The is an embankment dam near

Ibigawa is a town located in Ibi District, Gifu Prefecture, Japan. , the town had an estimated population of 21,319 in 8,015 households and a population density of 27 persons per km2, in 8,032 households. The total area of the town was . Geography Ib ...

Ibi District is a district located in Gifu Prefecture, Japan. , the district has an estimated population of 72,109. The total area is 876.65 km2. The area of the former village of Tokuyama in this district will be flooded by the Tokuyama Dam. Towns ...

, Gifu Prefecture in Japan. The dam was completed in 2008 and will support a 153 MW hydroelectric

power station A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid. Many ...

that is expected to be fully operational in 2015. Currently, Unit 1 at 23 MW was commissioned in May 2014. The dam was originally intended to withhold the upper reservoir of a 400 MW

pumped-storage Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential ...

power station until a design change in 2004. The dam is also intended for

flood control Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water level ...

and

water supply Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. Thes ...

. It is the largest dam by structural volume in Japan and withholds the country's largest reservoir by volume as well.

History

In December 1957,

Electric Power Development Company The , operating under the brand name J-POWER, formerly , is an electric utility in Japan. It mainly produces electricity from coal and hydroelectric power stations. It also has a few wind farms and is currently building a nuclear plant in Ohma ...

(J-Power) selected the

Ibi River The is a tributary of the Kiso River located in Gifu and Mie Prefectures in Japan. Along with the Nagara and Kiso rivers, the Ibi is the third of the Kiso Three Rivers of the Nōbi Plain. It is one of Japan's first-class rivers. The former Tō ...

for study at the 23rd Electric Power Development Coordinating Meeting. By May 1976, the Ministry of Construction released their bulletin "Policy on Tokuyama Dam Construction Project". In December 1982, the project was incorporated into the Electric Power Development Basic Plan. It was approved by the government in 1998. The original project was a

pumped-storage hydroelectric Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential ...

scheme which consisted of the Tokuyama Dam as the upper

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

, the Sugihara Dam as the lower and the 400 MW Sugihara Power Plant. The dam is named after the village that once stood there, that was flooded by the construction of the dam. Construction on the dam started in May 2000 but by May 2004 J-Power and Chubu Electric announced they had changed the design of the project due to the concerns and protests of locals and groups. Instead of the pumped-storage hydroelectric scheme, only the Tokuyama Dam would be constructed with a 153 MW conventional power station. Subsequently, the Sugihara Dam and Sugihara Power Plant were scrapped from the project. During construction, the long Tokunoyama Hattoku Bridge was constructed upstream. With improved techniques and equipment, fill for the dam was laid at a pace of per year, enabling the dam to be constructed in 26 months. Sediment from the Yokoyama Dam's reservoir was used as fill as well. In September 2006 initial filling of the reservoir behind the Tokuyama Dam began and by June 2008, the dam was complete. Filling was complete in September. In October of the same year, J-Power passed oversight of the power station construction to Chubu. The first generator, Unit 1, was commissioned on 15 May 2014. Unit 2 should be commissioned by June 2015.

Design

The Tokuyama Dam is a long and high rock-fill embankment dam with a clay core. The total structural volume of the dam is . The dam creates a

with a capacity, surface area of and catchment area of . The dam will support two Francis turbine- generators, one with a 130 MW capacity which will be located in an

underground power station An underground power station is a type of hydroelectric power station constructed by excavating the major components (e.g. machine hall, penstocks, and tailrace) from rock, rather than the more common surface-based construction methods. One or mor ...

downstream. The second is an operational 23 MW generator and is located at the base of the dam. The installed capacity of both will be 153 MW. The power station will process a maximum of for power production.

References

External links

Chubu Electric new projects
{{Dams in Gifu Prefecture Hydroelectric power stations in Japan Rock-filled dams Dams in Gifu Prefecture Dams completed in 2008 Underground power stations 2008 establishments in Japan Ibi District, Gifu