Event narrative (NOAA)
Record flooding on the Maquoketa River resulted in the failure of the earthen berm on the south side of the Lake Delhi/Hartwick Lake dam during the late morning and afternoon of July 24. The dam failure resulted in flash flooding of residences along the Maquoketa River immediately downstream of the dam, including portions of Hopkinton. In addition, the dam failure emptied out the 9 mile stretch of the Maquoketa River that constituted Lake Delhi/Hartwick Lake.||In Hopkinton, a few homes, several garages, outbuildings, parks and roads flooded. ||By the time the flood waters reached Monticello, the flood wave from the dam failure had largely been absorbed in the larger crest due to the ongoing record flooding of the Maquoketa River.||Please see the Storm Data narrative for the record floodi
Other notable flash flood events in Iowa
Source: NOAA/NCEI Storm Events Database. Deaths and injuries are those NOAA classifies as direct. Damage is the reporting office's estimate at the time and is not inflation-adjusted. This is a catalogue record, not a forecast.