USGS Water-Year Summary 2021
11467510 South Fork Gualala River near The Sea Ranch, CA
LOCATION - Lat 38°42'33", long 123°25'32" referenced to North American Datum of 1927, Sonoma County, CA, Hydrologic Unit 18010109, in German Grant, on left bank, 0.8 mi downstream of Wheatfield Fork Gualala River, and 2.0 mi north of The Sea Ranch.
DRAINAGE AREA - 161 mi².
PERIOD OF RECORD - June 1991 to September 1992 (low flow only) and October 2007 to current year.
GAGE - Water-stage recorder. Elevation of gage is 40.0 ft above NGVD of 1929, from levels.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Dec. 22, 1955, reached a stage of 24.57 ft, former site and datum, South Fork Gualala River near Annapolis (station 11467500), from slope-area measurement, discharge 55,000 ft³/s.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 35,700 ft³/s, Feb. 27, 2019, gage height 35.67 ft. No flow for many days during water year 2008, and Oct. 1, 2, 2008.