LOCATION.-- Lat 38°46'23", long 88°29'50" (NAD of 1927), in NW1/4SE1/4 sec.23, T.4 N., R.6 E., Clay County, Hydrologic Unit 05120114, on right bank at city of Louisville pumphouse, 0.5 mi downstream from county highway bridge, 0.7 mi downstream from Panther Creek, and at mile 159.0.

DRAINAGE AREA.-- 745 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: August 1965 to October 1982.

SURFACE-WATER QUALITY

CHEMICAL: Water years 1971 to 1991.

SEDIMENT: March 1971 to September 1981.

REVISED RECORDS.-- WDR IL-73-1: Drainage area.

GAGE.-- Water-stage recorder. Datum of gage is 420.51 ft above NGVD of 1929. Prior to Nov. 20, 1972, nonrecording gage at site 0.5 mi upstream at present datum.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 24,000 ft³/s Dec. 22, 1967, gage height, 31.00 ft; minimum daily, 0.5 ft³/s Oct. 5, 1967.

SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily mean, 2,320 mg/L June 3, 1980; minimum daily mean, 4 mg/L Jan. 12, 13, 1979.

SUSPENDED-SEDIMENT LOADS: Maximum daily, 29,900 tons Apr. 13, 1979; minimum daily, 0.10 ton Nov. 11, 1978.

EXTREMES OUTSIDE PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Flood of January 1950 reached a stage of 36.1 ft, present datum, at the U.S. Highway 45 crossing 0.5 mi north of Louisville and about 1.5 mi upstream from present site.