USGS Water-Year Summary for Site 08068000

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	Available Parameters
	00010 Temperature, water(Max.,Min.,Mean)
	00060 Discharge(Mean)
	00065 Gage height(Mean)
	00095 Specific cond at 25C(Max.,Min.,Mean)
	00300 Dissolved oxygen(Max.,Min.,Mean)
	00400 pH(Max.,Min.)
	63680 Turbidity, Form Neph(Mean,Max.,Min.)

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

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USGS Water-Year Summary 2024

08068000 West Fork San Jacinto River near Conroe, TX

LOCATION - Lat 30°14'40", long 95°27'25" referenced to North American Datum of 1927, Montgomery County, TX, Hydrologic Unit 12040101, near center of bridge on downstream side of Interstate Highway 45 at mile 79 on northbound feeder road, 300 ft upstream from Missouri Pacific Railroad Co. bridge, 3.5 mi downstream from Lake Creek, 4.2 mi south of Conroe.

DRAINAGE AREA - 828 mi².

REVISIONS HISTORY - WSP 1058: 1926. WSP 1732: Drainage area. WDR TX-79-2: Drainage area. Daily values revised: February 20- June 26.

SURFACE-WATER RECORDS

PERIOD OF RECORD - May 1924 to Sept. 1927, July 1939 to current year.

GAGE - Water-stage recorder. Datum of gage is NAVD 1988. Prior to Oct. 1, 2012, datum of gage was 95.03 ft above NGVD of 1929 (93.80 ft above current datum). May 7, 1924, to Sept. 30, 1927, nonrecording gage at railroad bridge 300 ft downstream at datum 30.10 ft higher. July 13, 1939, to Sept. 30, 1963, water-stage recorder at datum 5.0 ft higher. Satellite telemeter at station.

REMARKS - Since water year 1973, at least 10% of contributing drainage area has been regulated. There are no large diversions above 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 - Flood in Dec. 1913 reached a stage of 30.2 ft, present site and datum then in use, from information by Missouri Pacific Railroad Co., discharge 101,000 ft³/s, from rating curve as explained below.

EXTREMES FOR PERIOD PRIOR TO REGULATION - WATER YEARS, 1925-1927, 1940-1972: Maximum discharge, 110,000 ft³/s Nov. 25, 1940 (gage height, 30.85 ft), datum then in use, from rating curve extended above 43,000 ft³/s on basis of velocity-area studies; no flow June 14, 1956, and Sept. 19 to Oct. 1, 1965, result of temporary dams. Maximum stage since at least Dec. 1913, that of Nov. 25, 1940.

AVERAGE DISCHARGE FOR PERIOD PRIOR TO REGULATION - 36 years (water years 1925-27, 1940-72), prior to regulation by Lake Conroe, (station 08067600) 477 ft³/s (345,600 acre-ft/yr).

WATER-QUALITY RECORDS

PERIOD OF RECORD - CHEMICAL DATA: Mar. 1959 to Sept. 1994, Aug. 2011. BIOCHEMICAL DATA: Mar. 1959 to Sept. 1994, Aug. 2011. PESTICIDE DATA: May 1975 to June 1982. SEDIMENT DATA: Feb. 1966 to Sept. 1967, Oct. 1974 to Sept. 1994, Sept. 2008 to Aug. 2011.

PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: Oct. 1961 to Sept. 1990, Feb. 2014 to current. pH: Feb. 2014 to current. WATER TEMPERATURE: Oct. 1961 to Sept. 1990, Feb. 2014 to current. DISSOLVED OXYGEN: Aug. 1979 to May 1981, Feb. 2014 to current. TURBIDITY: Feb. 2014 to current.

REMARKS - Interruptions or periods of missing record may be due to instrument failure, no flow conditions or data corrections exceeding allowable criteria, which were deleted. Other than no flow conditions, minimum and maximum extremes may have occurred during period of missing record. Some records listed in the "Period of Record" for surface water and water quality may not be available electronically.

EXTREMES FOR PERIOD OF RECORD - --WATER TEMPERATURE: Maximum, 37.0 °C, June 26, 1984; minimum, 0.0 °C, Dec. 22, 1963. SPECIFIC CONDUCTANCE: Maximum, 1,330 ms/cm, Sept. 12, 2014; minimum, 40 ms/cm. Nov. 24, 1985. pH: Maximum, 9.1 standard units, Mar 5, 2015; minimum, 6.5 standard units, Nov. 26, 2014. DISSOLVED OXYGEN: Maximum, 17.5 mg/L, Mar. 5, 2015; minimum, 2.3 mg/L July 3, 2014. TURBIDITY: Maximum, 1250 FNU, June 26, 2014 and July 3, 2014; minimum, 2.1 FNU, Feb. 14, 2016 and Feb. 16, 2016.