USGS Water-Year Summary 2023
11323500 Mokelumne River below Camanche Dam, CA
LOCATION - Lat 38°13'34", long 121°01'24" referenced to North American Datum of 1983, in NE 1/4 SE 1/4 sec.06, T.4 N., R.9 E., San Joaquin County, CA, Hydrologic Unit 18040012, at foot of Camanche Dam, 0.35 mi upstream from Murphy Creek, and 4.3 mi northeast of Clements.
DRAINAGE AREA - 621 mi².
REVISIONS HISTORY - WSP 751: Drainage area. WSP 881: 1905-09 (yearly summaries only). WSP 1445: 1911, 1917 (instantaneous maximum discharge), 1925 (instantaneous maximum discharge). WDR CA-94-3: 1993 (instantaneous maximum discharge).
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1904 to current year. Monthly discharge only for some periods, published in WSP 1315-A and 1735. Prior to October 1961, published as "near Clements."
CHEMICAL DATA: Water years 1906-07, 1965-66. Published as "at Clements" in 1906-07.
WATER TEMPERATURE: Water years 1962-68, 1970-76.
SEDIMENT DATA: Water years 1956-70. Prior to 1962 water year, published as "near Clements".
GAGE - A series of ultrasonic flowmeters located within Camanche Reservoir at three outlet pipes becomes primary record for releases beginning October 2008. The summation of discharge from these flowmeters plus the record of spill (when it occurs) make up the total release below Camanche Reservoir. Elevation of ultrasonic flowmeters is 115.50 ft above NGVD of 1929 (provided by East Bay Municipal Utility District). Elevation of spillway gage is 235.50 ft above NGVD of 1929 (levels by East Bay Municipal Utility District). If necessary, the gage, previously published as Mokelumne River below Camanche Dam (located 1.0 mi downstream) becomes auxiliary gage for discharge determination. Auxiliary gage is water-stage recorder. Elevation of auxiliary gage is 82.71 ft above NGVD of 1929 (levels by East Bay Municipal Utility District). October 1999 to September 2001, and October 2002 to September 2003, published data from ultrasonic flowmeters on outlet pipes at Camanche Dam and water-stage recorder on spillway. See WSP 1930 for history of changes prior to Oct. 1, 1961.
COOPERATION - Records were collected by East Bay Municipal Utility District, under general supervision of the U.S. Geological Survey, in connection with Federal Energy Regulatory Commission project no. 2916.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 28,800 ft³/s, Nov. 21, 1950, gage height, 24.40 ft, site and datum then in use; no flow on several days in 1924.
Maximum discharge since construction of Camanche Dam in 1963, 6,060 ft³/s, Feb. 19, 1986, gage height, 11.21 ft; minimum daily, 23 ft³/s, Oct. 6, 1977.