05536121 CHICAGO RIVER AT CHICAGO LOCK AT CHICAGO, IL
LOCATION.--Lat 41°53'18", long 87°36'27", in NE¼SE¼ sec.10, T.39 N., R.14 E., Cook
County, Hydrologic Unit 07120003, 0.2 mi east of Lake Shore Drive in Chicago, on left
downstream side of lock guidewall, 100 ft downstream of the river-side lock gates at
the Chicago River Lock and Dam.
DRAINAGE AREA.-- Indeterminate.
PERIOD OF RECORD.--September 1997 to current year.
GAGE.--Water-stage recorder. Datum of gage is 579.48 ft above sea level (Chicago City datum).
REMARKS.--This gaging station provides stage 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 for water-quality improvement in the Chicago Sanitary and Ship Canal
system, and for stormwater runoff from a 673 mi2 diverted watershed area. Gage-height telemeter at station.