USGS Water-Year Summary for Site 08153500

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

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Water year 2024: 2024-10-01 to 2025-09-30

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USGS Water-Year Summary 2024

08153500 Pedernales River near Johnson City, TX

LOCATION - Lat 30°17'30", long 98°23'57" referenced to North American Datum of 1927, Blanco County, TX, Hydrologic Unit 12090206, near left downstream end of bridge on U.S. Highway 281, 0.2 mi downstream from Towhead Creek, 1.1 mi northeast of Johnson City, 3.4 mi downstream from Buffalo Creek, and 48.0 mi upstream from mouth.

DRAINAGE AREA - 901 mi².

REVISIONS HISTORY - WSP 1632: 1953(M), 1957, 1958(M). WDR TX-81-3: Drainage area. WRD TX-03-4.

SURFACE-WATER RECORDS

PERIOD OF RECORD - May 1939 to current year. PERIOD OF RECORD, Water-Quality.-- CHEMICAL DATA: Apr. 1948 to Sept. 1950, Feb. 1969 to Sept. 1985. BIOCHEMICAL DATA: Feb. 1969 to Sept. 1973. BIOLOGICAL DATA: Feb. 1969 to Apr. 1969. RADIOCHEMICAL DATA: Nov. 1980 to June 1981.

GAGE -

Water-stage recorder and concrete control. Satellite telemetry at station.

Datum of the gage: 1096.687 ft NAVD88 based on a Level 2 Static GNSS survey processed through OPUS, Ref Frame: NAD83 (2011)(EPOCH:2010.0000) ITRF2014 (EPOCH:2024.2016) and Geoid 18. The survey was completed March 14th, 2024 while occupying a TRM that was referenced to local gage datum via differential levels.

Prior to 3/14/2024, the Datum of the gage was 1,096.70 ft NGVD29. May 4 to Sept. 13, 1939, nonrecording gage, and Sept. 14, 1939, to Sept. 10, 1952, water-stage recorder at upstream side of bridge at same datum. Sept. 11, 1952, to June 29, 1953, nonrecording gage, and June 30, 1953, to Oct. 7, 1954, water-stage recorder at site 360 ft downstream at same datum. Radio telemeter at station.

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 - Records good. except for discharges below 10 ft³/s, which are poor. There are diversions above station for irrigation. During the year, the city of Fredericksburg discharged varying amounts of wastewater effluent into the river upstream from station. The city of Johnson City diverts varying amounts of water from the pool at gage and discharges wastewater effluent into river below the gage. 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 - Flood of July 1869, reached a stage of 33 ft from information by local residents.