Warning: Javascript must be enabled to use all the features on this page!

Page Loading - Please Wait...

Click to hideNews Bulletins

Water-Year Summary for Site 12372000

Click to hide Water-Year Summary instructions and information
  • 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
00060 Discharge(Mean)  

Water year 2020: 2019-10-01 to 2020-09-30

Print this page
USGS Water-Year Summary 2020
LOCATION - Lat 47°40'49.03", long 114°14'48.22" referenced to North American Datum of 1983, in SW 1/4 NE 1/4 SE 1/4 sec.11, T.22 N., R.21 W., Lake County, MT, Hydrologic Unit 17010212, on left bank 0.5 mi downstream from Kerr Dam, 4.0 mi west of Polson, 5.0 mi downstream from Flathead Lake, and at river mile 71.5.
DRAINAGE AREA - 7,079 mi².
REVISIONS HISTORY - Water Supply Paper (WSP) 652: 1926. WSP 752: 1932. WSP 1182: 1948. WSP 1216: Drainage area. WSP 1246: 1928, maximum discharge. WSP 1636: 1958, adjusted runoff.
PERIOD OF RECORD - July 1907 to current year.
GAGE - Water-stage recorder. Elevation of gage is 2,692.70 ft, referenced to the National Geodetic Vertical Datum of 1929 (levels by The Montana Power Co.). Prior to Oct. 1, 1941, nonrecording gages or water-stage recorder at several sites near highway bridge at old site of Michell's ferry 6 mi downstream from present site, all at elevation 2,629.20 ft (from river-profile survey). U.S. Geological Survey satellite telemeter is located at the station.

2020 Water Year: records are good.
2019 Water Year: records are good.
2018 Water Year: records are good.
2017 Water Year: records are good.
2016 Water Year: records are good.
2015 Water Year: records are good, except estimated records are fair.
2014 Water Year: records are good, except estimated records are fair. 

Flow is regulated by Flathead Lake (Kerr Dam) since April 1938 (station number 12371500) and Hungry 
Horse Reservoir (station number 12362000) since September 1951. Diversions occur upstream from station 
for irrigation of about 10,000 acres. Flathead project pumps can divert up to 12,000 acre-ft per month 
when required for irrigation of lands downstream from station.


EXTREMES OUTSIDE PERIOD OF RECORD - Flood in June 1894 reached a stage of about 21 ft, present elevation; discharge, about 110,000 ft³/s, from lake elevation-discharge study.
AVERAGE DISCHARGE FOR PERIOD OF RECORD - 107 years, 11,570 ft³/s, 22.14 in/yr, 8,382,000 acre-ft/yr, adjusted for change in contents in Hungry Horse Reservoir and Flathead Lake.