USGS Water-Year Summary 2022
06600100 Floyd River at Alton, IA
LOCATION - Lat 42°58'55", long 96°00'03" referenced to North American Datum of 1927, in NW 1/4 NE 1/4 NE 1/4 sec.11, T.94 N., R.44 W., Sioux County, IA, Hydrologic Unit 10230002, on right bank 15 ft downstream from bridge on East Division Street in Alton, 34.3 mi upstream from West Branch Floyd River, and 55.3 mi upstream from mouth.
DRAINAGE AREA - 268 mi².
- WDR IA-82-1: Drainage area.
PERIOD OF RECORD - Discharge records from October 1955 to current year. Prior to December 1955, monthly mean discharge published in WSP 1730.
GAGE - Water-stage recorder. Datum of gage is 1,269.55 ft above National Geodetic Vertical Datum of 1929.
EXTREMES OUTSIDE PERIOD OF RECORD - Flood in June 1953, discharge about 45,500 ft³/s, from information by U.S. Army Corps of Engineers.