USGS Water-Year Summary 2020
08177700 Olmos Creek at Dresden Drive, San Antonio, TX
LOCATION - Lat 29°29'56", long 98°30'36" referenced to North American Datum of 1927, Bexar County, TX, Hydrologic Unit 12100301, on right bank 30 ft downstream from low-water bridge on Dresden Drive at San Antonio, 0.15 mi west of intersection of Blanco Road and Dresden Drive, and 4.0 mi upstream from Olmos Dam.
DRAINAGE AREA - 21.2 mi².
PERIOD OF RECORD - June 1968 to Sept. 1981 (daily mean discharge), Oct. 1982 to July 2001 (peak discharges greater than base discharge), Aug. 2001 to current year.
PERIOD OF RECORD, Water-Quality.--
CHEMICAL DATA: Nov. 1968 to Apr. 1995, Oct. 1997 to June 1999.
BIOCHEMICAL DATA: Nov. 1968 to Apr. 1995, Oct. 1997 to June 1999.
PESTICIDE DATA: Nov. 1968 to Apr. 1995, Oct. 1997 to June 1999.
SEDIMENT DATA: Oct. 1972 to Sept. 1973.
GAGE - Water-stage recorder. Datum of gage is 720.00 ft above NGVD of 1929. Satellite telemeter at station.
EXTREMES OUTSIDE PERIOD OF RECORD - Floods in Sept. and Nov. 1947 reached a stage of 8.5 ft, from information by local resident.
PERIOD OF RECORD - Nov. 2009 to current year
INSTRUMENTATION - Unshielded tipping bucket rain gage with 8-inch diameter collector ring, with satellite telemetry. Datum of gage is 720.00 ft above NGVD of 1929.