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 ...

on the

Kitakami River The is the fourth largest river in Japan and the largest in the Tōhoku region. It is long and drains an area of . page 793 It flows through mostly rural areas of Iwate and Miyagi Prefectures. The source of the river is the Mount Nanashirug ...

, located in

Morioka is the capital city of Iwate Prefecture located in the Tōhoku region of northern Japan. On 1 February 2021, the city had an estimated population of 290,700 in 132,719 households, and a population density of . The total area of the city is . ...

Iwate Prefecture is a prefecture of Japan located in the Tōhoku region of Honshu. It is the second-largest Japanese prefecture at , with a population of 1,210,534 (as of October 1, 2020). Iwate Prefecture borders Aomori Prefecture to the north, Akita Prefectur ...

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 ...

History

Shijūshida Dam is the fourth in a series of five multipurpose dams built directly on the main stream of the Kitakami River, starting with the

Tase Dam is a multipurpose dam located on the Sarugaishi River in the former town of Tōwa which is now a part of the city of Hanamaki in Iwate Prefecture, in the Tohoku region of northern Japan. Completed in 1954, it is managed by the Tohoku Regio ...

in 1941. The project was launched by the Economic Stabilization Bureau in 1947 following Typhoon Kathleen in September 1947 (which killed 1547 people). The need for a dam primarily 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 ...

was emphasized by Typhoon Ione in September of the following year, which killed an additional 1956 people. The dam was first completed by the

Kajima Corporation is one of the oldest and largest construction companies in Japan. Founded in 1840, the company has its headquarters in Motoakasaka, Minato, Tokyo. The company is known for its DIB-200 proposal. The company stock is traded on four leading Jap ...

in 1968.

Design

The Shijūshida Dam was designed as a concrete gravity arch dam; however, since the rocks on both banks were weak, the dam was completed as a hybrid design with earthen dams on the sides and a concrete gravity dam in the center. The project was complicated by the extreme acidity of the water (reaching pH of 4.0) due to runoff from the

Matsuo mine , was an iron and sulphur mine located in the village of Matsuo, Iwate Prefecture in the Tohoku region of northern Japan. The area is now part of the city of Hachimantai. The mine opened in 1914 and closed in 1979 leaving a ghost town behind. H ...

upstream. This acidity resulted in the use of special concrete and alloy materials. Generators for the associated

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 ...

plant product 15,100 KW of electricity.

References

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