The is a multi-purpose dam on the main stream

Sagami River The is a river in Kanagawa and Yamanashi Prefectures on the island of Honshū, Japan. The upper reaches of the river in Yamanashi prefecture are also sometimes known as the , and the portion near the river mouth as the . The river overall was ...

Sagamihara is a city in Kanagawa Prefecture, Japan. , the city has an estimated population of 723,470, with 334,812 households, and a population density of 1,220 persons per km2. The total area of the city is . Sagamihara is the third-most-populous city ...

Kanagawa Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-densest at . Its geographic area of makes it fifth-smallest. Kana ...

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 ...

, Japan.

History

The potential of the Sagami River valley for

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 a ...

development began to be developed in the 1930s, with the growth of industry and electrical consumption in the

Yokohama is the second-largest city in Japan by population and the most populous municipality of Japan. It is the capital city and the most populous city in Kanagawa Prefecture, with a 2020 population of 3.8 million. It lies on Tokyo Bay, south of ...

Kanagawa is a prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-densest at . Its geographic area of makes it fifth-smallest. Kanagaw ...

industrial belt. Work on the Sagami Dam, the first dam on the main stream of the Sagami River began in 1938; however, lack of funding and the advent of

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 World War II by country, vast majority of the world's countries—including all of the great power ...

delayed completion until after the end of the war. Work on the Shiroyama Dam, in the former town of Tsukui, Tsukui District commenced in 1960 and was completed in 1965 by the

Kumagai Gumi is a Japanese construction company founded in Fukui, Fukui Prefecture, Japan. The company still has registered headquarters in Fukui, but the actual head office is located in Shinjuku, Tokyo. History Santaro Kumagai, the company's founder, be ...

construction company.

Design

The Shiroyama Dam is 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 ...

gravity dam. It was designed to provide

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 industrial and drinking water to the cities of Yokohama, Kawasaki,

Yokosuka is a city in Kanagawa Prefecture, Japan. , the city has a population of 409,478, and a population density of . The total area is . Yokosuka is the 11th most populous city in the Greater Tokyo Area, and the 12th in the Kantō region. The ...

and the

Shōnan is the name of a region along the coast of Sagami Bay in Kanagawa Prefecture, central Japan. Centered on Sagami River, about 60 kilometers southwest of Tokyo, the Shōnan region stretches from Ninomiya in the west to Fujisawa in the east, ...

area. It also serves 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 potent ...

facility in conjunction with the

Honzawa Dam is a dam in Midori-ku, Sagamihara, Kanagawa Prefecture, 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 ...

further upstream. The associated Shiroyama Hydroelectric Power Plant has a rated capacity of 250,000 kW of power, and the Tsukui Hydroelectric Power Plant has an additional capacity of 25,000 kW. The reversible turbine generators at the Shiroyama Power Plant were designed to function as either electrical power generators, or as pumps, to reverse the flow of water back into the reservoir of the Honzawa Dam in times of low demand. created by the dam is a major leisure destination in Kanagawa Prefecture, popular with boaters, fishers and campers.

Surroundings

Public access to the Shiroyama Dam and to Lake Tsukui are by

Japan National Route 413 National Route 413 is a national highway of Japan connecting Fujiyoshida, Yamanashi and Sagamihara, Kanagawa in Japan, with a total length of 71.7 km (44.55 mi). The road goes through Dōshi is a village located in Yamanashi Pr ...

, which actually runs across the top of the dam itself. Tsukuiko Shiroyama park is located near the dam.

References

*Japan Commission on Large Dams. ''Dams in Japan:Past, Present and Future''. CRC Press (2009). *Takeuchi, Kuniyoshi. ''Sustainable Reservoir Development and Management''. IAHS Press (November 1998).

External links

photo page
{{Authority control Gravity dams Dams in Kanagawa Prefecture Hydroelectric power stations in Japan Dams completed in 1965 1965 establishments in Japan