for Osoyoos Lake as specified in Condition 8a of the International Joint Commission Order of Approval dated December 9, 1982. Between April 1, 2003, and October 31, 2003, the State of Washington is required to maintain a lake elevation of at least 910.5 feet USCGS (U.S. Coast and Geodetic Survey), and may raise Osoyoos Lake to a maximum elevation of 913.0 feet USCGS. This drought declaration will be rescinded before October 31 if hydrologic conditions change such that none of the drought criteria specified in Condition 8 continue to be met.

International Osoyoos Lake Board of Control
April 8, 2003

For additional information contact:
In Canada: Mr. Daniel Millar, (604) 664-9345
In the United States: Mr. Robert Kimbrough, (253) 428-3600 x 2608
http://wa.water.usgs.gov/IJC/Osoyoos/osoy.homepage.html

During drought conditions the maximum allowable level of Osoyoos Lake from April through October is increased from 911.5 to 913.0 feet (277.82 to 278.28 meters) to allow for additional water storage. On May 5, 2003, the State of Washington and Province of British Columbia reached an informal agreement to transfer the top one-half foot of Osoyoos Lake drought storage to Okanagan Lake and/or Skaha Lake (located upstream), thereby limiting the maximum level on Osoyoos Lake to 912.5 feet (278.13 meters) for the duration of the drought period. This top half foot (912.5-913.0 feet) (0.15 meter between 278.13 and 278.28 meters) may negatively impact tourism and groundwater, and may encroach on properties surrounding the lake.

Also on April 8, 2003, the Board participated in a video teleconference with the IJC. The Board presented a brief overview of Osoyoos Lake, Zosel Dam, and the Osoyoos Lake Orders of Approval, which have an expiry date of 2013. In a discussion of the Orders renewal process, the Board briefly reviewed the type of studies that may be needed prior to renewal, and the key steps of a renewal work plan.

A formal meeting of the Board was held on September 9, 2003, in Osoyoos, B.C. Topics of discussion included channel capacity below Osoyoos Lake, the re-issuance of the Osoyoos Orders of Approval, and hydrologic conditions and compliance with the Orders in 2003.

A public meeting was held in the evening following the Board meeting. Board members gave presentations on the IJC and Osoyoos Lake Board of Control, hydrologic conditions and management of lake levels in 2003, and the Orders renewal process. The presentation on Orders renewal summarized the basic components of the renewal process, including: identifying the applicant; developing a draft Plan of Study; obtaining input from the public; finalizing the Plan of Study; conducting studies; holding Commission consultations; and renewing or approving a new Order. Following the presentation, members of the public suggested additional issues that might be considered in the renewal process, including the timing and range of lake level fluctuations, and the link between lake levels and water quality, irrigation, recreation, and fisheries.

OSOYOOS LAKE LEVELS IN 2003

Throughout any given year, the level of Osoyoos Lake may fluctuate in accordance with criteria outlined in the IJC’s Order of Approval dated December 9, 1982. Lake levels are influenced naturally by discharge in the Okanagan and Similkameen Rivers and by the operation of Zosel Dam situated at the outlet of the lake. The Oroville-Tonasket Irrigation District operates Zosel Dam under authority from the State of Washington, Department of Ecology.

The blue area in figure 1 shows the authorized range of normal operating elevations, 909.0 to 911.5 feet (277.06 to 277.83 meters). The area contained within the dotted line in figure 1 shows the authorized range of elevations, 910.5 to 913.0 feet (277.52 to 278.28 meters) that may be used to manage storage from April 1 to October 31 if at least one of the drought criterion described in Condition 8 of the Order are declared in effect by the Board. Condition 9 of the Order recognizes that backwater from high flow in the Similkameen River and (or) excessive flow in the Okanagan River may cause Osoyoos Lake levels to rise above the authorized range.

During 2003, all three drought criteria set forth in Condition 8 of the Order of Approval were met (table 1). As a result, lake levels were maintained in the authorized range of 910.5 to 913.0 feet (277.52 to 278.28 meters) from April 1 to October 31.

The maximum instantaneous elevation on Osoyoos Lake of 912.95 ft (278.27 meters) occurred on May 2 and 3, 2003. The maximum daily-mean elevation of 912.92 ft (278.26 meters) occurred on May 2 and 3 (figure 1). Lake elevations greater than 912.5 (258.13 meters) in late April and early May occurred prior to the arrangement between Washington and British Columbia that limited the maximum water level to 912.5 feet for the remainder of the drought period. High river discharges and stages created backwater conditions in the Okanogan River downstream from Osoyoos Lake for 22 days in 2003; however, the backwater conditions did not cause lake levels to rise above the authorized range in 2003. (Backwater conditions did cause lake elevations above the authorized range in May and June 2002).

Figure 1. Osoyoos Lake Elevations, in accordance with IJC Order of Approval dated December 9, 1982, and Supplementary Order of Approval dated October 17, 1985.

The maximum instantaneous discharge of the Okanogan River at Oroville occurred on May 5 and was 1,330 cubic feet per second (37.67 cubic meters per second). Because a flow in excess of 2,500 cubic feet per second (70.80 cubic meters per second) was not observed this year, the capacity of the outlet channel was not verified in accordance with Condition 3 of the 1985 Order. Data on Osoyoos Lake elevation and relevant river flows are summarized in appendix 1 and depicted in figures 2 and 3.

Figure 2. Hydrograph of Osoyoos Lake elevation.

Figure 3. Hydrographs of discharge for the Similkameen and Okanogan (Okanagan in Canada) Rivers.

 

APPENDIX I.-OSOYOOS LAKE LEVELS, INFLOWS, AND OUTFLOWS [cubic feet per second, cfs; cubic meters per second, cms]

International Osoyoos Lake Board of Control Membership
Canadian Membership	U.S. Membership
Kirk Johnstone Chair, Canadian Section Manager, Aquatic & Atmospheric Sciences Environment Canada 201 – 401 Burrard Street Vancouver, British Columbia V6C 3S5 Phone: (604) 664-9120 Fax: (604) 664-9126 Email: Kirk.Johnstone@ec.gc.ca	Cindi Barton Chair, United States Section Director, Washington Water Science Center U.S. Geological Survey 1201 Pacific Avenue, Suite 600 Tacoma, Washington 98402-4300 Phone: (253) 428-3600 x 2602 Fax: (253) 428-3614 Email: cbarton@usgs.gov
James Mattison Executive Director, Strategic Initiatives Div. Land and Water British Columbia Inc. P.O. Box 9475 STN PROV GOVT V8W 9W6 5th Floor – 609 Broughton Street Victoria, British Columbia Phone: (250) 387-1649 Fax: (250) 952-6237 Email: Jim.Mattison@gems7.gov.bc.ca	Colonel Debra M. Lewis District Engineer Seattle District U.S. Army Corps of Engineers P.O. Box 3755 Seattle, Washington 98124-3755 Phone: (206) 764-3690 Fax: (206) 746-6544 Email: Debra.Lewis.COL@nws02.usace.army.mil
Brian Symonds Head, Flood Hazard Management Ministry of Water, Land and Air Protection 102 Industrial Place Penticton, British Columbia V2A 7C8 Phone: (250) 490-8255 Fax: (250) 490-2231	Kris Kauffman Civil Engineer 12228 Nyanza Road SW. Lakewood, Washington 98499-1444 Phone: (253) 581-9752 – Message Email: waterrightsinc@msn.com
Daniel Millar Secretary, Canadian Section Environment Canada 201 – 401 Burrard Street Vancouver, British Columbia V6C 3S5 Phone: (604) 664-9345 Fax: (604) 664-9126 Email: Daniel.Millar@ec.gc.ca	Robert Kimbrough Secretary, U.S. Section Assistant Director for Hydrologic Data Washington Water Science Center U.S. Geological Survey 1201 Pacific Avenue, Suite 600 Tacoma, Washington 98402-4300 Phone: (253) 428-3600 x 2608 Fax: (253) 428-3614 Email: rakimbro@usgs.gov