Kansai International Airport is located on a man-made island in
Osaka Bay, serving the Osaka area. It was constructed at a cost of over $14 billion US, beginning in
1986. It opened for flights in
1996, but construction continues. At approximately 4 X 1 km, the island is constructed in around 18m of water, entirely from
landfill. These stats make it the largest man-made island (and the largest landfill) in the world. The main
terminal building, at approx. 1.6 km in length, is the world's longest.
Construction is continuing on a second runway; however, problems with the original construction make the completion date and cost uncertain. Actually, Kansai Airport is settling into the seafloor at just under one foot per year, more than six times as fast as had been predicted. There have already been problems with high waves and rain overtaxing the drainage capability of the island due to the lower falloff. The jacks were primarily designed to keep the structures level, not to compensate for rapid sinking of the landfill. What will be done about this remains to be seen.
Kansai's problems are compounded by lower-than-expected utilization (and therefore revenues) since its opening. In 2000, according to CNN, Kansai International handled around 123,000 flights. Its maximum rate is around 160,000. While that alone wouldn't be a low enough level to cause trouble, the cost of additional repairs and construction (including an unplanned below-surface seawall to prevent seepage) have added costs to the project. The seawall apparently added approximately 8% to 10% to the total, and was debt-financed. Finally, the air travel market in the Osaka region is primarily an economy travel one. The lack of business and first-class passengers using the hub is further cutting into revenue.
Some critics say that the depth of the water (18-20m) and resultant engineering demands are to blame. Other projects on reclaimed land, including an airport near Inchon, Korea, and the Chek Lap Kok airport in Hong Kong, are doing better. They were both built in shallower (1-5m) waters.