LOCATION.--Lat 42°34'19.2", long 92°37'05.8"
  referenced to North American Datum of 1983, in NW 1/4 SE 1/4 SE 1/4
  sec.28, T.90 N., R.15 W., Butler County, IA, Hydrologic Unit
  07080205, on right bank 5 ft downstream from bridge on County Highway
  T55, 0.2 mi north of New Hartford, and 9.9 mi upstream from mouth.
  (map)
  DRAINAGE AREA.--347 mi2.
  SURFACE-WATER RECORDS
  PERIOD OF RECORD.--Discharge records from October 1945 to current
  year. Prior to April 1948, monthly mean discharge for some periods
  published in WSP 1308.
  REVISED RECORDS.--WSP 1438: Drainage area. WSP 1558: 1948-49. WSP
  1708: 1947 (M).
  GAGE.--Water-stage recorder. Datum of gage is 882.44 ft above
  National Geodetic Vertical Datum of 1929. Prior to July 14, 1959,
  non-recording gage at same site and datum.
  WATER-QUALITY RECORDS
  PERIOD OF RECORD.--Water years 1988, 2001-2002, 2011-2012. Period
  of record includes water-quality data published in USGS annual
  reports and various project reports.