USGS Water-Year Summary 2024

11134000 Santa Ynez River at H Street, near Lompoc, CA

LOCATION - Lat 34°40'06", long 120°27'25" referenced to North American Datum of 1927, Santa Barbara County, CA, Hydrologic Unit 18060010,  in Lompoc Grant, near right bank, 1,200 ft downstream of H Street Bridge on State Highway 1, and 2 mi north of Lompoc.

DRAINAGE AREA - 815 mi².

SURFACE-WATER RECORDS

PERIOD OF RECORD - October 1946 to September 1962, October 1998 to current year.

GAGE - Water-stage recorder. Datum of gage is 60.60 ft above NAVD of 1988. Various datums used during period of record. May 5, 2000, to July 25, 2002, 1,000 ft downstream on left bank at different datum. July 25, 2002, to May 14, 2009, auxiliary water-stage recorder relocated at site 200 ft downstream on left bank at same datum.

REMARKS - Flow regulated by Jameson Lake, Gibraltar Reservoir, and since November 1952, by Lake Cachuma (stations 11121000, 11122000, and 11125500, respectively). Water diverted out of Jameson Lake, Gibraltar Reservoir, and Lake Cachuma to cities of Montecito, Santa Barbara, and Goleta for municipal supply. Water pumped from wells along banks of river for irrigation in valley upstream. Satellite telemeter at station. See schematic diagram of Santa Ynez River Basin available from the California Water Science Center.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge prior to regulation by Lake Cachuma, 37,900 ft³/s, Jan. 16, 1952, gage height, 17.4 ft (datum then in use), from rating curve extended above 2,900 ft³/s. Maximum discharge after regulation by Lake Cachuma, 41,600 ft³/s, Mar. 6, 2001, gage height, 14.09 ft; no flow for several months in each year.