LOCATION.-- Lat 41°26'32", long 90°33'21" (NAD of 1927), in NW1/4NE1/4 sec.25, T.17 N., R.2 W., Rock Island County, Hydrologic Unit 07090005, on right bank 100 ft. upstream from Knoxville Road Bridge, 1 mi southeast of Milan, and at mile 1.2.

DRAINAGE AREA.-- 62.4 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: October 1939 to September 1940 (fragmentary), July 1941 to September 1986. Seven-month period (March to September), water years 1987-89. March 1989 to current year.

STAGE: Water years 1999 to current year.

REVISED RECORDS.-- WSP 1308: 1940(M), 1943(M). WDR IL-72-1: Drainage area.

GAGE.-- Water-stage recorder, phone telemeter, and crest-stage gage. Datum of gage is 565.23 ft above NGVD of 1929 (levels by U.S. Army Corps of Engineers) (565.01 ft NAVD 1988). Prior to Oct. 1, 1987, at datum 1.00 ft higher. Prior to Apr. 5, 1940, nonrecording gage at site 300 ft upstream. Oct. 1939 to Nov. 15, 1984, recording gage at site 400 ft. upstream.

REMARKS.-- Occasional pumpage of about 3-6 ft³/s from quarry into creek upstream from gage.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 9,300 ft³/s, Apr. 22, 1973, gage height, 12.65 ft, present datum; no flow at times in several years.

EXTREMES OUTSIDE PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Flood of June 1936 reached a stage of 7.4 ft, from information by local residents, and an estimated discharge of 4,500 ft³/s.