The is a multi-purpose

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 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 Prefectures of Japan, prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the List of Japanese prefectures by population, second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-dens ...

on the island of

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 ...

History

The potential of the Sagami River valley for

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 ...

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

Yokohama is the List of cities in Japan, second-largest city in Japan by population as well as by area, and the country's most populous Municipalities of Japan, municipality. It is the capital and most populous city in Kanagawa Prefecture, with a popu ...

Kanagawa is a Prefectures of Japan, prefecture of Japan located in the Kantō region of Honshu. Kanagawa Prefecture is the List of Japanese prefectures by population, second-most populous prefecture of Japan at 9,221,129 (1 April 2022) and third-dens ...

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 (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 ...

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 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 ...

. It was designed to provide

flood control Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and ru ...

, 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 373,797, 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 city i ...

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 Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and ...

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 (electrical power), load balancing. A PSH system stores energy i ...

facility in conjunction with the Honzawa Dam 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, 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