LOCATION.-- Lat 41°31'20", long 88°11'33" (NAD of 1927), in SE1/4SW1/4 sec.10, T.35 N., R.9 E., Will County, Hydrologic Unit 07120004, on left bank 400 ft upstream from bridge on U.S. Highway 52 at Shorewood, 3.8 mi downstream from Lily Cache Creek and at mile 10.6.

DRAINAGE AREA.-- 324 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: October 1940 to current year. Published as "at Troy" 1940-65.

STAGE: Water years 1994 to current year.

SURFACE-WATER QUALITY

CHEMICAL: Water years 1978-91.

WATER TEMPERATURE: Water years 1964-76.

MISCELLANEOUS: Water years 1998 and 2002.

REVISED RECORDS.-- WSP 1035: 1944. WSP 1055: 1942(M). WDR IL-75-1: Drainage area.

GAGE.-- Water-stage recorder, phone telemeter, U.S. Army Corps of Engineers satellite telemeter, and masonry dam. Datum of gage is 564.62 ft above NGVD of 1929 (Illinois Department of Transportation bench mark) (564.32 ft NAVD 1988). Prior to Apr. 11, 1941, nonrecording gage at same site and datum.

REMARKS.-- Streamflow contains effluent from sewage-treatment plants upstream.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 17,300 ft³/s, July 18, 1996, from rating curve extended above 14,000 ft³/s, gage height, 14.03 ft, from floodmark; minimum 0.2 ft³/s, Nov. 17, 1955, result of freezeup.