The central government is expected to announce by year-end a revised overall cost projection and timetable for the relocation of the U.S. military’s Futenma base in Okinawa Prefecture after reassessing both.
The need for reassessment arose after “ground as soft as mayonnaise” was discovered in the planned reclamation area off the Henoko district of Nago in the prefecture, to which the Futenma facility will be relocated after land reclamation work in the sea is completed.
The project is expected to significantly exceed the initial time and cost estimates due to the need to strengthen the soft foundation.
The central government tentatively plans to apply to the Okinawa prefectural government early next year at the soonest to change the construction plan. To proceed with reclamation work in the section with weak ground, the government needs the approval of prefectural officials, who remain adamantly opposed to the relocation of the base within the prefecture.
The central government is pushing forward its plan to relocate U.S. Marine Corps Air Station Futenma in Ginowan to a landfill under construction off Henoko as the only option available.
PLEA TO HALT BASE PROJECT
On Sept. 29, Okinawa Governor Denny Tamaki made a fresh call to halt the U.S. base project when he met with new Defense Minister Taro Kono at the prefectural government building in Naha.
“Public opinion in Okinawa remains hard and fast against the work to reclaim waters off Henoko,” the governor said. “The central government should immediately suspend the reclamation and start a dialogue with the prefectural government.”
In reply, Kono said the reclamation off Henoko is being carried out to close the Futenma facility and return the land to islanders.
“We must achieve the relocation as early as possible,” he said, reiterating the central government’s stance and dismissing the governor’s request.
The existence of a soft seabed in the planned reclamation area was discovered during a 2014-2016 boring survey conducted by the Defense Ministry’s Okinawa Defense Bureau.
It disclosed the discovery in March 2018 only after a local group demanded details of the findings in a freedom of information request.
The central government proceeded with reclamation work in December that year, starting with a section outside the area with the soft seabed.
The overall cost of the project, which in 2014 then Defense Minister Itsunori Onodera said would cost at least 350 billion yen ($3.24 billion), will now likely increase substantially due to the extra work needed to reinforce the weak foundation.
A projection by the prefectural government estimated it would hit 2.55 trillion yen, including the stabilization work.
In addition, Tamaki argued that it is technically infeasible to carry out work of that magnitude.
However, after their 30-minute meeting on Sept. 29, Kono, who was visiting the southernmost prefecture for the first time as defense minister, downplayed concerns about the feasibility of the ground reinforcement work.
“I have been briefed that engineers have plenty of experience with the reinforcement method and the problem will be overcome with the method,” he told reporters. “As soon as we are ready, we will apply for the change to the plan.”
SOFT SEABED POSES MAJOR TEST
The soft seabed measures 65.4 hectares, 60 percent of the section on the side of Oura Bay, where reclamation work has yet to be started.
Japanese general contractors previously have conducted ground reinforcement only to a depth of 70 meters below the sea surface at the deepest, according to the Defense Ministry. But in that section of Oura Bay, soft ground is found at depths of 90 meters at the deepest points.
A private company commissioned by the central government estimated in January that the reinforcement work would take three years and eight months to complete.
That means that the entire work period to relocate the U.S. base will take at least 11 years and eight months.
In light of the necessity to stabilize the soil, the central government in September for the first time assembled technical experts to collect their input on the work.
The experts are expected to come up with a new schedule to complete the reclamation work at a meeting in November.
The central government also aims to present the total project cost by the end of December, a figure that will likely be lower than Okinawa’s projection.
That way, it intends to justify the relocation project before it applies to the prefectural government to alter the plan.
(This article was written by Ryuichi Yamashita and Kazuyuki Ito.)