USGS Water-Year Summary for Site 08159200

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

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

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USGS Water-Year Summary 2023

08159200 Colorado River at Bastrop, TX

LOCATION - Lat 30°06'16", long 97°19'09" referenced to North American Datum of 1927, Bastrop County, TX, Hydrologic Unit 12090301, on the left bank on the downstream side of State Highway 71 bridge on Water Street, at Bastrop, 0.3 mi upstream from Gills Creek, 1.2 mi downstream from Piney Creek, and at mile 236.6.

DRAINAGE AREA - 39,979 mi² of which 11,403 mi² probably is noncontributing.

REVISIONS HISTORY - WDR TX-81-3: Drainage area.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Mar. 1960 to current year. Oct. 1973 to Sept. 1975, daily discharges estimated by hydrographic comparison with Colorado River at Austin (station 08158000) and Colorado River near Smithville (station 08159500). PERIOD OF RECORD, Water-Quality.-- CHEMICAL DATA: Jan. 1968 to Aug. 1994. BIOCHEMICAL DATA: Feb. 1968 to Sept. 1994. RADIOCHEMICAL DATA: Jan. 1981 to July 1981. PERIOD OF DAILY RECORD, Water-Quality.-- SPECIFIC CONDUCTANCE: Oct. 1984 to Sept. 1994. WATER TEMPERATURE: Oct. 1984 to Sept. 1994. pH: Oct. 1984 to Sept. 1994. DISSOLVED OXYGEN: Oct. 1984 to Sept. 1994.

GAGE -

Water-stage recorder. Radio and satellite telemetry at station.

Datum of gage: 307.408 ft NAVD88 based on a Level 2 Static GNSS survey processed through OPUS, Ref Frame NAD83 (2011)(EPOCH:2010.0000) ITRF2014 (EPOCH:20236295) and Geoid18. The survey was completed on August 18th, 2023, while occupying a TRM referenced to local gage datum via differential levels.

Prior to 8/18/2023: the datum of the gage was 307.38 ft NGVD29. Prior to Sept. 30, 1973, and Oct. 1, 1975 to Oct. 28, 1986, 400 ft upstream from present site at same datum.

COOPERATION - Lower Colorado River Authority provides operational and maintenance assistance of the gage and measures streamflow to verify the stage-discharge relation at low stages. U.S. Geological Survey maintains stage-discharge relation for all stages, computes, and publishes streamflow record.

REMARKS - Records good. Since installation of gage in 1960, at least 10% of contributing drainage area has been regulated. There are many diversions above station for irrigation and municipal supply. The city of Austin diverts water into Decker Lake (by pumpage) upstream from this station. The Lower Colorado River Authority also diverts water from the Colorado into Lake Bastrop (by pumpage) upstream from this station. 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 at least 1845, 60.3 ft July 7 or 8, 1869. Flood of June 16, 1935, reached a stage of 57.0 ft, and flood of Dec. 4, 1913, reached a stage of 53.3 ft, from information by local resident.