LOCATION.-- Lat 42°15'10", long 90°17'09" (NAD of 1927), in NE1/4NW1/4 sec.16, T.26 N., R.2 E., Jo Daviess County, Hydrologic Unit 07060005, on right bank, 0.3 mi southwest of Hanover, and at mile 13.9.

DRAINAGE AREA.-- 247 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: October 1934 to current year. Monthly discharge only for some periods, published in WSP 1308.

STAGE: Water years 1994 to current year.

SURFACE-WATER QUALITY

SEDIMENT: October 1994 to September 1997.

MISCELLANEOUS: Sediment concentration and particle size, water year 1997.

REVISED RECORDS.-- WSP 1005: 1939, 1941(M). WSP 1308: 1935-38(M), 1943-45(M). WDR IL-75-1: Drainage area.

GAGE.-- Water-stage recorder and phone telemeter. Datum of gage is 591.00 ft above NGVD of 1929 (590.87 ft NAVD 1988). Prior to Oct. 1, 1945, nonrecording gage at site 3.5 mi downstream at datum 9.48 ft lower.

REMARKS.-- Occasional regulation during low flow by dam at Hanover. Suspended-sediment samples were collected by a local observer once a week with additional samples collected during storm runoff periods.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 13,700 ft³/s, June 4, 2002, gage height 27.91 ft; no flow for part of each day, May 23, 24, 1967, result of temporary closure of gate at dam at Hanover.

SUSPENDED-SEDIMENT CONCENTRATIONS: Maximum daily, 3,790 mg/L, May 28, 1996; minimum daily, 5 mg/L, Aug. 5, 1997.

SUSPENDED-SEDIMENT LOADS: Maximum daily, 28,900 tons, May 28, 1996; minimum daily, 0.8 tons, Aug. 5, 1997