Editorial: Gov’t irresponsible to start Okinawa base land reclamation despite soft soil

The Japanese government has commenced full-scale land reclamation work in Oura Bay off the Henoko district of Nago, Okinawa Prefecture, in preparation for the relocation of U.S. Marine Corps Air Station Futenma from the prefectural city of Ginowan to the area.

The seafloor in the area hosts a vast swath of soft ground, described as “mayonnaiselike.” For this reason, the government will drive more than 70,000 piles into the soil to a depth of some 70 meters from the ocean surface to improve the ground.

The government explains that “there is an extremely hard clay layer” below a depth of 70 meters, but some experts have pointed out that the soft ground goes as deep as 90 meters or so. Even though the Okinawa Prefectural Government has called for an additional survey, the central government has not complied with the request.

To begin with, under current technology it is only possible to drive piles to a depth of roughly 70 meters from a barge, making the landfill work underway unprecedentedly difficult for Japan.

We would have to say it is irresponsible for the government to forcibly carry out such difficult construction work with technical questions left unanswered.

Due to the discovery of the weak soil, the construction schedule has been significantly pushed back and the total cost of construction has snowballed. Initially, the government had put the cost at over 350 billion yen (approx. $2.4 billion), but the need for soil improvement work has driven up the cost by some 2.7 times to approx. 930 billion yen (about $6.4 billion). The project had already cost some 400 billion yen (approx. $2.8 billion) as of fiscal 2022.

The land reclamation work has just started. Concerns that the cost may further balloon remain due in part to soaring labor and material costs. Based on case examples of landfill work elsewhere and other factors, the Okinawa Prefectural Government has released its own estimate that the reclamation work off Henoko will ultimately cost 2.55 trillion yen (approx. $17.66 billion).

The commencement of full-scale reclamation work may further deepen the rift between the national and Okinawa governments. Okinawa Gov. Denny Tamaki criticized the central government’s move, saying, “It’s extremely regrettable that they have commenced the work unilaterally.”

While Tamaki has refused to approve a design change for soil improvement work, the central government resorted to “execution by proxy” at the end of 2023 to green-light the alteration on behalf of the prefectural government. While execution by proxy is stipulated in the Local Autonomy Act, the national government’s heavy-handed move to deprive a local body of its authority sparked criticism.

The Okinawa government has pointed to the risks of significant ground subsidence after the landfill work is completed. If that’s the case, it will disrupt the operation of the new base. A deadlock in the Futenma air base relocation plan would end up leaving the base where it is now as “the world’s most dangerous air station” in the heart of an urban area.

For so many years, Okinawa Prefecture has been forced by the national government to bear the excessive burden of hosting a number of military bases. It is not acceptable for the central government to push through construction work with high uncertainty while having no dialogue with the local community, thereby continuing to force Okinawa residents to shoulder a “negative legacy.”