F or the first time an operating dam in Japan has been slated for removal. Kumamoto governor Yoshiko Shiotani has announced that the Arase hydro dam on the Kumagawa river is to be dismantled in seven years.

Power generation at the dam began in 1954. Generation will continue for another seven years, until 31 March 2010. Kumamoto prefecture will ask the Japanese central government for the possible earliest demolition date after that. The governor cited economic reasons for removing the ageing dam, saying it generates less than 1% of the annual electricity demand in Kumamoto Prefecture and that the cost of keeping it running past 2010 was not economic.

Prefectural officials said about US$50M would be required to replace power generators and dam gates. As the licence for Arase dam will expire next March, Kumamoto Prefecture will ask the Ministry of Land, Infrastructure and Transport for a seven-year extension, instead of the normal 30-year licence. Prefectural officials said it will cost about US$39.2M to demolish the dam.