LOCATION.-- Lat 42°32'25", long 90°38'42" (NAD of 1927), in NE1/4NW1/4, sec.30, T.89 N., R.3 E., Dubuque County, IA, Hydrologic Unit 07060005, on right bank at foot of Fourth Street in Dubuque, IA, 20 ft downstream from a railroad bridge, and at mile 579.9.

DRAINAGE AREA.-- 81,600 mi².

PERIOD OF RECORD.--

STAGE: January to February 1995, April to November 1995, January 1996 to September 1997. Gage-height record for Oct. 1, 1873 to current, with the exception of gaps during winter periods in the early years when the gage was not read, available in files of U.S. Army Corp of Engineers.

GAGE.-- Water stage recorder, U.S. Army Corps of Engineers satellite telemeter, and three staff gages. Datum of gage is 585.47 ft above NGVD of 1929 (levels by U.S. Army Corps of Engineers) (585.34 ft NAVD 1988).

REMARKS.-- River is regulated by the Corps of Engineers at L&D #11 upstream from the gage and at L&D #12 in Bellevue, IA, downstream from the gage.

EXTREMES FOR PERIOD OF RECORD.--

STAGE: Maximum gage height, 28.01 ft, Apr 16-17, 1997; minimum, 12.23 ft, Sep. 14, 1996.

EXTREMES OUTSIDE PERIOD OF RECORD.--

STAGE: Maximum flood prior to 1970 reached a stage of 26.81 ft, Apr. 26, 1965.