PIERRE — South Dakota Department of Transportation says its crews have been working to create a barrier barrier along the westbound lanes of Interstate 90 — just east of Exit 357 to Bridgewater — to divert the flood waters from continuing to overtop the interstate.

Traffic will still be reduced to one lane each direction east of Exit 357 to allow crews to continue monitoring and managing water levels as necessary to keep the roadway clear. Flagging operations will no longer be utilized.

The westbound off-ramp at Exit 357 will remain closed due to high water levels over the ramp.

The department said that drivers should be alert to changing conditions, standing water in the median and along the shoulders, suddenly slowing and merging traffic, and workers and equipment adjacent to the roadway.

The interstate was closed on Sept. 12 and 13 due to water covering the road between Mitchell and Sioux Falls. Since then, DOT personnel had been monitoring the flooded areas and allowing traffic to travel through the water.

In an address that responded to the flood conditions, Gov. Kristi Noem said this week that the interstate flooding was unprecedented, and said she would ask the state’s transportation leaders to “ensure that our interstates are never again closed for flooding.”

“We just can’t have that happen,” Noem said. “Our population is spread out. When we lose the ability to travel on interstates and major highways due to flooding, we are compounding the disaster.