Flash Flood in Houston County, Minnesota

Very heavy rain led to flash flooding through much of the county. A rainfall total of 7.18 inches was measured 3 miles southwest of Reno. The bridge over Clear Creek was reported damaged and unsafe for use. In addition, highway 26 was closed due to mudslides. County Highways 5, 23, 31 and 249 were closed due to high water and washouts.

A warm front extended east to west across the Upper Mississippi Valley on June 7, which provided the focus for thunderstorms producing excessive rainfall. In fact, these storms exhibited very high rainfall rates, which led to 1 to 2 inch rainfall amounts in an hour or so. As the storms congealed into a larger scale line of thunderstorms, they continued to move over the same areas, which led to significant flash flooding through the evening and overnight.

On June 8, the warm front was lingering across the region, but a cold front was quickly tracking east out of the northern Plains. Showers and storms would redevelop during the day in the vicinity of the warm front, while a line of storms developed out ahead of the cold front, with these tracking across the region Sunday night. Again, copious amounts of moisture lead to periods of heavy rain.

The heavy rainfall on June 8 enhanced the already dangerous flooding conditions across parts of southeast Minnesota. Many roads were already closed from the June 7 rains due to water over the roadways, mudslides, or partial washouts. Conditions only worsened, leading to more road closures, sandbagging, and some evacuations.

While the rain was tapering off and moving east Sunday night, June 8, the rivers continued to rise, and some extremely quickly. Some rivers responded with a foot per hour rises. A top 5 record crest was set at the South Branch of the Root River at Preston.

Fillmore, Houston and Mower County were declared federal disaster areas. Damage to crops and infrastructure in these locations was preliminarily estimated at 25 to 35 million dollars.