The operator of the Kansai International Airport has failed to prevent flooding due to a storm surge once again, despite measures it took because of similar damage in the past.
The hub airport in western Japan is located on an artificial island in Osaka Bay. It has 2 runways, each with a terminal building.
Typhoon Jebi's surge on Tuesday hit mainly the older Runway A, which opened in 1994. The runway has been plagued with the problem of land sinking due to its weak foundation.
Usually most of Runway A is only about 1 to 2 meters above the sea level, and officials from the operator Kansai Airports say it was submerged by up to 50 centimeters by Jebi.
Officials say Runway A's reclaimed land has sunk more than 4 meters in one place since its opening.
In 2004, it was inundated when an approaching typhoon triggered a storm surge and high waves.
The operator has raised the level of the tide wall to about 5 meters above sea level.
The company previously claimed the elevated wall would protect Runway A from the strongest storm surges that have ever hit the area, as well as from huge waves that are likely come only once in 50 years.
An airport official said on Wednesday typhoon Jebi was more powerful than they had expected and cited the need to take additional measures.
Runway B, which was completed 13 years after Runway A, has an elevation of at least 4.6 meters above sea. The operator says it has experienced no major flooding damage.