May 1, 2009
Heavy rains during the last week of April resulted in the Iowa River at Marengo going above the moderate flood stage level of 15.5 feet on April 29th around 2 am. It crested around 17.64 feet around 9 pm April 30. It finally fell below the moderate flood stage level around 2 am May 7.
Source: NOAA National Weather Service Storm Events Database (event 170074). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Iowa County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.