A remark commonly heard in Japan in the wake of a natural disaster is, “We couldn’t predict such a thing.” In the case of Typhoon Hagibis, which ravaged the eastern and northern parts of the archipelago in mid-October, the unpredictable thing was the amount of rainfall, which caused massive flooding that resulted in more than 80 deaths and billions of yen in damage. In fact, meteorologists had predicted Hagibis would be the biggest storm to hit eastern Japan in decades and that it would dump an unprecedented amount of water on the region. So when officials say they couldn’t predict the enormity of the typhoon, what they arguably really mean is that they weren’t ready for it.
Nevertheless, some internet commentators have attempted to make the government into a hero. On Oct. 16, online magazine Litera reported a seemingly uncoordinated social media campaign that praised the administration of Prime Minister Shinzo Abe for its foresight in restarting the Yanba Dam project, which is located in the upper reaches of the Tonegawa river in Gunma Prefecture, as well as the “super levees” constructed on portions of the Tamagawa and Arakawa rivers in Tokyo. These measures were touted as having saved lives and homes, but the real purpose of the campaign appeared to be to disparage the now-defunct Democratic Party of Japan, which, during its brief stint as the ruling party from 2009 to 2012, initially tried to cancel both projects because of their cost. The implication is that the DPJ neglected water control while the resurgent Liberal Democratic Party under Abe’s leadership worked resolutely on the matter.
The campaign’s claims were scrutinized by Tokyo Shimbun in an Oct. 17 article. The day before, during an Upper House budget committee meeting, land Minister Kazuyoshi Akaba noted how the dam had prevented water from overwhelming the Tonegawa river.
Tokyo Shimbun says the truth is more complicated. Teruyuki Shimazu, a representative of a citizens group called Japan River Keeper Alliance, argued that had there been no Yanba Dam, the excess runoff in the Tonegawa river would not have raised the water level above existing levees. Relying solely on Yanba Dam to manage water in such a situation is unwise, Shimazu thinks, since collecting runoff for the purpose of flood control has limitations, as shown by actual circumstances with other dams in the affected areas.
As the lawyer for Japan River Keeper Alliance told Tokyo Shimbun, Yanba Dam was in the middle of carrying out tests and had coincidentally lowered the water level in the dam before the typhoon hit. Had the water level started at its normal height, there was a danger the dam would have had to release water during the storm, thus overwhelming the lower reaches of the Tonegawa river. More effective, according to the alliance, would be excavating the middle portion of the Tonegawa river in order to lower the river bed, but land ministry work in that area has so far been “inadequate.”
LDP supporters also credited the super levees for holding back flood waters that might have overwhelmed parts of Tokyo along the Arakawa and Tamagawa rivers, but even the land ministry admitted to Tokyo Shimbun that it couldn’t measure the “effectiveness” of the embankments since only 3.4 kilometers’ worth have been built. The project started in the late 1980s, and the scale has since been reduced from 873 kilometers of levees on six rivers to 120 kilometers on five rivers. So far, only 2.8 percent of that goal has been achieved. At this pace, it will take more than 100 years to complete the levees on the Edo River alone. The original estimates for the entire project was 400 years and more than ¥10 trillion. It’s one of the reasons the DPJ tried to cancel the project but, in any case, they couldn’t bring it to an immediate end. They also rescinded the cancellation of Yanba Dam.
Katsuyoshi Ishizaki, a former deputy manager at the Public Works Research Institute, told Tokyo Shimbun that despite the enormous width of these super levees, they are not impervious to water. Constructed of asphalt, they can erode under certain circumstances. Hirotake Iwamoto, a professor emeritus at Kyoto University, said the best solution would be to reinforce the levees with steel plates, which are cheap and easy to install, but for some reason the land ministry is not interested. Ishizaki theorizes, perhaps cynically, that the ministry, protective of its already enormous budget, is OK with defective levees since resultant damage assures any funding they request in the future.
The Litera article also claims that while the DPJ did reduce the budget for water management, the LDP reduced it even more. Since 1998, the annual budget for water control projects has dropped from ¥3.25 billion to between ¥800 and ¥900 million, despite increased incidence of flooding. The DPJ was in power for around 3½ years during this period.
In a sense, climate change provides an explanation for anyone in authority to fall back on the “it couldn’t be predicted” excuse, and following two devastating typhoons this season the government may be owning up to the futility of trying to second-guess nature. On Oct. 18, the Asahi Shimbun ran two stories that imply the best solution is to discourage people from living in areas at risk of flooding. One describes a Finance Ministry panel recommending revisions of land usage regulations that could necessitate moving entire communities out of harm’s way. In the other, Chiba University professor Tatsuhiro Kamisato admits that Japan is conspicuously prone to disasters because of its geography and geology.
Disasters occur at the nexus of nature and society, Kamisato writes. Earthquakes are scary, but if you’re living in a tent on open land, the quake will not cause much harm. That is why, he says, all so-called natural disasters are really human disasters. Dams and levees are considered effective for taming nature, but in the end they are not only inadequate, but sometimes exacerbate the problem. Last year, five people in western Japan died when water was released from a dam that had reached capacity.
Because of pollution and global warming, we understand that exploiting nature leads to ruin. Fighting it is futile, and maybe just as dangerous.
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