USGS Water-Year Summary 2021
12442500 SIMILKAMEEN RIVER NEAR NIGHTHAWK, WA
LOCATION - Lat 48°59'05", long 119°37'02" referenced to North American Datum of 1927, in NW 1/4 sec.07, T.40 N., R.26 E., Okanogan County, WA, Hydrologic Unit 17020007, on left bank 1,000 ft upstream from Oroville-Tonasket Irrigation District canal intake, 1.6 mi northeast of Nighthawk, 3.8 mi downstream from Palmer Creek, and at mile 15.8.
DRAINAGE AREA - 3,550 mi².
- WSP 1183: Drainage area.
PERIOD OF RECORD - May 1911 to current year (prior to September 1928, mean monthly discharge included Oroville-Tonasket Irrigation District canal). Published as "near Oroville" 1911-28.
GAGE - Water-stage recorder. Datum of gage is 1,137.70 ft above NGVD of 1929. Prior to Sept. 11, 1928, staff gages at sites 7 mi downstream (below Oroville-Tonasket Irrigation District canal) at various datums.
COOPERATION - This station is maintained by the United States under agreement with Canada.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 45,800 ft³/s, June 1, 1972; maximum gage height, 18.78 ft, May 31, 1972; minimum discharge, 65 ft³/s, Jan. 3, 1974; minimum gage height, 1.55 ft, Jan. 31, 1988, result of freezeup.
PERIOD OF RECORD - April 1986 to September 1987, March 2014 to current year.
INSTRUMENTATION - Water temperature recorder with a 15-minute logging interval.
EXTREMES FOR PERIOD OF DAILY RECORD - Maximum, 23.6°C, July 27, 2017; Minimum, -0.3°C many days in winter.