Tashiro Dam

The Tashiro Dam (田代ダム, Tashiro damu) is a dam on the Ōi River in Aoi-ku, Shizuoka, Shizuoka Prefecture on the island of Honshū, Japan. It was the first concrete gravity dam to be constructed on the Ōi River, and has a hydroelectric power generating station owned by the Tokyo Electric Power Company. The potential of the Ōi River valley for hydroelectric power development was realized by the Meiji government at the start of the 20th century. The Ōi River was characterized by a high volume of flow and a fast current. Its mountainous upper reaches and tributaries were areas of steep valleys and abundant rainfall, and were sparsely populated. In 1906, a joint venture company, the Anglo-Japanese Hydroelectric Company (日英水力電気, Nichiei Suiroku Denki) was established, and began studies and design work on plans to exploit the potential of the Ōi River and Fuji River in Shizuoka Prefecture. The British interests were bought out by 1921, and the company was renamed Hayakawa Electric (早川電力, Hayakawa Denryoku), for its plan to divert water from the Ōi River to the Hayakawa River in Yamanashi Prefecture through a system of penstocks, and thus generate electricity. Work on the Tashiro Dam began in 1924 and was completed in 1928. Hayakawa Electric was absorbed into Tokyo Electric (東京電燈, Tokyo Dento), which was later nationalized and merged with other electrical producers into the Japan Electric Generation and Transmission Company (日本発送電株式会社, Nippon Hassoden K.K.). After the breakup of Nippon Hassoden at the end of World War II into various regional power utilities, the bulk of the dams on the Ōi River came under the control of Chubu Electric Power.