The Iowa Flood Center’s Upper Iowa Hydrologic Assessment includes a breakdown of flood events in the UIR Watershed over the past 25 years, noting that flood events are consistently becoming more frequent as the watershed experiences more frequent heavy rainfall events. Table 2.2 in the Upper Iowa Hydrologic Assessment provides information on the historic crests of the UIR at the three river locations where the US Geological Survey (USGS) records stage, Dorchester, Decorah and Bluffton.
Each of the three large flooding events in the last ten years, June 2008, June 2013, and August 2016, were associated with 7–10 inches of rainfall over a one or two-day period. These floods disrupted travel, damaged farmland, homes and businesses and physically, emotionally, and financially impacted the Upper Iowa River Watershed residents. Over half of watershed residents who reported damage from flooding in the past five years reported moderate to severe flood damage to farmland. 28% percent reported moderate to severe damage to homes and 20% percent reported moderate to severe damage to businesses. Downstream residents were also impacted as floodwaters carried hazardous material and debris into fields and backwaters, impacting downstream farms and natural areas, water quality, and ecosystems in the UIR Watershed and the Mississippi River and its backwaters. Private and public properties, including county, state and federal lands were also impacted
In 2018, 89% percent of landowner respondents to the UIRW Survey agreed or strongly agreed that flooding is a problem in the UIRW and 80% disagree or strongly disagree that enough is being done in the UIRW to reduce flooding. Fine the full Upper Iowa River Watershed Landowner Survey here. The 2018 landowner survey captures public perceptions. The USGS measurements of Historic River Crests at three points on the UIR documents the actual river stage. The Dorchester gauging station is the furthest downstream. The Decorah gauging station is centrally located along the river corridor and the Bluffton gauging station is the furthest upstream of the three. Each is in Iowa.