LOCATION.-- Lat 41°38'33", long 87°59'57" (NAD of 1927), in SW1/4SE1/4 sec.32, T.37 N., R.11 E., Cook County, Hydrologic Unit 07120004, on left bank at downstream side of bridge on State Street, 2 mi south of Lemont, and at mile 5.4.

DRAINAGE AREA.-- 20.9 mi².

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: July 1951 to current year.

STAGE: Water years 1994 to current year.

REVISED RECORDS.-- WSP 1338: 1952(M). WDR IL-75-1: Drainage area.

GAGE.-- Water-stage recorder and phone telemeter. Datum of gage is 637.20 ft above NGVD of 1929.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 5,310 ft³/s, July 18, 1996, from rating curve extended above 2,800 ft³/s, gage height, 11.10 ft; no flow at times in most years.

Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data