LOCATION.-- Lat 41°48'09", Long 88°04'40", in SW1/4SE1/4 sec.3, T.38 N., R.10 E., Du Page County, Hydrologic Unit 07120004, on downstream side of bridge on State Highway 53 at Lisle, 0.2 mi upstream from confluence with East Branch Du Page River.

DRAINAGE AREA.-- 11.8 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: December 1985 to September 1990.

PARTIAL RECORD: Annual maximum gage height, water years 1961-76.

PRECIPITATION: June 1986 to September 1991.

GAGE.-- Rain gage, Water-stage recorder and crest-stage gage. Datum of gage is 657.83 ft above NGVD of 1929 (657.56 ft NAVD 1988). October 1970 to September 1976, crest-stage gage at same site at datum 3.04 ft higher. October 1961 to September 1970, crest-stage gage at same site at datum 6.09 ft higher.

REMARKS.-- For precipitation records, snowfall-affected data can result during cold weather when snow fills the rain-gage funnel and then melts as temperatures rise. Snowfall-affected data are subject to appreciable errors.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 1,230 ft³/s, Aug. 14, 1987, gage height, 8.10 ft; maximum gage height, 10.63 ft, present datum, Dec. 30, 1972; no flow at times in most years.

PRECIPITATION: Maximum recorded, 3.78 in., May 9, 1990 but may have been greater during periods of missing record.