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, aqua ...

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 ...

in Haibara District, Kawanehon,

Shizuoka Prefecture is a Prefectures of Japan, prefecture of Japan located in the Chūbu region of Honshu. Shizuoka Prefecture has a population of 3,555,818 and has a geographic area of . Shizuoka Prefecture borders Kanagawa Prefecture to the east, Yamanashi Pref ...

on the

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

Honshū , historically known as , is the largest of the four main islands of Japan. It lies between the Pacific Ocean (east) and the Sea of Japan (west). It is the seventh-largest island in the world, and the second-most populous after the Indonesian ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. It has a

hydroelectric power Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

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 ...

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 A joint venture (JV) is a business entity created by two or more parties, generally characterized by shared ownership, shared returns and risks, and shared governance. Companies typically pursue joint ventures for one of four reasons: to acce ...

company, the was established, and began studies and design work on plans to exploit the potential of the Ōi River and

Fuji River The is a river in Yamanashi Prefecture, Yamanashi and Shizuoka Prefectures of central Japan. It is long and has a drainage basin, watershed of . With the Mogami River and the Kuma River (Japan), Kuma River, it is regarded as one of the three mos ...

in Shizuoka Prefecture. The British interests were bought out by 1921. The Ōigawa Dam was the second dam to be constructed on the main stream of the Ōi River. Construction began in 1934 and was completed in 1936. Electrical production was nationalized under the aegis of the in 1938, which was divided after

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

into regional power corporations. The Oikawa Dam is now operated and maintained by the

Design

Construction of the Ōigawa Dam was facilitated by its location on 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 Railway Ōigawa Main Line, Ōigawa Main Line, and terminates at Ikawa Station in Aoi-ku, Shizuoka. The line has 61 t ...

, which was built largely to more materials and works up the Ōi River valley for dam construction. The design is a solid-core

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

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. Gravity dams are designed so that each section of the dam is ...

. The associated Ōigawa Hydroelectric Power Plant produces 68,200 KW of power.

Surroundings

Public access to the dam and its lake are by Shizuoka Prefectural Road 60, with bus connections to

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

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 ...

References

*Japan Commission on Large Dams. ''Dams in Japan:Past, Present and Future''. CRC Press (2009).
Photo site
{{DEFAULTSORT:Oigawa Dam Gravity dams Dams in Shizuoka Prefecture Hydroelectric power stations in Japan Dams completed in 1936