USGS Water-Year Summary for Site 08147000

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	Available Parameters
	00060 Discharge(Mean,Max.,Min.)
	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

08147000 Colorado River near San Saba, TX

LOCATION - Lat 31°13'04", long 98°33'51" referenced to North American Datum of 1927, Lampasas County, TX, Hydrologic Unit 12090201, on left bank at downstream side of bridge on U.S. Highway 190, 5.2 mi downstream from San Saba River, 9.2 mi east of San Saba, and at mile 474.3.

DRAINAGE AREA - 31,217 mi² of which 11,398 mi² probably is noncontributing.

REVISIONS HISTORY - WSP 458: 1916. WSP 858: 1900(M), 1936(M). WSP 1512: 1916-18(M), 1936. WSP 1732: 1925-26(M). WDR TX-81-3: Drainage area.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Oct. 1915 to Oct. 1922, published as "near Chadwick", Oct. 1923 to Aug. 1930, published as "near Tow", Sept. 1930 to current year. Monthly discharge only for some periods, published in WSP 1312. PERIOD OF RECORD, Water-Quality.-- CHEMICAL DATA: Oct. 1959 to Aug. 1993. BIOCHEMICAL DATA: Oct. 1959 to Aug. 1993. BIOLOGICAL DATA: Oct. 1977 to Aug. 1993. PESTICIDE DATA: Jan. 1968 to Apr. 1982. RADIOCHEMICAL DATA: Dec. 1980 to July 1981. SEDIMENT DATA: Oct. 1960 to Aug. 1993. PERIOD OF DAILY RECORD, Water-Quality.-- SPECIFIC CONDUCTANCE: Sept. 1947 to Sept. 1992. WATER TEMPERATURE: Sept. 1947 to Sept. 1992.

GAGE - Water-stage recorder. Datum of gage is 1,096.29ft above NAVD88 as determined by GNSS survey. Prior to December 19, 2023, the datum of gage was 1,096.22ft above NGVD of 1929. See WSP 1922 for brief history of changes prior to May 23, 1940. Radio telemeter at station. Satellite telemeter at station.

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

REMARKS - Since water year 1931, at least 10% of contributing drainage area has been regulated. Flow is also affected at times by discharge from the flood-detention pools of 187 floodwater-retarding structures. These flood-detention structures control runoff from a 944 mi² area above this station. There are many diversions above station for irrigation, municipal use, and for oil field operations. No flow at times. Some records listed in the period of record may not be available electronically.

EXTREMES OUTSIDE PERIOD OF RECORD - Maximum stage during period 1878 to Sept. 1930, 58.4 ft, Sept. 25, 1900, discharge 184,000 ft³/s, present site, from floodmarks at former site.

EXTREMES FOR PERIOD PRIOR TO REGULATION - WATER YEARS 1917-1919, 1921-1922, 1924-1930: Maximum discharge, 130,000 ft³/s, Apr. 26, 1922, gage height about 54.0 ft, present site, from information by local residents; minimum observed discharge, 1.5 ft³/s, Aug. 22, 23, 1918.

AVERAGE DISCHARGE FOR PERIOD PRIOR TO REGULATION - 12 years (water years 1917-19, 1921-22, 1924-30) prior to completion of Lake Nasworthy, 1,440 ft³/s (1,040,000 acre-ft/yr).