LOCATION.-- Lat 41°20'48", long 88°11'11" (NAD of 1927), in NW1/4NW1/4 sec. 15, T.33 N., R.9 E., Will County, Hydrologic Unit 07120001, on right bank, 0.4 mi downstream from Prairie Creek, 0.5 mi upstream from bridge on Interstate 55, 5 mi downstream from Wilmington, and at mile 5.7.

DRAINAGE AREA.-- 5,150 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: February 1935 to current year. Monthly discharge only for some periods, published in WSP 1308. November 1914 to September 1933 at site 8.5 mi upstream, published as Kankakee River at Custer Park. Records may not be equivalent.

STAGE: Water years 1994 to current year.

SURFACE-WATER QUALITY

CHEMICAL: Water years 1977-91. Additional chemical data for water years 1959-77 are published in Water Resources Investigations 78-23 and 79-24 as site F 01.

SEDIMENT: October 1978 to September 1982, January 1993 to December 1995.

WATER TEMPERATURE: Water years 1973-77.

REVISED RECORDS.-- WDR IL-75-1: Drainage area. WDR IL-83-2: 1982(M). WDR IL-91-2: 1981(M).

GAGE.-- Water-stage recorder and U.S. Army Corps of Engineers satellite telemeter. Datum of gage is 510.86 ft above NGVD of 1929. However, datum incorrectly published as 511.10 ft above NGVD of 1929 from Feb. 16, 1935 to Sept. 30, 1953.

REMARKS.-- Slight diurnal fluctuation at low flow caused by powerplants upstream from station.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 75,900 ft³/s, July 13, 1957, gage height, 11.40 ft; maximum gage height, 13.88 ft, Jan. 30, 1968, ice jam; minimum discharge, 204 ft³/s, Aug. 1, 1936.

SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 2,180 mg/L, Apr. 14, 1981; minimum daily, 5 mg/L, Feb. 5, 1993, Sept. 24-30, 1995, Oct. 12, 1995.

SUSPENDED-SEDIMENT LOADS: Maximum daily, 172,000 tons, Apr. 14, 1981; minimum daily, 12 tons, Sept. 20, 29-30, 1995.

EXTREMES OUTSIDE PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Floods in 1883, 1887 reached a stage of 16.7 ft, discharge not determined.