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Water-Year Summary for Site 12318500

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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(Mean,Max.,Min.)  
00065 Gage height(Mean)  

Water year 2021: 2021-10-01 to 2022-09-30

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USGS Water-Year Summary 2021
LOCATION - Lat 48°54'18", long 116°24'07" referenced to North American Datum of 1983, in NW 1/4 NE 1/4 NE 1/4 sec.13, T.64 N., R.1 W., Boundary County, ID, Hydrologic Unit 17010104,
PERIOD OF RECORD - October 1927 to September 1992 (discontinued) (Elevation record prior to only to May 1929). Publish as "at Copeland" 1927-29. April 1925 to September 1927 (gage height only) as reports of Water Survey of Canada. April 2018 to present.
GAGE -  Water-stage recorder and temperature sensor. Datum of gage is 1,700.00 ft above Topographic Division datum of 1928. Gage readings have been reduced to that datum. NGVD of 1929 is about 0.03 ft higher. Prior to September 30, 1975, water-stage recorder located 1 mi downstream at same datum. Oct 1927 to Nov. 20, 1929, nonrecording or recording gage at site downstream 0.2 mi; datum 40.77 ft higher Prior to April 18, 1929.
REMARKS - Station equipment includes satellite telemetry. Elevations affected by backwater from Kootenay Lake. No drainage district dike failed during year. Flow regulated by Libby Dam since Mar. 21, 1972. Add 1,700 ft to gage heights to obtain elevations.
EXTREMES FOR PERIOD OF RECORD - UNREGULATED PERIOD (1929-71).--Maximum daily discharge, 124,000 ft/s May 30, 1948, maximum elevation, 1,772.55 ft, June 6, 1961; minimum daily discharge, 1,350 ft³/s Feb. 8, 1936; minimum elevation, 1,738.52, Apr. 2, 3, 1944. REGULATED PERIOD (1972-92).--Maximum daily discharge since regulation by Libby Dam, 56,700 ft³/s May 18, 1972; minimum daily discharge, 1,900 ft³/s Jan. 31, 1972.
PERIOD OF RECORD - Water Temperature: July 2020 to current year.