USGS Water-Year Summary 2024

08158000 Colorado River at Austin, TX

LOCATION - Lat 30°14'46.1", long 97°40'48.2" referenced to North American Datum of 1983, Travis County, TX, Hydrologic Unit 12090205, on right bank, 3300 ft. downstream from downstream bridge on U.S. Highway 183 in Austin, 2 mi downstream from Longhorn Dam, and at mile 291.

DRAINAGE AREA - 39,009 mi² of which 11,403 mi² probably is noncontributing.

REVISIONS HISTORY -

WSP 508: 1915(m). WSP 528: 1900(M), 1918(m). WSP 548: 1901-16. WSP 1342: Drainage area. WSP 1562: 1908, 1929(M), 1936.

Revisions: (12/3/2020) Discharge for the period May 25th, 2015 - August 27th, 2015 was revised because of computational changes made to Qms 1817, 1818, and 1819 that resulted in necessary revisions to shifted ratings following SW Technical Memo 2017.07.  This in turn affected IV discharge values below ~1100 cfs, and affected Daily Min, Max, and Mean discharge values as well for the revised period. The POY discharge was unaffected by the revisions. 

Revisions: (12/3/2020) Discharges 1719, 1720, 1747, and 1748 in 2013 were revised because of computational changes made to each and noted in FDE in Aquarius.  Following SW Technical Memo 2017.07, no revisions to the shifted rating were needed.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Mar. 1898 to current year. Records of daily discharge for Dec. 13-26, 1914, and Feb. 9-17, 1915, published in WSP 408, have been found unreliable and should not be used. PERIOD OF RECORD, Water-Quality.-- CHEMICAL DATA: Oct. 1947 to Aug. 1993. BIOCHEMICAL DATA: Oct. 1967 to Aug. 1993. BIOLOGICAL DATA: Jan. 1974 to Aug. 1993. SEDIMENT DATA: Jan. 1974 to Aug. 1993. RADIOCHEMICAL DATA: Jan. to July 1981. TAXONOMIC DATA: July 1974 to Sept. 1981. PERIOD OF DAILY RECORD, Water-Quality.-- SPECIFIC CONDUCTANCE: Oct. 1947 to Sept. 1991. WATER TEMPERATURE: Oct. 1947 to Sept. 1991.

GAGE -

Water-stage recorder. Satellite telemetry at station.

Datum of the gage:  391.96 ft NAVD 88 Determined by a survey level line from NGS BM 0567.  Activated after gage relocation in August 2012. 

Prior to the 2012 gage relocation the datum of the gage was 402.27 ft above NGVD of 1929. Prior to June 19, 1939, all records collected at or near Congress Avenue bridge 3.9 mi upstream at datum 19.6 ft higher; prior to June 18, 1915, nonrecording gages, recording gages thereafter; June 20, 1939, to Oct. 16, 1963, at site 1,000 ft downstream from present site at datum 5.0 ft higher. Satellite telemeter at station. On August 2, 2012 the station was permanently relocated 0.85 mile downstream of the previous location (0.63 miles downstream from US 183 bridge).

COOPERATION - Lower Colorado River Authority provides operation and maintenance of the gage and verification of stage-discharge relation at low stages. U.S. Geological Survey maintains stage-discharge relation at medium to high stages, computes and publishes streamflow record.

REMARKS - Since installation of gage in 1898, at least 10% of contributing drainage area has been regulated. The city of Austin diverts water for municipal use upstream from station and returns wastewater effluent downstream. There are many other diversions above Lake Buchanan for irrigation, municipal supplies, and oil field operations. 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 1833, 51 ft. July 7, 1869, discharge 550,000 ft³/s, present site and datum (adjusted to present site on basis of record for flood of June 15, 1935), determined from information concerning stage at former site furnished by Dean T.U. Taylor.