Fans of “Project Runway” are familiar with the phrase “one minute you’re in, the next minute you’re out,” as a panel of celebrities determines who goes home and who stays for another round. Five hundred forty Ann Arbor property owners received their own shakeup in February as an arduous process to redefine the boundaries of the city’s floodplains was finally concluded. City officials say the new map “resembles” the old one completed in 1992, though new technology provides greater accuracy.

This is a map no one wants to be on, because residents in a floodplain can’t get mortgages unless they buy federal flood insurance. “We’re not high flyers with beachfront properties or owners of ­multimillion dollar mansions built on questionable turf,” grumbles one homeowner on the Old West Side. He says he pays close to $2,000 annually for flood insurance, over and above the cost of his regular homeowners insurance.

Happily, the new maps place fewer homes in flood zones. Eighty-eight residential properties are newly in, but 204 others are now out. You can see which lots’ statuses changed on a nifty online map at www.a2gov.org/floodplains.

Flood insurance is mandated only for properties whose mortgages are guaranteed by the federal government, but these days, that’s nearly all of them. So for many homeowners, lenders will be the ones who determine how much protection is needed—giving a whole new meaning to a property being underwater.