The Airport in the Middle of a Bay

Osaka Kansai Airport is located on an artificial island in the middle of Osaka Bay. Two mountains were flattened to build the island and at $20 billion is the most expensive engineering project to date. It consists of two terminals, with Terminal 1 being the longest airport terminal in the world at just over a mile long. Thanks to some incredible engineering, it has been proven to withstand earthquakes and typhoons. There’s just one problem: the island is sinking faster than expected, leading to increasing problems with flooding. Since it opened in 1994, Kansai has sunk 38 feet. The islands were predicted to evenly settle over a 50-year period before stabilizing at 13 feet above sea level. That’s the minimum elevation required to prevent flooding in case a breach develops in an encircling seawall. Portions of the first of the two islands created reached that threshold within 6 years. At least $150 million was spent to raise the seawall, but some engineers predict that by 2056, sections of the two artificial islands may sink 13 more feet — to sea level. It has been expensive to keep Kansai International Airport high and dry, but the airport has done its job: to connect Osaka to the world. In 2016, more than 26 million passengers used Kansai, making it one of the 30 busiest airports in Asia. In 2001, the airport was honored by the American Society of Civil Engineers as one of the civil engineering monuments of the millennium. Still, an engineering miracle is no match for Mother Nature.