Oct. 20, 2009 (The Yomiuri Shimbun) -- Discord has been growing ever more intense between the central and local governments over the decision to halt the Yamba Dam construction project, which the Democratic Party of Japan-led government cited as the nation's most wasteful public works enterprise.
On Monday, the governors of Tokyo and five prefectures in the Kanto region visited the construction site in Naganoharamachi, Gunma Prefecture, and issued a joint statement denouncing the central government's decision to cancel the project.
"It was very irresponsible to unilaterally announce the cancellation of the construction project and to do so without providing reasons for the cancellation or putting forward an alternative plan [to help compensate local residents adversely affected by the decision]," the governors said in the statement aimed at Construction and Transport Minister Seiji Maehara.
The main points of their argument include whether the dam would have been effective in preventing flooding, and whether demand for water in the Tokyo metropolitan area might outstrip supply without the dam.
Advocates, including local governments and most residents of the dam construction area, argued the dam would negate both threats, while the DPJ argues the dam is unnecessary, saying it is the nation's most wasteful public works project.
On this issue, Maehara has said, "I've addressed the Yamba Dam issue as a theme to be taken up in reviewing river administration," although he has not given specific reasons why he sees it as wasteful.
Maehara has told The Yomiuri Shimbun that he came to his decision based on discussions held by the party's policy research council and other forums.
The arguments advanced during meetings of the panel were written up in an interim report that was issued August 2005 titled "Thoughts on the Yamba Dam Project."
According to the report, the project was planned after Typhoon Kathleen struck in 1947, leaving 1,900 people dead or missing. At that time, the floodwater volume as measured at a reference point at Yattajima, in Isesaki, Gunma Prefecture, on the junction of the Tonegawa and Azumagawa rivers, was 17,000 cubic meters per second.
After taking into account the flow volume at the reference point, the government drew up a plan to build dams at reservoirs along the Tonegawa and rivers that flow into it. Yamba Dam was the only flood-control dam to be built on the Azumagawa under the plan.
In 1980, the government reestimated the peak flow volume at Yattajima at 22,000 cubic meters per second, saying, "River improvement measures likely would increase the flow."
The DPJ says the peak flow figure was overestimated, noting in its interim report that Typhoon Kathleen hit "when the forest was devastated and had low water-retaining capacity," adding that the flow volume would not be so high today.
