USGS Water-Year Summary 2024
04024000 ST. LOUIS RIVER AT SCANLON, MN
LOCATION - Lat 46°42'12", long 92°25'07" referenced to North American Datum of 1927, in SE 1/4 NW 1/4 sec.30, T.49 N., R.16 W., Carlton County, MN, Hydrologic Unit 04010201, on right bank 80 ft downstream from bridge on U.S. Highway 61 at Scanlon, 0.6 mi downstream from Minnesota Power Co. power plant, 3 mi upstream from Thomson Reservoir, and 3.2 mi upstream from Midway River. The YSI QW site monitor is located on the headwater side of the Scanlon Dam located approx. 1/2 mile US of stream gage.
DRAINAGE AREA - 3,430 mi².
REVISIONS HISTORY - WSP 1337: 1911-12.
SURFACE-WATER RECORDS
PERIOD OF RECORD - January 1908 to current year. Monthly discharge only for some periods published in WSP 1307. Published as "near Thomson" 1908-50.
GAGE - Water-stage recorder. Oct. 5, 1909 to Sept. 5, 1914, non-recording gage 3 mi downstream and 50 ft below power plant at datum about 420 ft lower. Sept. 6, 1914 to Aug. 4, 1953, power plant record at Thomson hydroelectric plant. Datum of gage is 1101.08 ft. above mean sea level NAVD88.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 45,300 ft³/s, gage-height 16.62 ft, June 21, 2012; maximum daily-mean discharge, 45,000 ft³/s, June 21, 2012; minimum discharge 88 ft³/s, Aug. 24, 1977 (discharge affected by regulation; lowest daily-mean discharge).
WATER-QUALITY RECORDS
PERIOD OF RECORD - SPECIFIC CONDUCTANCE: Oct. 1980 to Sept. 1983, April, 2011 to current year.
pH: April, 2011 to current year.
WATER TEMPERATURE: Oct. 1980 to Sept. 1983, April, 2011 to current year.
DISSOLVED OXYGEN: April, 2011 to current year.
TURBIDITY: April, 2011 to current year.
INSTRUMENTATION - Water-quality monitor April 21, 2011 to current year, which provides continous readings. Sensor is located on the Scanlon Dam structure approximately 1/2 mile above the gage.
EXTREMES FOR PERIOD OF RECORD - SPECIFIC CONDUCTANCE: Maximum, 391 uS/cm, Oct. 8, 2021; minimum, 61 uS/cm, June 21, 2012.
pH: Maximum, 9.0, August 30, 2015; minimum, 6.7, June 21, 2012 and June 4, 2014.
WATER TEMPERATURE: Maximum, 29.2 C, July 3, 2020; minimum, 0.0 C, many days, most years.
DISSOLVED OXYGEN: Maximum, 15.2 mg/l, April 4, 2020; minimum, 5.0 mg/l, May 29, 2023.
TURBIDITY: Maximum, 160 FNU, June 20, 2012; minimum, 0.3 FNU, August 28, 2023.