On Main Street in Rock Valley, Joane Rozeboom and her daughter, Britney Westra, watched as a tractor with a bucket and claw picked up mangled goods — cowhide furniture, drywall, insulation, flood-soaked clothing in plastic tubs — from outside their boutique, Copper Rose Apparel.

The shop had been a dream that they brought to life two years ago with help from their Covid-19 stimulus checks. As they looked at the destruction on Monday, they said they would work to reopen the boutique.

“We’re like, yep, we’re doing it, and it’s going to be not as much work as the first time,” Ms. Rozeboom said. “But the more we dig, the more we find it’s still going to be a lot of work.”

Elsewhere in Rock Valley, where the retreating water left behind a swampy stench on Monday that lingered in the 90-degree heat, the Blieks, the couple who struggled to reach safety on Saturday, took in the damage at their house.

Mud coated a tangle of recliners, mattresses and end tables. It was a total loss.

But on a mantel in a lower level of the home, they found undisturbed the urn holding the ashes of their daughter, Halee, who died after a car accident last year at the age of 35.

“When we got here, I said, ‘Randy, we’ve got Halee,’” Ms. Bliek said. “It was the only thing I was really concerned about.”

Lauryn Higgins contributed reporting from North Sioux City, S.D.