USGS Water-Year Summary for Site 08105700

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	Available Parameters
	00060 Discharge(Max.,Min.,Mean)
	00065 Gage height(Mean)

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Water year 2023: 2022-10-01 to 2023-09-30

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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. Satellite telemetry at station.

Datum of the gage: 412.840 ft NAVD88 based on a Level 2 Static GNSS Survey processed through OPUS, Ref Frame NAD83 (2011)(EPOCH:2010.0000) ITRF2014 (EPOCH:2023.7802) and Geoid 18. The survey was completed on October 12th, 2023 while occupying a TRM referenced to local gage datum via differential levels.

Prior to 10/12/2023 the datum of the gage was 412.60 ft NGVD29 based on USGS BM 34 JJL 1961 used as an origin for a survey level line to carry NGVD29 to the new gage install.

REMARKS - Records fair. Since water year, 1980, at least 10% of contributing drainage area has been regulated. No known diversions. No flow at times. Some records listed in the "Period of Record" for surface water and water quality may not be available electronically.

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).