More than a decade has passed since a panel of experts first proposed ways to use the vast green space occupied by the U.S. Marine Corps Air Station Futenma in Okinawa Prefecture once it is returned to Japanese sovereignty.

However, that plan has yet to be fulfilled, nor is it likely to be anytime soon.

The base takes up 476 hectares and is home to 58 aircraft, including trouble-plagued Ospreys. It is situated in the middle of a densely populated residential area of Ginowan city.

It is often called “the world’s most dangerous base” because of the 167 accidents involving Futenma-based aircraft since Okinawa’s return to Japanese sovereignty in 1972. One notable incident was a helicopter crash in the grounds of Okinawa International University in Ginowan in 2004.

In contrast to the packed residential area surrounding the base, the site itself largely remains green, except for the 2,800-meter runway.

Aerial photographs suggest that 70 percent of the area is covered in greenery.

Trees with thick trunks grow in the southeast and northwest, and a forested area has remained untouched since the ferocious Battle of Okinawa raged in 1945.

In 1996, the Japanese and U.S. governments reached an agreement for the land occupied by the U.S. base to be returned to Japan within five to seven years.

However, the relocation plan has been repeatedly postponed, partly due to delays in land reclamation work for an alternative site in the Henoko district in Nago in the prefecture. It now looks likely that the relocation won’t happen before the late 2030s.

The prefectural and city governments drew up an “interim plan” in 2013 on how to utilize the Futenma base’s greenery after the site is returned.

The plan was revised in 2022 to include the creation of a large park on the vacant plot.

“Past plans prioritized use of the land, focusing only on housing development and commercial facilities,” said Takayuki Ikeda, professor emeritus at the University of the Ryukyus who took part in the committee studying the future use of the Futenma site.

“We reversed the order of that priority and chose to utilize Futenma’s greenery, terrain and nature,” he said.

The Naha Shintoshin district, previously a U.S. military housing area, gave a 32-fold jolt to the local economy after it was developed following the return of the site.

This example is often touted as a success. However, it did not fully utilize the site’s obvious appeal, that it faced the ocean. Instead, its sloped terrain was flattened to make way for buildings.

The land, which used to be U.S. military’s Awase Meadows Golf Course, became a giant shopping mall operated by Aeon Co.

In contrast, the centerpiece of the Futenma plan revolves around a large park covering more than 100 hectares.

The vision of a vast green space interspersed with residential areas and research centers embodies a centuries-old Okinawan philosophy, “Bankoku Shinryo,” meaning bridge between nations.

Those involved in the planning say other parks in the southern prefecture were also created with certain ideas in mind.

Ocean Expo Park, built after the 1975 expo, represents subtropical nature, while Shurijo Castle Park reflects the history of the ancient Ryukyu Kingdom that existed until 1879 when it was formally annexed and dissolved by the Meiji government to form Okinawa Prefecture.

Planners want the Futenma park to symbolize peace.

“We want this to be the culmination of (our) postwar resolution,” Ikeda said, referring to hopes, long dashed, that Okinawa would forever remain free of military bases.

It is a poignant sentiment, given that Okinawa hosts about 70 percent of all U.S. military facilities in Japan, an issue that has deeply divided islanders.

The Ginowan city government has also stated it hopes “the site will become a national park.”

PRESERVING GREENERY

The Futenma site sits on terrain that also serves as a natural water reservoir.

Impermeable mudstone lies beneath Ryukyu limestone, which allows groundwater to seep through.

“Futenma’s terrain is like a sponge sitting on a tilted cutting board, which allows water to seep in and flow down,” said Hiroko Ono, a professor of engineering architecture at the University of the Ryukyus, who was a member of the committee studying what to do with the Futenma site.

Multiple groundwater channels cut through a 40-meter-high slope from east to west, creating a cluster of natural springs at the western edge.

The remaining greenery at the Futenma site helps to create groundwater, thereby sustaining the area’s ecosystem.

“If Futenma land is developed, an inevitable outcome will be that the spring water will flow less,” Ono said.

She said it was imperative to preserve green spaces to maintain current water levels.

The plentiful spring water is still used for agricultural purposes and daily life.

In Ginowan’s Oyama district, just west of Futenma, farmers use the spring water to cultivate “taimo,” a type of root vegetable, in fields inundated with water.