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Water-Year Summary for Site 12448000

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  • Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
  • For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
  • For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
  • For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
  • Not all sites have reports available for every water year.
Available Parameters
00010 Temperature, water(Max.,Min.,Mean)  
00021 Temperature, air(Max.,Min.,Mean)  
00060 Discharge(Mean)  
00065 Gage height(Mean)  

Water year 2023: 2022-10-01 to 2023-09-30

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USGS Water-Year Summary 2023
LOCATION - Lat 48°28'38", long 120°11'07" referenced to North American Datum of 1927, in SW 1/4 NW 1/4 sec.02, T.34 N., R.21 E., Okanogan County, WA, Hydrologic Unit 17020008, on right bank, 80 ft downstream from State Road 20 bridge crossing, at northwest end of Winthrop, WA, and at mile 0.2.
DRAINAGE AREA - 525 mi².
PERIOD OF RECORD - 1912 to 1913, seasonal records only. October 1991 to current year. Prior to October 1991 published as "Chewack River at Winthrop, WA".
GAGE - Water-stage recorder. Datum of gage is 1,736.26 ft above NGVD of 1929 (Okanogan County Public Works benchmark). Prior to November 1991, nonrecording gage 10 ft upstream from bridge, and at datum 8.74 ft higher.
REMARKS - No known regulation. Several diversions for irrigation upstream from station. U.S. Geological Survey satellite telemeter at station. Water temperature records April to September 2002.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum discharge, 18,100 ft³/s May 29, 1948, determined by slope-area measurement of peak flow.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 8,910 ft³/s May 9, 2018, gage height, 10.64 ft; minimum discharge, 20 ft³/s Sept. 18 and 19, 2001, gage height, 2.24 ft.