Flood preparations are coming into place for a 100-year flooding event on the Big Sioux River.  

Governor Dennis Daugaard and Union County officials were in Elk Point Wednesday to reveal what measures will be taken.

One component includes shutting down Interstate 29 at Exit 4 on Thursday.  “The Department of Transportation, National Guard and local officials will be plugging the underpass for the four lanes of interstate (using) sandbagging protective measures so that the interchange will become part of the levee.”

The downside of that effort will be excess water flowing toward the community of McCook Lake while the existing levee will protect North Sioux City and Dakota Dunes.  No evacuation order has been given, but residents may choose to leave of their own volition.

A detour will be set up using Exit 26 on the north through Vermillion across the Newcastle Bridge into Nebraska then back east until reaching Sioux City.