USGS Water-Year Summary 2020
05465500 Iowa River at Wapello, IA
LOCATION - Lat 41°10'41", long 91°10'55" referenced to North American Datum of 1927, in NW 1/4 SE 1/4 SE 1/4 sec.27, T.74 N., R.3 W., Louisa County, IA, Hydrologic Unit 07080209, on right bank 1,200 ft downstream from bridge on State Highway 99, at eastern edge of Wapello, 13.9 mi downstream from Cedar River, and 15.2 mi upstream from mouth. Sediment samples collected by boat in vicinity of gage.
DRAINAGE AREA - 12,500 mi².
- WSP 1308: 1917, 1923-1930, 1932. WSP 1438: Drainage area. WSP 1558: 1918, 1923-1925(M), 1929. WSP 1708: 1955(P), 1956.
PERIOD OF RECORD - Discharge records from October 1914 to current year. Prior to March 1918, monthly mean discharge for some periods published in WSP 1308.
GAGE - Water-stage recorder. Datum of gage is 538.17 ft above National Geodetic Vertical Datum of 1929. Prior to April 16, 1934, non-recording gage; prior to October 1, 1972, at datum 10.00 ft higher.
EXTREMES OUTSIDE PERIOD OF RECORD - Maximum discharges, 88,700 ft³/s, June 3, 1903, and 73,800 ft³/s, April 2, 1906.
PERIOD OF RECORD - Water years 1978 to current year.
PERIOD OF DAILY RECORD -
NITRATE + NITRITE: June 2009 to current year, records fragmentary.
SPECIFIC CONDUCTANCE: Daily instantaneous values collected in conjunction with suspended-sediment samples, January 1978 to September 2006, October 2009 to September 2010, records fragmentary. Beginning October 2010, daily instantaneous values published in combined water-quality table.
WATER TEMPERATURE: Daily instantaneous values collected in conjunction with suspended-sediment samples, January 1978 to September 2006, records fragmentary. Beginning October 2010, daily instantaneous values published in combined water-quality table. Daily mean, October 2011 to current year, records fragmentary.
SUSPENDED-SEDIMENT CONCENTRATION AND DISCHARGE: April 1978 to September 2006, October 2009 to current year, records fragmentary for some periods.