LOCATION.-- Lat 41°09'36", long 87°40'07" (NAD of 1927), in SW1/4NE1/4 sec.24, T.31 N., R.13 E., Kankakee County, Hydrologic Unit 07120001, on right bank at end of Hill Street in Momence, 0.2 mi downstream from bridge on State Highways 1 and 17, 1.2 mi upstream from Tower Creek, and at mile 47.9.

DRAINAGE AREA.-- 2,294 mi², of which 201 mi² probably is noncontributing.

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: February to December 1905, February to July 1906, December 1914 to current year.

STAGE: Water years 1994 to current year.

SURFACE-WATER QUALITY

CHEMICAL: Water years 1975-1991 and 1999 to current. Additional chemical data for water years 1959-72 are published in Water-Resources Investigations 78-23 and 79-24 as site F 02.

SEDIMENT: October 1978-September 1981, January 1993-December 1995.

MISCELLANEOUS: Contaminants in streambed sediments, August 1998; Contaminants in fish tissue, August 1998.

BIOLOGICAL

ALGAE: Pigment and biomass, Water years 1989 and 1990.

BENTHIC MACROINVERTEBRATES: Water year 1999.

FISH: Water year 1999.

HABITAT: Water year 1999.

REVISED RECORDS.-- WSP 1238: 1916, 1930. WSP 1308: 1915(M), 1917(M), 1919(M), 1922(M), 1926(M), 1934-35(M), 1938(M). WDR IL-75-1: Drainage area.

GAGE.-- Water-stage recorder, U.S. Army Corps of Engineers satellite telemeter. Datum of gage is 609.18 ft above NGVD of 1929. Prior to Aug. 1, 1938, nonrecording gage at site 0.2 mi upstream at datum 1.00 ft higher. Aug. 1, 1938, to Aug. 8, 1969, water-stage recorder at present site at datum 1.00 ft higher.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 16,000 ft³/s, Mar. 6, 1979, gage height, 10.51 ft, ice jam; minimum, 243 ft³/s, Aug. 7, 1988.

SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 2,620 mg/L, June 9, 1981; minimum daily, 4 mg/L, Feb. 22, Apr. 30, May 3, 4, 1993.

SUSPENDED-SEDIMENT LOADS: Maximum daily, 30,600 tons, May 30, 1981; minimum daily, 23 tons, Nov. 23, 1980.