LOCATION.-- Lat 41°49'21", long 88°10'24" (NAD of 1927), in SW1/4NE1/4 sec.35, T.39 N., R.9 E., Du Page County, Hydrologic Unit 07120004, on right bank 400 ft upstream from Warrenville Forest Preserve Dam in Warrenville, 0.6 mi downstream from Spring Brook, and at mile 38.9.

DRAINAGE AREA.-- 90.4 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: October 1968 to current year.

STAGE: Water years 1994 to current year.

SURFACE-WATER QUALITY

CHEMICAL: Water years 1977-91.

REVISED RECORDS.-- WDR IL-75-1: Drainage area.

GAGE.-- Water-stage recorder, phone telemeter, crest-stage gage and masonry dam. Datum of gage is 688.59 ft above NGVD of 1929 (Illinois Department of Transportation bench mark).

REMARKS.-- Flow slightly regulated by sewage- treatment plants upstream.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 3,470 ft³/s, July 18, 1996, gage height, 6.41 ft; minimum daily discharge, 7.8 ft³/s, Sept. 14, 1971, Oct. 26, 1972.

EXTREMES OUTSIDE PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Flood of Oct. 11, 1954, reached a stage of 5.54 ft, from floodmark, discharge not determined.