Flash Flood — Harrison, Iowa

2007-05-05 to 2007-05-06 · near Missouri Vly, Harrison, Iowa

Event narrative

Rainfall of 5 inches fell across the Missouri Valley area Saturday May 5th prompting the levee along Willow Creek to eventually fail causing substantial flash flooding in and around the Missouri Valley area.

Initally flash flooding was observed due to the heavy rain Saturday evening the 5th near Highway 30 and county road 66. The levee failure caused more substantial flash flooding early Sunday the 6th with many residents barely able to escape the rising flood waters. The area most affected was the southwest part of town, which sat below the bluffs where most of the town is located. At least 77 homes and 6 businesses were flooded and declared an almost complete loss. Many vehicles were also flooded or severely damaged. Interstate 29 was closed for a while near town, along with Highway 30 and other local roads. The high water continued in the area well into the following week. It was estimated that road repair alone would cost several million dollars. Although homes in the higher sections of town escaped flood waters from the levee break, many sustained damage due to flooded basements, mudslides or basement walls caving in. The flooding prompted schools to be closed on Monday May 7th.

Wider weather episode

A warm front that was along the Kansas and Nebraska border early Saturday morning May 5th, lifted north during the day bringing widespread heavy rain and severe weather, including tornadoes, to eastern Nebraska and southwest Iowa. The warm front was part of a large upper level system that brought several days of severe weather and flooding to the region.

Heavy rain and flooding was reported with some of the activity Saturday morning, along with isolated severe thunderstorm reports. However, during the afternoon the severe weather became more widespread over northeast Nebraska where supercells spawned several tornadoes. At this time, thunderstorms, some severe with heavy rain, produced flash flooding over parts of southeast Nebraska. By evening much of the severe weather, including supercell producing tornadoes, shifted into southwest Iowa, although isolated severe thunderstorms persisted over parts of eastern Nebraska until after midnight CDT.

View location on OpenStreetMap → (41.5600, -95.9000)

Source: NOAA Storm Events Database, event_id 20262. Narrative written by the NWS forecast office that issued the report.