The is a

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

on the

Ōi River The is a river in Shizuoka Prefecture, Japan. Geography The Ōi River flows from the Akaishi Mountains, the branch of the Japanese Southern Alps which form the border between Shizuoka, Nagano and Yamanashi prefectures. These mountains, with p ...

in Aoi-ku,

Shizuoka Shizuoka can refer to: * Shizuoka Prefecture, a Japanese prefecture * Shizuoka (city), the capital city of Shizuoka Prefecture * Shizuoka Airport * Shizuoka Domain, the name from 1868 to 1871 for Sunpu Domain, a predecessor of Shizuoka Prefecture ...

Shizuoka Prefecture is a prefecture of Japan located in the Chūbu region of Honshu. Shizuoka Prefecture has a population of 3,637,998 and has a geographic area of . Shizuoka Prefecture borders Kanagawa Prefecture to the east, Yamanashi Prefecture to the northea ...

on the island of

Honshū , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separa ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. A hollow-core

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...

gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it. ...

, it has a

hydroelectric power Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

generating station owned by the

Chubu Electric Power Company , abbreviated as Chuden in Japanese, is a Japanese electric utilities provider for the middle Chūbu region of the Honshu island of Japan. It provides electricity at 60 Hz, though an area of Nagano Prefecture uses 50 Hz. Chubu Electric ...

History

The potential of the Ōi River valley for hydroelectric power development was realized by the

Meiji government The was the government that was formed by politicians of the Satsuma Domain and Chōshū Domain in the 1860s. The Meiji government was the early government of the Empire of Japan. Politicians of the Meiji government were known as the Meiji o ...

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. Design work began in 1902 by the and the first dam on the Ōi River (the Tashiro Dam) was completed in 1927. Further work was suspended by the

Great Depression The Great Depression (19291939) was an economic shock that impacted most countries across the world. It was a period of economic depression that became evident after a major fall in stock prices in the United States. The economic contagio ...

of the 1930s, and

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

in the 1940s. However, by the early 1950s, Japan’s need for electrical energy was growing exponentially. The

Ōigawa Railway Ikawa Line The is a railway line of the Ōigawa Railway. It runs from Senzu Station in Kawanehon, Shizuoka, the end station of the Ōigawa Main Line, and terminates at Ikawa Station in Aoi-ku, Shizuoka. The line has 61 tunnels and 51 bridges along its ...

was expanded to facilitate dam construction, and the newly created Chubu Electric Power Company received a loan from the

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...

Bank for Reconstruction and Development on September 10, 1958 to fund the project. Construction was completed by December 1961, and the system came into operation in early 1962.

Design

The Hatanagi Project was designed as a

Pumped-storage hydroelectricity 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 ...

facility, with the discharge from Hatanagi-I discharging through a five kilometer

penstock A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is inherited from the earlier technology of mill ponds and watermills. H ...

into a lake created by the smaller Hatanagi No.2 Dam downstream. The reversible turbine generators at the Hatanagi No.1 power plant were designed to function as either electrical power generators, or as pumps, to reverse the flow of water back into the reservoir in times of low demand. The generators at the Hatanagi No.1 power plant have a capacity of 137,000 kW, and a maximum flow rate of 137 m³/s. The Hatanagi No.2 power plant adds an additional 85,000 kW to the

electrical grid An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:Kaplan, S. M. (2009). Smart Grid. Electrical Power ...

of the

Tōkai region The is a subregion of the Chūbu region and Kansai region in Japan that runs along the Pacific Ocean. The name comes from the Tōkaidō, one of the Edo Five Routes. Because Tōkai is a sub-region and is not officially classified, there is s ...

of central Japan.

Surroundings

The Hatanagi-II is located in the

Minami Alps National Park is a national park in the Akaishi Mountains, Chūbu region, Honshū, Japan. The Minami Alps National Park was established on June 1, 1964. It extends along the border of Shizuoka, Yamanashi and Nagano Prefectures for a length of , and a ...

, an area of high mountains, forests, and a popular vacation area. Public access to the dam and its lake are by Shizuoka Prefectural Road 60, with bus connections to Ikawa Station or directly with

Shizuoka Station is a major railway station in Shizuoka, Shizuoka Prefecture, Japan, operated by the Central Japan Railway Company (JR Central). Lines Shizuoka Station is served by the Tōkaidō Shinkansen and Tōkaidō Main Line, and is 180.2 rail km from Tok ...

Shin-Shizuoka Station 270px, former station building is a railway station in Aoi-ku, Shizuoka, Shizuoka Prefecture, Japan, operated by the private railway company, Shizuoka Railway (Shizutetsu). It is located within the Shin-Shizuoka Cenova shopping complex. Lines ...

. The dam itself and its associated electrical power plant are not open to the public.

Notes

* Japan Commission on Large Dams. ''Dams in Japan: Past, Present and Future''. CRC Press (2009).

References

Chubu Electric home page

Nations Treaty Organization
{{Dams in Shizuoka Prefecture Gravity dams Dams in Shizuoka Prefecture Hydroelectric power stations in Japan Dams completed in 1961

History

Design

Surroundings

See also

Notes

References