05536123 CHICAGO RIVER AT COLUMBUS DRIVE AT CHICAGO, IL
LOCATION.--Lat 41°53'18", long 87°37'16", in NE¼SW¼ sec.10, T.39 N., R.14 E., Cook County, Hydrologic Unit 07120003, on left downstream side of bridge within the Columbus Drive bridge structure in Chicago, 0.5 mi downstream from Chicago River Lock and Dam.
DRAINAGE AREA.--Indeterminate.
PERIOD OF RECORD.--December 1996 to current year.
GAGE.--Acoustical flowmeter. Datum of gage is 579.48 ft above sea level (Chicago City datum).
REMARKS.--This gaging station provides flow data to determine Illinois' diversion of Lake Michigan water.
A U.S. Supreme Court Decree limits Illinois' diversion to an average of 3,200 ft3/s. Illinois' diversion
includes water diverted from the lake for domestic water supply, for navigation, and water-quality improvement
in the Chicago Sanitary and Ship Canal system, and stormwater runoff from a 673 mi2 diverted watershed
area. Gage-height telemeter at station.