USGS Water-Year Summary 2024
11274790 Tuolumne River at Grand Canyon of Tuolumne, above Hetch Hetchy, CA
LOCATION - Lat 37°55'00", long 119°39'32" referenced to North American Datum of 1927, Tuolumne County, CA, Hydrologic Unit 18040009, in Yosemite National Park, on right bank, 7.8 mi southeast of O'Shaughnessy Dam at Hetch Hetchy, and 3.4 mi north of White Wolf.
DRAINAGE AREA - 301 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 2006 to current year.
GAGE - Water-stage recorder, crest-stage gage since Oct. 12, 2006. Datum of gage is 3,813.65 ft above NAVD of 1988.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 7,060 ft³/s, June 8, 2010, gage height, 20.83 ft; minimum discharge, 4.1 ft³/s, Jan. 17, 2012, gage height, 6.57 ft.
WATER-QUALITY RECORDS
PERIOD OF RECORD -
DISCRETE WATER-QUALITY DATA:
CHEMICAL DATA: Water years 2015-16.
CONTINUOUS WATER-QUALITY DATA:
SPECIFIC CONDUCTANCE: Water years October 2007 to current year. (water years 2008-2023, daily).
WATER TEMPERATURE: Water years October 2006 to current year. (water years 2007-2023, daily).
TURBIDITY: Water years October 2006 to current year. (water years 2007-2023, daily).
INSTRUMENTATION - Water quality monitor since October 2006.