Some, who had reconciled themselves to gutting their homes, now wonder whether they will have to tear them down altogether after so much time underwater. Others say they may never rebuild.

“We still have about four feet,” John Denson, 40, said one recent afternoon of his house in Nottingham Forest. “The news is: Recovery begins. That’s not happening here.”

Until the water goes down, residents said, they cannot start recovering, rebuilding or meeting with the Federal Emergency Management Agency or insurance agents. At most, people said, they wade or boat back home to check on the mold that now wallpapers everything, and to drag a few more keepsakes out through the upstairs windows.

On Thursday morning, Ms. Thomason, her husband and family set off at 6:30 a.m. from the hotel where they are staying until they move into a rental house. They caravanned home with two boats and a trailer, but on street after street, they were turned back by roadblocks and police officers warning them about the soaring levels of contaminants in the water.

Normal things felt bizarre to her. When they parked on the side of a residential street to plot their next move, Ms. Thomason gawked as a landscaping crew drove by.

“Are you kidding me?” she said. “Half the neighborhood’s getting their lawn done, and the other half wants to go boating in.”

Eventually, they found a way in. They launched two boats into the murk and puttered into Thornwood, toward the sodden two-story home they now plan to tear down and never rebuild.