USGS Water-Year Summary 2024

05389500 Mississippi River at McGregor, IA

LOCATION - Lat 43°01'37.3", long 91°10'21" referenced to North American Datum of 1927, in SE 1/4 NE 1/4 SE 1/4 sec.22, T.95 N., R.3 W., Clayton County, IA, Hydrologic Unit 07060001, on right bank in city park at east end of Main Street in McGregor, 2.6 mi upstream from Wisconsin River, 4.3 mi downstream from Yellow River, and 633.4 mi upstream from Ohio River.

DRAINAGE AREA - 67,500 mi².

REVISIONS HISTORY - WDR IA-75-1: 1974. WDR US-2009: 2002.

SURFACE-WATER RECORDS

PERIOD OF RECORD - Discharge records from August 1936 to September 2005, October 2007 to September 2013; stage-only records from October 2005 to September 2007, October 2013 to current year.

GAGE - Water-stage recorder. Datum of gage is 604.50 ft above North American Vertical Datum of 1988. Auxiliary gage at Lock and Dam 9 (station 05388410), 14.1 mi upstream, at datum 5.30 ft lower. Prior to June 1, 1937, and since June 2, 1939, auxiliary water-stage recorder; June 1, 1937, to June 1, 1939, non-recording auxiliary gage. 

 

REMARKS - Accuracy of records is discussed in the annual Station Analysis archived at the USGS IA Water Science Center.

EXTREMES OUTSIDE PERIOD OF RECORD - Since at least 1828, no flood outside the period of record exceeded that of April 24, 1965, discharge, 276,000 ft³/s, gage height, 25.38 ft.

WATER-QUALITY RECORDS

PERIOD OF RECORD - Water years 1975-2004.

PERIOD OF DAILY RECORD -
SPECIFIC CONDUCTANCE: Daily instantaneous values collected in conjunction with suspended-sediment samples, July 1975 to September 2004, records fragmentary.
WATER TEMPERATURES: Daily instantaneous values collected in conjunction with suspended-sediment samples, July 1975 to September 2004, records fragmentary.
SUSPENDED-SEDIMENT CONCENTRATION AND DISCHARGE: July 1975 to September 2004.