USGS Water-Year Summary 2021
11044300 Santa Margarita River at Fallbrook Public Utility District Sump, near Fallbrook, CA
LOCATION - Lat 33°24'49", long 117°14'25" referenced to North American Datum of 1927, in NW 1/4 NW 1/4 sec.07, T.9 S., R.4 W., San Diego County, CA, Hydrologic Unit 18070302, on left bank, 0.3 mi upstream from confluence with Sandia Creek, and 2.9 mi north of Fallbrook.
DRAINAGE AREA - 620 mi².
PERIOD OF RECORD - October 1989 to current year.
DISSOLVED OXYGEN: Water years 2000-03.
pH: Water years 2000-03.
SPECIFIC CONDUCTANCE: Water years 2000-03.
WATER TEMPERATURE: Water years 2000-03.
GAGE - Water-stage recorder and crest-stage gage. Elevation of gage is 330 ft above NGVD of 1929, from topographic map.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 34,000 ft³/s, estimated, based on regression equation and flood routing of upstream flows, Jan. 16, 1993, gage height, 15.89 ft; no flow several days in 1990.