USGS Water-Year Summary 2020
08178050 San Antonio River at Mitchell Street, San Antonio, TX
LOCATION - Lat 29°23'34", long 98°29'40" referenced to North American Datum of 1927, Bexar County, TX, Hydrologic Unit 12100301, on left bank 15 ft upstream from Mitchell Street Bridge in San Antonio, 0.2 mi upstream from San Pedro Creek, and 228.7 mi upstream from mouth.
DRAINAGE AREA - 42.4 mi², At low-flow, flow of river comes from intermittent spring flow and from artesian wells.
PERIOD OF RECORD - Oct. 1992 to current year (see GAGE paragraph).
PERIOD OF RECORD, Water-Quality.--
CHEMICAL DATA: Dec. 1991 to June 1999.
BIOCHEMICAL DATA: Dec. 1991 to June 1999.
PESTICIDE DATA: Dec. 1991 to June 1999.
GAGE - Water-stage recorder and concrete control. Datum of gage is 585.07 ft above NGVD of 1929. Satellite telemeter at station. On Apr. 29, 2010, data collection was resumed after being suspended since Dec. 17, 2008 due to an extensive channel rectification project.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood of July 5, 1819, equaled or exceeded that of Sept. 10, 1921, from San Fernando Cathedral archives and old Spanish records.
PERIOD OF RECORD - Jul. 2010 to current year.
INSTRUMENTATION - Unshielded, standard 8-in. diameter, tipping-bucket raingage, mounted on the antenna mast 10 ft above land surface, with satellite telemtry. Datum of gage is 585.07 ft above NGVD of 1929.
EXTREMES FOR PERIOD OF RECORD - Maximum daily rainfall was 4.51 inches on October 24, 2015.