As rivers keep rising, flooding is likely to get worse on Monday and Tuesday in Minnesota, South Dakota, and Iowa. Heavy rains ranging from 10 to 18 inches have been falling throughout portions of the Mississippi and Missouri River basins since Thursday, causing flooding.
A railroad bridge linking South Dakota and Iowa fell as part of the extensive flood devastation. Devastating floods in South Dakota have caused extensive damage to houses and infrastructure, as well as the collapse of a crucial bridge. South Dakota Governor Kristi L. Noem announced on Sunday that floods in the state were responsible for at least one death. A large number of residences in North Sioux City, S.D., were devastated by the sudden rush of floodwaters that occurred within thirty minutes.
Prior to Thursday’s and Saturday’s storms, which were fuelled by strong precipitation from the Gulf of Mexico, the soils had already been saturated by months of wetter-than-average weather. The saturation caused water to dash into rivers and streams, overflowing levees in several places. When they reach their crests on Tuesday or Wednesday, the rivers could reach moderate to record flood levels.
Although the soils are still moist, the streamflows are much above average, indicating that there is little ability to retain more precipitation. A more significant increase in the likelihood of flooding will result from each successive wave of precipitation.
Temperatures have been fluctuating around the nation for the last week, with Monday’s high humidity making it seem like almost 110 degrees in the Upper Midwest. Forecasts call for temperatures to peak in the 90s. If the Blue Earth River floods, “Imminent failure” might happen at the Rapidan Dam close to Mankato, Minnesota.
Part of Interstate 29 was temporarily closed among several roads due to flooding in the area. Major flooding set up on Monday over the Missouri River basin, affecting rivers in South Dakota (James, Vermillion, and Big Sioux), southwest Minnesota (Des Moines), and northwest Iowa (Little Sioux). Those regions were under a flood warning until further notice, while the upper Mississippi River in Wisconsin and Minnesota was under a flood watch.
