USGS Water-Year Summary 2024

12398600 PEND OREILLE RIVER AT INTERNATIONAL BOUNDARY

LOCATION - Lat 48°59'56", long 117°21'09" referenced to North American Datum of 1927, in SW 1/4 NE 1/4 sec.03, T.40 N., R.43 E., Pend Oreille County, WA, Hydrologic Unit 17010216, on left bank 0.1 mi upstream from international boundary, 0.9 mi downstream from Boundary Dam, 6.0 mi downstream from Slate Creek, 9.7 mi north of Metaline Falls, and at mile 16.1.

DRAINAGE AREA - 25,200 mi².

REVISIONS HISTORY - WSP 442: 1913. WSP 1716: 1919.

SURFACE-WATER RECORDS

PERIOD OF RECORD - November 1908 to September 1910 (gage heights only), December 1912 to October 1995, October 1996 to current year. Prior to October 1928, published as "Clark Fork at Metaline Falls," October 1928 to September 1937 as "Clark Fork below Z Canyon, near Metaline Falls," and October 1938 to September 1964 as "below Z Canyon, near Metaline Falls." Concurrent records published for present site December 1962 to September 1964.

GAGE - Daily discharge determined from flow through turbines plus spillway flow when present. Datum of gage is 1,700.00 ft above NGVD of 1929 (City of Seattle Boundary Dam datum). Prior to Dec. 20, 1928, non-recording gage at Metaline Falls at datum approximately 1,983.4 ft above NGVD of 1929. Dec. 20, 1928, to Sept. 30, 1964, water-stage recorder at site 1.3 mi upstream at datum 1,721.18 ft NGVD of 1929 (levels by Corps of Engineers).

COOPERATION - Discharge records at Boundary Dam provided by Seattle City Light's Power Resources Branch. The U.S. Geological Survey makes discharge measurements at this site during the year.

REMARKS - Flow regulated by Boundary Reservoir 0.9 mi upstream beginning April 1967, Box Canyon Reservoir beginning June 1955, Pend Oreille Lake beginning June 1952, Flathead Lake beginning April 1938, Hungry Horse Reservoir beginning September 1951, and by several smaller reservoirs and power plants. In 1980 there were diversions for irrigation of 429,700 acres upstream from the station and there probably has not been any appreciable change since that time.

EXTREMES OUTSIDE PERIOD OF RECORD - Flood of June 1894 reached a stage of 69.0 ft, from floodmarks, at site and datum 1.3 mi upstream.

EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 171,300 ft³/s, June 13, 1948, gage height, 60.25 ft, site and datum then in use; minimum discharge, no flow occurs numerous times a year, result of regulation.

WATER-QUALITY RECORDS

PERIOD OF RECORD - Chemical analyses October 1973 to September 1986. Water years 1974 to 1981 (National Stream-quality Accounting Network Station). Water-quality monitor April 1999 to current year. Barometric Pressure record April 1999 to September 2013, available in files of the U.S. Geological Survey Spokane Field Office. October 2013 to current year.

PERIOD OF DAILY RECORD - SPECIFIC CONDUCTANCE: January 1974 to September 1981. WATER TEMPERATURE: April 1974 to September 1981, April 1999 to current year. TOTAL DISSOLVED GAS: May 1999 to current year. BAROMETERIC PRESSURE: October 2013 to current year.

INSTRUMENTATION - Water-quality monitor April 1974 to September 1981; April 1999 to current year, with a 15-minute logging interval.

REMARKS -  

EXTREMES FOR PERIOD OF DAILY RECORD -

SPECIFIC CONDUCTANCE: Maximum, 242 microsiemens, July 17, 1974; minimum, 62 microsiemens, Apr. 25, 1975.

WATER TEMPERATURE: Maximum, 25.3°C July 10, 2015; minimum, -0.2°C, at times during winter periods.

TOTAL DISSOLVED GAS: Maximum, 154 percent saturation, June 2, 9, 2011, but may have been higher during periods of missing record; minimum, 82 percent saturation, Dec. 19, 2016, but may have been lower during periods of missing record.

BAROMETRIC PRESSURE: Maximum 737 mm/Hg, Dec. 30, 2014, but may have been higher during periods of missing record; minimum, 692 mm/Hg, December 23, 2021, but may have been lower during periods of missing record.