SIOUX CITY, Iowa (KCAU) — Northern Siouxland saw a lot of snow this winter, and with temperatures on the rise really quickly, that has led to a lot of quick snowmelt in northern areas over the last few weeks. This is leading to rising river levels, causing parts of the Big Sioux River to have some flooding occur.
The Big Sioux River above Hawarden, Iowa, is currently at approximately 21.7 feet as of Monday afternoon and is expected to rise over the next few days. We are already past the flood stage, which is at 20.5 feet. It is expected to reach a moderate flood stage late Tuesday morning, which is at 24.0 feet. It is also expected to stay above moderate flood stage for a few days, peaking at around 24.4 feet on Thursday, before gradually falling.
The flood stage should drop below moderate flood stage this upcoming weekend or early next week, pending no major rainfall. Agricultural flooding has begun on the South Dakota side of the river, and some farmhouses on the South Dakota side of the river may be isolated by high water.
This will be the biggest crest we have seen for this area since it crested at 32.42 feet on September 15, 2019. It also crested at 35.2 feet on March 15, 2019, the only other time it crested higher was June 22, 2018, meaning this is expected to be the 4th highest flood stage for the Big Sioux River above Hawarden, Iowa.
The Big Sioux River at Akron, Iowa will also be seeing some flooding, but not as significant as we will see later this week. We are currently at 15.4 feet as of Monday afternoon, which is below the minor flood stage at 16.0 feet. It is expected to climb above Minor Flood Stage later Monday night or very early Tuesday morning. It is expected to climb above moderate flood stage, which is at 18.0 feet around midday Tuesday and will climb to a crest of around 18.3 feet, also expected on Thursday before slowly falling.
Impacts from this could mean some minor flooding of the lowest-lying areas along the river, with some rural roads on the South Dakota side of the river, and several farm levees could be overtopped with significant flooding of agricultural lands. Around 6,500 acres of farmland are expected to be flooded. This flood is not as historical as in Hawarden but is expected to be the first time in Moderate Flood Stage since it crested to 23.94 feet back on March 16, 2019. However, this is not uncommon as it will only be the 36th-highest crest reported.