USGS Water-Year Summary 2024
12436000 FRANKLIN D. ROOSEVELT LAKE AT GRAND COULEE DAM, WA
LOCATION - Lat 47°57'20", long 118°59'02" referenced to North American Datum of 1927, in sec.01, T.28 N., R.30 E., Grant County, WA, Hydrologic Unit 17020005, in block 12 of Grand Coulee Dam on Columbia River, and at mile 596.6.
DRAINAGE AREA - 74,700 mi².
REVISIONS HISTORY - WSP 1286: 1942, 1945(M). WSP 1316: 1942 (May monthend contents). WSP 1933: Drainage area. WDR WA-73-1: 1965, 1967. WDR WA-75-1: 1974 monthend contents.
SURFACE-WATER RECORDS
PERIOD OF RECORD - April 1938 to current year. Prior to October 1943, published as Columbia River Reservoir at Grand Coulee Dam.
GAGE - U.S. Geological Survey water-stage recorder. Datum of gage is NGVD of 1929, adjustment of 1937 (Bureau of Reclamation datum), or 1.425 ft above NGVD of 1929 (levels by Bureau of Reclamation). Prior to Apr. 24, 1942, nonrecording gage at site 2,000 ft upstream at same datum.
EXTREMES FOR PERIOD OF RECORD - Maximum contents 9,586,000 acre-ft, July 17, 1942, June 3, 1945, elevation, 1,290.3 ft; maximum elevation, 1,290.36 ft, Aug. 6, 1976; minimum contents observed, 16,200 acre-ft, Aug. 29, 1938, elevation, 956.1 ft.