USGS Water-Year Summary 2024
05543500 ILLINOIS RIVER AT MARSEILLES, IL
LOCATION - Lat 41°19'37.2", long 88°43'01.5" referenced to North American Datum of 1983, in SE 1/4 SW 1/4 sec.13, T.33 N., R.4 E., LaSalle County, IL, Hydrologic Unit 07120005, on right bank 0.5 mi downstream from Marseilles dam in Marseilles, 6.9 mi upstream from Fox River, and at mile 246.5.
DRAINAGE AREA - 8,259 mi². does not include diversion from Lake Michigan through the Chicago Sanitary and Ship Canal, which has occurred since Jan. 17, 1900.
REVISIONS HISTORY - WDR IL-75-1: Drainage area.
SURFACE-WATER RECORDS
PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE
DISCHARGE: October 1919 to current. Prior to October 1939, published as "at Morris."
STAGE: Water years 1994 to current.
PARTIAL RECORD: Annual maximum, water years 1894 to 1898 and 1900 to 1919.
SURFACE-WATER QUALITY
CHEMICAL: Water years 1975-97.
SEDIMENT: February 2003 to September 2009.
SPECIFIC CONDUCTANCE: Water years 1975-81.
WATER TEMPERATURE: Water years 1975-81.
MISCELLANEOUS: Water Year 1998; Contaminants in streambed sediments, October 1996;
contaminants in fish tissue, October 1996; sediment concentration and
particle size, water years 1993-97, 2003-2005.
BIOLOGICAL
ALGAE: Water years 1989-90, 1996-97.
GAGE - Water-stage recorder and satellite telemeter. Datum of gage is 452.77 ft above NAVD of 1988. October 1919, to January 1935, nonrecording gage at site at Morris, 16.6 mi upstream, at datum 25.59 ft higher. January 1935 to September 1939, water-stage recorder 300 ft downstream from Morris site at that datum. October 1939, to September 2002, water-stage recorder at current site at datum 10 ft. higher.
EXTREMES OUTSIDE PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE: Flood of May 6, 1892 reached an estimated discharge of 72,500 ft³/s, stage not determined. A stage of 26.2 ft at Morris occurred in 1831, discharge not determined. A stage of 35.4 ft (ice jam) occurred at present site and datum on Jan. 21, 1916, estimated discharge, 40,000 ft³/s.
EXTREMES FOR PERIOD OF RECORD -
SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 106,000 ft³/s, May 19, 2020, gage height, 28.32 ft; minimum daily discharge, 461 ft³/s, Nov. 21, 2002, due to temporary dam closure.
SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 1,050 mg/L, Jan 9, 2008; minimum daily, 6 mg/L, Jan. 28-Feb. 6, 2004.
SUSPENDED-SEDIMENT LOADS: Maximum daily, 209,000 tons, Jan. 9, 2008; minimum daily, 37 tons, Feb. 4, 2004.