The government has concluded that the period for landfill work must be extended to about 10 years from the initially planned five years for a project to relocate U.S. Marine Corps Air Station Futenma in Ginowan, Okinawa Prefecture, informed sources said Monday.
The expected extension means that the return of the current site where the Futenma base lies to Japan could be delayed into the 2030s at the earliest from the current plan of as early as fiscal 2022, after taking into account the three years needed to build facilities at a new site.
The government’s conclusion reflects the time needed to improve soft ground on the seafloor in an offshore area of the relocation site in the Henoko district in Nago, also in Okinawa, the sources said.
The Defense Ministry will report the new estimate on the period for landfill work to a meeting of experts in civil engineering and related fields as early as Wednesday, the sources said.
A delay in the relocation project will inevitably lead to larger costs than the current estimate of at least ¥350 billion.
The government, however, maintains the view that building a new base in Henoko is the only way to have the Futenma site returned and is poised to keep the project going.
The central government plans to file design changes for the ground improvement work early next year with the Okinawa Prefectural Government. Okinawa Gov. Denny Tamaki is expected to reject the plan.
If the central government takes the possible dispute with Okinawa to court, the completion of the project could be delayed further.
The Japanese and U.S. governments agreed in 2013 that the Futenma site could be returned to Japan as early as fiscal 2022 on condition that the functions of the air base are relocated to Henoko.
Following a court battle with Okinawa over approval for landfill work, the central government started placing soil in the offshore area in December last year. Some soft ground in the eastern part of the area for landfill work was then discovered.
The ministry’s Okinawa Defense Bureau is studying a plan to improve the ground in question by placing about 77,000 piles into the ground for reinforcement.