USGS Water-Year Summary 2021
11073300 San Antonio Creek at Riverside Drive, near Chino, CA
LOCATION - Lat 34°01'07", long 117°43'47" referenced to North American Datum of 1927, San Bernardino County, CA, Hydrologic Unit 18070203, in Santa Ana del Chino Grant, on right bank, at south end of Riverside Drive Bridge, 0.4 mi upstream from confluence with Chino Creek, 2.4 mi northwest of Chino, and 10.2 mi downstream from San Antonio Dam.
DRAINAGE AREA - 36.6 mi².
PERIOD OF RECORD - December 1998 to current year.
GAGE - Water-stage recorder and concrete-lined flood-control channel. Elevation of gage is 735 ft above NGVD of 1929, from topographic map.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 3,420 ft³/s, Oct. 20, 2004, gage height, 5.43 ft, from rating curve extended above 576 ft³/s, on basis of step-backwater analysis; no flow at times in most years.