USGS Water-Year Summary for Site 05437500

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	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

05437500 ROCK RIVER AT ROCKTON, IL

LOCATION - Lat 42°27'01", long 89°04'21" referenced to North American Datum of 1983, in SW 1/4 SE 1/4 NW 1/4 sec.24, T.46 N., R.12 E., Winnebago County, IL, Hydrologic Unit 07090005, on upstream side of bridge on State Highway 75 in Rockton, 1.0 mi downstream from Pecatonica River, and at mile 156.1.

DRAINAGE AREA - 6,363 mi².

REVISIONS HISTORY -

Gage height and discharge for the period Nov. 6, 2014, to Apr. 22, 2020, were revised on Jun. 1, 2020, based on changes to the gage datum."

WSP 325: 1903-9. WSP 895: 1904(M). WSP 1508: 1915, 1916-17(M). WDR IL-75-1: Drainage area. WDR IL-97-1: 1996 (Dec. 10-23).

SURFACE-WATER RECORDS

PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE
  DISCHARGE: June 1903 to July 1906, October 1906 to November 1907,
    January 1908 to March 1909, July 1914 to September 1919, October 1939 to current.
    Published as "below mouth of Pecatonica River at Rockton" 1903-9; as "at Rockford" 1914-19.
    Monthly discharge only for some periods for 1903-1950, published in WSP 1308.
  STAGE: Water years 1994 to current.
SURFACE-WATER QUALITY
  CHEMICAL: Water years 1978-91 and 2009-2011.

GAGE -

Water-stage recorder, U.S. Army Corps of Engineers satellite telemeter, and crest-stage gage.

Datum of gage is 707.75 ft NAVD 1988. However, datum incorrectly published as 708.79 ft NAVD 1988 from Feb. 3, 2020 to Apr. 22, 2020.

Prior to Oct. 1, 1906, nonrecording gage at site at datum about 1.0 ft higher.

Oct. 1, 1906 to Mar. 31, 1909, nonrecording gage at site at datum about 2.0 ft higher.

July 30, 1914 to Apr. 30, 1919, nonrecording gage at site at Rockford about 21 mi downstream, at different datum.

Oct. 1, 1939, to Aug. 10, 1973, at site at datum 707.94 ft above NGVD of 1929 (levels by U.S. Army Corps of Engineers).

Aug. 10, 1973, to Nov. 6, 2014, at site 800 ft. downstream, at datum 707.94 ft. above NGVD of 1929.

REMARKS - Low flow regulated by powerplant upstream from station. Accuracy of records is discussed in the annual Station Analysis archived at the USGS IL Water Science Center.

EXTREMES OUTSIDE PERIOD OF RECORD - SURFACE-WATER DISCHARGE AND STAGE: Flood in February 1937 reached a stage of 14.6 ft (gage datum 707.94 ft above NGVD of 1929) (backwater from ice), from floodmark.

EXTREMES FOR PERIOD OF RECORD - SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 32,500 ft³/s, Mar. 30, 1916, gage height, 13.06 ft, site and datum then in use; maximum gage height, 15.54 ft, Mar. 25, 1975, discharge 30,000 ft³/s, site and datum then in use; minimum daily discharge, 501 ft³/s, Sept. 14, 1958.