USGS Water-Year Summary 2017
11317000 Middle Fork Mokelumne River at West Point, CA
LOCATION - Lat 38°23'23", long 120°31'32" referenced to North American Datum of 1927, in SE 1/4 NE 1/4 sec.10, T.6 N., R.13 E., Calaveras County, CA, Hydrologic Unit 18040012, on right bank at highway bridge, 0.8 mi south of West Point, and 4.5 mi upstream from South Fork Mokelumne River.
DRAINAGE AREA - 68.4 mi².
PERIOD OF RECORD - October 1911 to current year. Monthly discharge only for October 1911, published in WSP 1315-A.
REVISED RECORDS - WSP 1515: 1919-20, 1927-28 (instantaneous maximum discharge), 1936 (instantaneous maximum discharge). WSP 1930: Drainage area.
GAGE - Water-stage recorder. Elevation of gage is 2,450 ft above NGVD of 1929, from topographic map. Prior to Oct. 6, 1926, nonrecording gage at site 1,200 ft upstream at different datum. Oct. 6, 1926, to Aug. 18, 1928, nonrecording gage at present site and datum.
COOPERATION - Records were collected by East Bay Municipal Utility District, under general supervision of the U.S. Geological Survey.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 5,040 ft³/s, Jan. 2, 1997, gage height, 9.28 ft, from rating curve extended above 4,010 ft³/s; no flow for many days in 1931 and Sept. 9, 1934.