NORTH SIOUX CITY, SD (KTIV) – South Dakota state officials have released information showing what they believe would have happened without the construction of a levee in North Sioux City.

North Sioux City, particularly the area around McCook Lake, was hit by extreme flooding on Sunday, June 23, damaging dozens of homes. According to the South Dakota Flood Information System models below, the flooding could have been much worse if an additional levee had not been constructed on Sunday, June 23. These models show that without this levee, almost all of North Sioux City would have been inundated.

The office of South Dakota Governor Kristi Noem stressed that large parts of North Sioux City were only saved from flooding thanks to this additional levee.

In addition to this information, the governor's office released a timeline for the state's response to flooding in southeastern South Dakota. The full timeline is below, but here are some of the key points:

• The South Dakota Emergency Management Agency contacted counties on Friday, June 21, to see if there was any damage from the heavy rain and if any requests for assistance had been received. Governor Noem is also meeting with the U.S. Army Corps of Engineers.
• On Saturday, June 22, authorities learned that the Big Sioux River was expected to reach 38.4 feet, while the previous record was 37.7 feet.
• Starting at 6 p.m. Sunday, the South Dakota Department of Transportation will close I-29 while 40 Department of Transportation employees work on the levee and traffic plan, removing barriers and marking flood areas.
• According to the timeline, officials believe a text message warning of rising water levels was sent to McCook Lake residents at 8:21 p.m.
• At around 10:30 p.m. on Sunday, the Big Sioux River crested at 44.98 feet, 7.28 feet above the record, 2.77 feet higher than forecast the previous day and 12 hours earlier than expected.

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