USGS Water-Year Summary 2023
08105700 San Gabriel River at Laneport, TX
LOCATION - Lat 30°41'39", long 97°16'43" referenced to North American Datum of 1927, Williamson County, TX, Hydrologic Unit 12070205, on right bank at upstream side of county bridge, 0.2 mi north of Laneport, 3.4 mi downstream from Willis Creek, 7.5 mi northwest of Thrall, and 26.2 mi upstream from mouth.
DRAINAGE AREA - 738 mi².
REVISIONS HISTORY - WRD TX-74-1: 1965(M), 1966(P), 1967(M), 1968, 1969(P), 1973(P). WDR TX-76-2: Drainage area.
SURFACE-WATER RECORDS
PERIOD OF RECORD - July 1965 to current year.
PERIOD OF RECORD, Water-Quality.--
CHEMICAL DATA: July 1972 to Aug. 1989, Oct. 1999 to Sept. 2001.
BIOCHEMICAL DATA: July 1972 to Aug. 1989.
PERIOD OF DAILY RECORD, Water-Quality.--
WATER TEMPERATURE: Dec. 1976 to Mar. 1982.
GAGE - Water-stage recorder. Datum of gage is 412.60 ft above NGVD of 1929. Satellite telemeter at station.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum stage since 1910, 39.6 ft, occurred Sept. 1921. Other significant floods occurred Apr. 1957, 34.6 ft; and Oct. 1959, 33.8 ft; from floodmarks at present site and datum (discharges not determined).
EXTREMES FOR PERIOD PRIOR TO REGULATION -
WATER YEARS, 1965-1979: Maximum discharge, 31,200 ft³/s Oct. 31, 1974 (gage height, 30.80 ft); minimum daily, 0.28 ft³/s Aug. 25-28, 1978.
AVERAGE DISCHARGE FOR PERIOD PRIOR TO REGULATION - 14 years (water years 1966-79), 289 ft³/s (209,400 acre-ft/yr).