USGS Water-Year Summary 2024

11450000 Clear Lake at Lakeport, CA

LOCATION - Lat 39°02'21", long 122°54'44" referenced to North American Datum of 1927, in NE 1/4 NE 1/4 sec.25, T.14 N., R.10 W., Lake County, CA, Hydrologic Unit 18020116, on private pier behind Mosquito Abatement District, 410 Esplanade Street, in Lakeport.

RELOCATED:  Rapid Deployment Gage mounted to steel railing at the end of the Library Park Pier on October 7, 2021 due to drought and low lake level.

DRAINAGE AREA - 528 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD - 1874-1900 (incomplete), January 1913 to April 1982, October 1984 to current year.

GAGE - Water-stage recorder. Datum of gage is 1,320.74 ft above NAVD of 1988 and 1,318.26 ft above NGVD of 1929. Prior to July 8, 1947, nonrecording gage, and July 8, 1947, to Mar. 17, 1949, at municipal wharf at foot of Third Street in Lakeport at datum 0.33 ft higher. Mar. 18, 1949, to Sept. 30, 1967, at private pier at foot of Fourth Street at datum 0.33 ft higher. Gage relocated at same datum, Apr. 20, 1982, and published as "at Clearlake" for 1982-84.

REMARKS - This natural lake is regulated by gates on a dam at outlet, completed in 1915. Capacity between gage heights 0.00 and 7.56 ft, limits stipulated by court decree of 1920, about 319,000 acre-ft. Water is released down natural channel of Cache Creek (station 11451000), from which it is diverted for irrigation. See schematic diagram of lower Sacramento River Basin available from the California Water Science Center.

EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Mar. 4, 1983, reached a stage of 11.24 ft, present datum, from floodmarks.

EXTREMES FOR PERIOD OF RECORD - Maximum gage height, 11.44 ft, Feb. 24, 1998, minimum observed, -3.50 ft, Sept. 24-27, 1920.