KAMAISHI, Japan » After three decades and nearly $1.6 billion, work on Kamaishi’s great tsunami breakwater was completed three years ago. A mile long, 207 feet deep and jutting nearly 20 feet above the water, the quake-resistant structure made it into the Guinness World Records last year and rekindled fading hopes of revival in this rusting former steel town.

But when a giant tsunami hit Japan’s northeast on March 11, the breakwater largely crumpled under the first 30-foot-high wave, leaving Kamaishi defenseless. Waves deflected from the breakwater are also strongly suspected of having contributed to the 60-foot waves that engulfed communities north of it.

Its performance that day, coupled with its past failure to spur the growth of new businesses, suggested that the breakwater would be written off as yet another of the white elephant construction projects littering rural Japan. But Tokyo quickly and quietly decided to rebuild it as part of the reconstruction of the tsunami-ravaged zone, at a cost of at least $650 million.

After the tsunami and the nuclear meltdowns at Fukushima, some Japanese leaders vowed that the disasters would give birth to a new Japan, the way the end of World War II had done. A creative reconstruction of the northeast, where Japan would showcase its leadership in dealing with a rapidly aging and shrinking society, was supposed to lead the way.

But as details of the government’s reconstruction spending emerge, signs are growing that Japan has yet to move beyond a postwar model that enriched the country but ultimately left it stagnant for the past two decades.

As the story of Kamaishi’s breakwater suggests, the kind of cozy ties between government and industry that contributed to the Fukushima nuclear disaster are driving much of the reconstruction and the fight for a share of the $120 billion budget expected to be approved in a few weeks.

The insistence on rebuilding breakwaters and sea walls reflects a recovery plan out of step with the times, critics say, a waste of money that aims to protect an area of rapidly declining population with technology that is a proven failure.

Defenders say that if Kamaishi’s breakwater is not fixed, people and businesses will move away even faster for fear of another tsunami.

"There may be an argument against building a breakwater in a place with little potential to grow, but we’re not building a new one — we’re basically repairing it," said Akihiro Murakami, 57, the top official in Kamaishi for the Ministry of Land, Infrastructure, Transport and Tourism, which oversees the nation’s breakwaters. "At this point, it’s the most efficient and cost-effective choice."

After World War II, Japan built a line of coastal defenses that were longer than China’s Great Wall and ultimately stretched to a third of the Japanese coastline. The defenses allowed more Japanese, whose numbers rose to 125 million from 72 million in the five decades after 1945, to live and work hard by the sea.

Yet, even before the tsunami, the affected zone’s population was expected to age and shrink even faster than the rest of Japan’s, contracting by nearly half over the next three decades. Critics say that in cities like Kamaishi, where the population dropped from 100,000 people four decades ago to fewer than 40,000 before the tsunami, people should simply be moved away from the ravaged coast.

Japan’s dwindling resources would be better spent merging destroyed communities into inland "compact towns" offering centralized services, critics say. Unnecessary public works — Kamaishi’s reconstruction plans include building a rugby stadium — would merely hasten the tsunami zone’s decline by saddling it with high maintenance costs.

"In 30 years," said Naoki Hayashi, a researcher at the Central Research Institute of Electric Power Industry, one of Japan’s biggest policy groups, "there might be nothing left there but fancy breakwaters and empty houses."

A WEB OF COLLUSION

Even though the breakwater yielded economic benefits only to the vested interests that have a grip on the construction of Japan’s breakwaters, sea walls and ports, advocates of its reconstruction say it is vital to Kamaishi’s future. In addition to protecting the city against tsunamis, the breakwater was intended to create a modern international port that would accommodate container vessels and draw new companies here.

The birthplace of Japan’s modern steel industry, Kamaishi lived through economic booms for nearly a century, but by the early 1970s its major employer, Nippon Steel, was moving steel production to central Japan, where the flourishing auto industry was concentrated.

Construction, which began in 1978, was completed three years ago.

"It was good for the ministry," said Yoshiaki Kawata, a member of the government’s reconstruction design council, referring to the Land Ministry. "But the city declined. Businesses and people left."

It was good not only for the ministry, but also for its allies in politics and business, who joined forces in the kind of collusive web that is replicated in many other industries.

For decades, Zenko Suzuki, a former prime minister who died in 2004, secured the money for this region’s breakwaters, sea walls and ports. He was supported by local businessmen like Kazunori Yamamoto, 65, the owner of Kamaishi’s biggest construction company, which helped build the breakwater.

Yamamoto once led a youth group that backed the politician, with whom he fondly remembered attending golf tournaments. "He took great care of me," he said.

A career bureaucrat named Teruji Matsumoto headed the ministry division overseeing the breakwater’s construction in the early 1980s. In 1986, he joined Toa Construction, one of the three big marine construction companies that managed the breakwater’s construction, rising to chief executive in 1989.

Isao Kaneko, a high-ranking manager at Toa, said of Matsumoto, "Maybe someone looking from the outside would view it as collusion, but he was an absolutely indispensable person for our company."

Reached by telephone, Matsumoto, now 84, declined to be interviewed, saying he was suffering from "depression" and "senility."

COLLAPSE AFTER FIRST WAVE

Despite the breakwater’s failure to halt Kamaishi’s decline, its defenders contended that it was steadfastly protecting the city from tsunamis by sealing off the bay from the Pacific, except for a small opening for boats. The Land Ministry extolled its breakwater in a song, "Protecting Us for a Hundred Years."

"It protects the steel town of Kamaishi, it protects our livelihoods, it protects the people’s future," the song goes.

On March 11, the tsunami’s first wave reached Kamaishi 35 minutes after the earthquake struck off the northeast coast at 2:46 p.m. In a video shot from the third floor of a Land Ministry building facing the port, 48 people who have taken shelter can be heard in the background as they watch the breakwater’s collapse against the first wave.

"The breakwater is failing completely," one man says softly as the waves spill over the breakwater, turning its inner wall into a white, foamy waterfall. Minutes later, the tsunami roars into Kamaishi, sweeping away nearly everything in its way.

The breakwater becomes visible seven minutes later as the first wave starts ebbing out of the city. "Wow, look at the shape of the breakwater!" an astonished man says. "It’s collapsed." The camera zooms in on the breakwater, as the top of it lies twisted in fragments. As the people brace themselves for the tsunami’s second wave, an exasperated man says, "This breakwater isn’t working at all."

Those in the building survived, but 935 Kamaishi residents died in the tsunami.

"I was disappointed," said Yoshinari Gokita, an executive at Toa Construction who spent 10 years here working on the breakwater. "We all did our best. We used to say proudly that as long as it was there, everyone would be absolutely safe."

Kamaishi is a hilly city with little flat land. Rising directly behind its port and central district, steep hills have long provided a natural tsunami shelter that was equipped with an elaborate network of evacuation stairways, pathways and resting areas after World War II. Most inside the tsunami-prone central district were within only a couple of hundred yards of the nearest evacuation stairway, reinforcing the belief that, despite the 35 minutes between the earthquake and the arrival of the first wave, many victims chose not to flee, believing they were safe.

Takenori Noda, Kamaishi’s mayor, said loudspeakers all over the city had warned people to flee. "But I do believe that, unconsciously, the breakwater’s presence did give people a false sense of security," he said.

CONFLICTING RESEARCH

Within days, however, the Land Ministry commissioned an assessment of the breakwater’s performance.

Drawing on the only tsunami data available, captured by a GPS tracking system set up 12 miles offshore, researchers used computer modeling to conclude that the breakwater had done its job: It had reduced the height of the first wave by 40 percent, delayed its landing by six minutes and saved countless lives.

The report, released less than three weeks after the tsunami, would prove decisive. It quickly became accepted wisdom in Kamaishi. It also supplied supporters of the breakwater’s reconstruction with their main argument.

The report was put together by a semi-governmental agency, the Port and Airport Research Institute, which until 2001 had been part of the Land Ministry and now lies under its jurisdiction. Its ranks are staffed by people who served in the Land Ministry during the breakwater’s construction and joined the institute in a widely criticized practice called "amakudari," or "descent from heaven." Officials at the ministry and the institute acknowledged the close ties, but said the report’s findings were neutral.

Seisuke Fujisawa, a part owner of a cement company that benefited from the breakwater’s construction, disagreed. "There is no way that an organization with such close ties to the ministry will say that the breakwater was a failure and a monumental waste of money," he said. "We need a neutral investigation."

"I thought Kamaishi was safe because of the breakwater," said Fujisawa, 66, whose family has operated various businesses in Kamaishi for seven generations. "But now I don’t believe the breakwater was effective at all."

Recently, researchers came to a similar conclusion. According to computer modeling by researchers at the Japan Agency for Marine-Earth Science and Technology, a semi-governmental organization with no ties to the Land Ministry, the breakwater had no significant effect in decreasing the size of the first wave or delaying its arrival.

Mizuho Ishida, the lead researcher and a former president of the Seismological Society of Japan, said differences in interpretation were inevitable because estimates had to be extrapolated from the wave data collected 12 miles offshore.

"Even if you perform a very fine analysis, there is no way to know exactly what happened," Ishida said.

With Finance Ministry officials also asking hard questions about the cost of rebuilding, the pro-reconstruction forces pushed back in the spring, led by Fukuichi Hiramatsu, a city councilman of 40 years whose family business — gravel — was a subcontractor during the breakwater’s construction.

In an interview in May, Hiramatsu, who died in July at the age of 80, said the city council passed a resolution calling for the breakwater’s reconstruction the day after he had urged the council chairman to do so in a telephone conversation — an episode confirmed by other council members.

What is more, after the mayor publicly expressed doubts about the breakwater’s performance, Hiramatsu said he told him, "‘Instead of saying that it was barely effective, you should mention how effective it was."’

Mayor Noda denied that Hiramatsu, who happened to be a relative by marriage, had influenced him. But the mayor soon sided with Hiramatsu, even signing a separate resolution urging the breakwater’s rapid reconstruction.

Land Ministry officials in Tokyo now proclaimed that the people of Kamaishi were the ones demanding the breakwater’s reconstruction.

"Whether the breakwater was a little effective or delayed the first wave by a few minutes — it’s irrelevant," said Kosuke Motani, a senior vice president at the Development Bank of Japan and a member of the government’s Reconstruction Design Council. "That’s complete nonsense. People should just flee.

"What’s inexcusable is taking advantage of the current confusion to rebuild this breakwater because they don’t want to admit that it was meaningless in the first place," Motani said.

RISK OF AMPLIFYING WAVES

In their push to rebuild, bureaucrats brushed aside the possibility that the breakwater had amplified the destruction of at least two communities.

During the breakwater’s design phase, bureaucrats commissioned coastal engineers at Tohoku University to weigh the risk that the breakwater would deflect tsunami waves from central Kamaishi to the north. After experiments over four years, researchers concluded in reports submitted in 1974 and 1975 that the breakwater would increase the waves directed toward Ryoishi, a district behind a narrow bay just north of Kamaishi Bay, and Kariyado, a fishing village on a peninsula sticking out east of it. A 1976 report states that the waves reaching Ryoishi would increase by 20 percent.

"Building a breakwater at Ryoishi became a prerequisite for building the breakwater at Kamaishi," said Akira Mano, who assisted in the experiments at the time as a graduate student and now teaches at the university.

Ryoishi, which had no coastal defenses until then, was shielded with a breakwater in its bay and a 30-foot-high sea wall along its coast.

On March 11, 60-foot-high waves — twice the height of those seen in central Kamaishi — annihilated Ryoishi and Kariyado. Standing at an evacuation spot high above Ryoishi, Hajime Seto, 66, a retired banker who is the Ryoishi district leader, filmed the destruction while using a bullhorn to warn people to seek higher ground. The tsunami killed 45 people out of the district’s population of 600, but swept away all but 15 of 230 houses.

"They claim that Kamaishi’s breakwater had no effect on us, but we want at least a proper investigation," Seto said. "They want to rebuild the breakwater at all cost, but, under present conditions, we’re opposed to it."

Meanwhile, waves overwhelmed the breakwater in front of Kariyado and reached the middle of a hill where the house of Kozo Sasaki, 80, and his wife, Mitsuko, 68, stood.

The Sasakis, who were recently cleaning out their home before its scheduled demolition, believed that the Kamaishi breakwater increased the waves that destroyed their home.

"It was a plus for them over there, but over here — well, everyone here believes that because the waves were suppressed over there, they came here," Mitsuko Sasaki said.

Shigeo Takahashi, the president of the Port and Airport Research Institute, which assessed the breakwater’s performance for the Land Ministry, said he did not believe that the breakwater had significantly increased the waves at Ryoishi or Kariyado. But pressed, Takahashi acknowledged that his institute had performed only a "rough" analysis of the breakwater’s effect on those communities. He added that his institute had no plans to open a full-fledged investigation.

Kawata, the member of the government’s Reconstruction Design Council, said an investigation’s findings could lead to lawsuits or at the very least impede the breakwater’s reconstruction.

"For them," he said of ministry officials, "there’s just no benefit in conducting an investigation, even though some residents may be asking for one."

Murakami, the Land Ministry official, said he was unaware of the experiments conducted by Tohoku University in the mid-1970s.

"To be honest, whenever we undertake a big project like this, we get all sorts of irrelevant complaints, baseless accusations," he said. He had already reassured residents that the breakwater did not heighten the waves that destroyed their communities.

"I told them that our breakwater wasn’t that big a deal."