Sand may seem like an infinite natural resource, but as cities with beaches around the world know all too well, it's anything but. And Miami Beach, Fla., is standing at a crossroads now that it, along with the US Army Corps of Engineers, has spent years pumping up sand from the seafloor to refill its receding beaches in a fight against rising sea levels that it ultimately can't win, reports the Verge in a lengthy feature. As far as that seafloor pumping goes in Miami Beach, the sand that could be pulled from the nearby ocean is all used up. That's because what's been brought to shore eventually washes back out, and most can never be reclaimed. "If it's sucked out past a certain depth, it’s scattered along the continental shelf, too dispersed to be gathered back," writes Josh Dzieza.
Dzieza digs into some of Miami Beach's options, both theoretical and tried: an inland mine; getting the sand off the counties to the north; buying premium sand from the Bahamas. But then there's the trouble of paying for sand. Without income tax in Florida, property taxes—and thus property values—need to continue rising even as the beaches are washing away. "The irony is ... the way to deal with rising sea levels is to build more condos," one expert says. But another notes that you can't have both buildings and beaches, and that there will soon be a rush to build seawalls to protect at-risk properties. Dzieza predicts a future shoreline that's "a fortress of concrete and rock," with our only beaches being pricey "amusement parks" maintained by sand piped in from a more extreme distance. Read the full piece for more on the rub with the Bahamian sand idea. (Read more sea level rise stories.)