USGS Water-Year Summary for Site 08136000

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

08136000 Concho River at San Angelo, TX

LOCATION - Lat 31°27'16", long 100°24'37" referenced to North American Datum of 1927, Tom Green County, TX, Hydrologic Unit 12090105, on left bank 0.4 mi downstream from confluence of North and South Concho Rivers, 1.8 mi southeast of Tom Green County Courthouse, in San Angelo at Rio Concho Sports Complex on Rio Concho Dr. below Bell St. bridge, and 61.9 mi upstream from mouth.

DRAINAGE AREA - 5,542 mi² of which 1,131 mi² probably is noncontributing.

REVISIONS HISTORY - WSP 568: 1915-16, 1919-22. WSP 1148: 1916-22(M), 1924(M), 1925-26, 1929(M), 1930-32, 1935-37. WSP 1512: 1917-18. WSP 1712: 1936. WDR TX-81-3: Drainage area.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Oct. 1915 to current year. Prior to Oct. 1969, published as "near San Angelo". PERIOD OF RECORD, Water-Quality.-- BIOCHEMICAL DATA: Oct. 1968.

GAGE -

Water-stage recorder and concrete control. Datum of gage is 1,777.10 ft. above NAVD88.

Prior to Mar. 21, 2022, datum of the gage was listed as 1776.79 ft. above NGVD29. Prior to Aug. 11, 1917, nonrecording gage at same site and datum. Aug. 11, 1917, to May 15, 1963, water-stage recorder on right bank at same datum. Satellite telemeter at station.

REMARKS - Since water year 1931, at least 10% of contributing drainage area has been regulated. There are many diversions upstream from station for irrigation, industrial, and municipal supply. No flow at times. Some records listed in the period of record may not be available electronically.

EXTREMES OUTSIDE PERIOD OF RECORD - Maximum stage since 1853, 47.5 ft, Aug. 6, 1906, discharge, about 246,000 ft³/s, from information by local resident. Other large floods are known to have occurred in June 1853, Aug. 1882, and Apr. 1900.

EXTREMES FOR PERIOD OF RECORD - Maximum stage during period of regulation, 46.60 ft, Sept. 17, 1936, discharge, 230,000 ft³/s from a slope-area measurement.

EXTREMES FOR PERIOD PRIOR TO REGULATION - WATER YEARS, 1916-1930: Maximum discharge, 92,000 ft³/s, Apr. 26, 1922, gage height, 36.8 ft, from floodmarks, on basis of slope-area measurements of 167,000 and 230,000 ft³/s in 1936; no flow at times in 1921.

AVERAGE DISCHARGE FOR PERIOD PRIOR TO REGULATION - 15 years (water years 1916-30) prior to completion of Lake Nasworthy, 142 ft³/s (102,600 acre-ft/yr).