USGS Water-Year Summary 2021
11162570 San Gregorio Creek at San Gregorio, CA
LOCATION - Lat 37°19'33", long 122°23'08" referenced to North American Datum of 1927, San Mateo County, CA, Hydrologic Unit 18050006, in San Gregorio Grant, on right bank, at downstream side of bridge on Stage Road (Old Coast Highway), 0.1 mi south of town of San Gregorio, and 1.4 mi upstream from mouth.
DRAINAGE AREA - 50.9 mi².
PERIOD OF RECORD - October 1969 to September 1994, May 2001 to September 2005, July 2007 to current year.
SEDIMENT DATA: Water years 1986, 1990-1993.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 11.40 ft above NGVD of 1929.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of Dec. 22, 1955, reached a stage of 15.60 ft, from floodmarks, discharge, 3,620 ft³/s, based on contracted-opening measurement of peak flow.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 7,910 ft³/s, Jan. 4, 1982, gage height, 21.28 ft, from rating curve extended above 560 ft³/s, on basis of contracted-opening measurement of peak flow; no flow for many days in some years.