Kansai International Airport in Japan, one of the world's most ambitious and costly infrastructure projects, is sinking into the sea faster than engineers anticipated and could be submerged by 2056 if the trend continues, according to a report by The Mirror.
Opened in 1994 and constructed on an artificial island in Osaka Bay, the airport cost Japanese taxpayers more than $20 billion. Built atop a seabed largely composed of soft alluvial clay, engineers expected the ground to compress gradually over time. Initial projections predicted a 4-meter drop over 50 years. In reality, The Mirror reports that the island has already sunk approximately 13 meters — more than triple the original estimate.
Engineers were reportedly stunned by the disparity between their models and the actual subsidence. Yukako Handa, former communications director for the Kansai Airports authority, explained that the volume of infill was calculated based on an anticipated 50-year rate. But the island has continued to sink, even after the installation of sand drainage systems designed to stabilize the ground.
An additional $150 million was invested in reinforcing the airport's seawall, which has somewhat slowed the rate of subsidence. Nevertheless, updated forecasts suggest the facility could slip below sea level as soon as 2056 if the current pace persists.
The airport's low elevation also leaves it especially vulnerable to storms and earthquakes. In 2018, a typhoon flooded the runways and shut the airport down for two weeks. On other occasions, flooding has again disrupted operations, and in one instance, a 2,500-ton ship crashed into the bridge connecting the island to the mainland.
A perfect record for baggage handling
In stark contrast to its structural woes, Kansai International Airport has earned global acclaim for its operational excellence, particularly in baggage handling. In 2024 alone, nearly 26 million passengers passed through the airport, with around 170,000 takeoffs and landings. Notably, not a single bag has ever been reported lost since the airport began operating three decades ago, according to airport officials.
This spotless record has earned Kansai numerous international awards, including being named "World's Best Airport for Baggage Delivery" by Skytrax.
