USGS Water-Year Summary 2024
12105800 HOWARD A. HANSON RESERVOIR NEAR PALMER, WA
LOCATION - Lat 47°16'38", long 121°47'03" referenced to North American Datum of 1927, in NW 1/4 NW 1/4 sec.28, T.21 N., R.8 E., King County, WA, Hydrologic Unit 17110013, near left bank on outlet gate structure, just upstream from Howard A. Hanson Dam on Green River, 1.4 mi upstream from Bear Creek, 5.1 mi southeast of Palmer, and at mile 64.5.
DRAINAGE AREA - 220 mi².
REVISIONS HISTORY - WDR WA-96-1: 1985-1995 maximum and minimum contents.
SURFACE-WATER RECORDS
PERIOD OF RECORD - December 1961 to current year.
GAGE - Water-stage recorder. Prior to Oct. 1, 1999, non-recording gage at same site and datum. Datum of gage is NGVD of 1929, supplementary adjustment of 1947.
COOPERATION - Elevations and capacity table furnished by Corps of Engineers.
EXTREMES FOR PERIOD OF RECORD - Maximum contents observed, 78,759 acre-ft, Jan. 9, 2009, elevation, 1,189.2 ft; minimum contents observed, 34 acre-ft, Nov. 2, 1962, elevation, 1,037.6 ft (capacity table then in use).