of the Sixtieth Annual Report
The instantaneous maximum discharge of the Columbia River at the international boundary was 3,480 cubic meters per second (123,000 cubic feet per second) on May 25, about 54 percent below the mean annual flood for the 64-year period of record, and ranking sixty-third out of sixty-three peaks for the same period. The floods of 1979 and 1995 were equal.
Instantaneous extremes of stage on Franklin D. Roosevelt Lake varied between elevations 392.442 meters (1,287.54 feet) on December 17 and 370.923 meters (1,216.94 feet) on April 19. The stage was 391.406 meters (1,284.14 feet) at midnight on December 31, 2001. Backwater at the international boundary varied during the year between 0.000 meter (0.00 feet) and 0.140 meter (0.46 feet). Backwater on December 31, 2001, was 0.046 meter (0.15 feet). Flashboards at Grand Coulee Dam were in place for all of 2001 and should remain in place in the future under normal conditions.
From: The International Columbia River Board of Control
(1) The Order of the International Joint Commission dated December 15, 1941, in the matter of the Application of the United States for Approval of the construction and operation of the Grand Coulee Dam and reservoir (Franklin D. Roosevelt Lake),
|provided for the creation of an engineering board to be known as the International Columbia River Board of Control, to which the undersigned have been duly appointed. The order provides that the Board shall conduct studies under the supervision of the Commission as to the effect of the operation of Grand Coulee Dam and Franklin D. Roosevelt Lake upon water levels at and above the international boundary, and shall submit a report to the Commission annually.|
(4) The analyses of data collected indicate that backwater at the international boundary varied during the year between 0.000 meter (0.00 feet) and 0.140 meter (0.46 feet). Backwater on December 31, 2001, was 0.046 meter (0.15 feet). Backwater that occurred at the international boundary during the period January 1, 1997, to December 31, 2001, as computed at 10-day intervals each month, is plotted on the accompanying graph. Backwater since the time of filling of Franklin D. Roosevelt Lake in June 1942 to December 31, 1996, is plotted on the charts submitted with previous annual reports.
(5) The Board has been informed by the United States Bureau of Reclamation that flashboards at Grand Coulee Dam were in place for all of 2001.
Kirk E. Johnstone, Manager
Aquatic and Atmospheric Sciences Division
Pacific & Yukon Region
Vancouver, British Columbia
Member, Canadian Section
Cynthia Barton, District Chief
Water Resources Division
United States Geological Survey
Member, U.S. Section