Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives. It was referred to as Hoover Dam after President Herbert Hoover in bills passed by Congress during its construction, but was named Boulder Dam by the Roosevelt administration. The Hoover Dam name was restored by Congress in 1947.
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, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC.
The Three Gorges Dam is a hydroelectric gravity dam that spans the Yangtze River by the town of Sandouping, in Yiling District, Yichang, Hubei province, central China, downstream of the Three Gorges. The Three Gorges Dam has been the world's largest power station in terms of installed capacity (22,500 MW) since 2012. The dam generates an average 95±20 TWh of electricity per year, depending on annual amount of precipitation in the river basin. After the extensive monsoon rainfalls of 2020, the dam's annual production nearly reached 112 TWh, breaking the previous world record of ~103 TWh set by Itaipu Dam in 2016.
A spillway is a structure used to provide the controlled release of water from a dam or levee downstream, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure that water does not damage parts of the structure not designed to convey water.
The Mangla Dam is a multipurpose dam situated on the Jhelum River in the Mirpur District of Azad Jammu and Kashmir, Pakistan. It is the sixth-largest dam in the world. The village of Mangla, which sits at the mouth of the dam, serves as its namesake. In November 1961, the project's selected contractors were revealed; it was announced that Binnie & Partners, a British engineering firm, was going to serve as the lead designers, engineers, and inspectors for the construction of the dam. The project was undertaken by a consortium known as the Mangla Dam Contractors, which consisted of eight American construction firms sponsored by the Guy F. Atkinson Company based in South San Francisco, California.
The Shinano River, known as the Chikuma River in its upper reaches, is the longest and widest river in Japan and the third largest by basin area. It is located in northeastern Honshu, rising in the Japanese Alps and flowing generally northeast through Nagano and Niigata Prefectures before emptying into the Sea of Japan.
The Kuma River is a river in Kumamoto Prefecture, central Western part of Kyūshū, Japan. It is sometimes referred as Kumagawa River. It is the longest river in Kyushu, with the length of 115 km long and has a drainage area of 1,880 km2 (730 sq mi). The tidal flat of the Kuma River estuary is approximately 1000 hectares.
Malampuzha Dam is the second largest dam and reservoirs in Kerala, located near Palakkad, in the state of Kerala in South India, built post independence by the then Madras state. Situated in the scenic hills of the Western Ghats in the background it is a combination of a masonry dam with a length of 1,849 metres and an earthen dam with a length of 220 metres making it the longest dam in the state. The dam is 355 feet high and crosses the Malampuzha River, a tributary of Bharathappuzha, Kerala's second longest river. There is a network of two canal systems that serve the dam's reservoir of 42,090 hectares.
The La Mesa Dam and Reservoir is an earth dam in Quezon City, Philippines. Its reservoir can hold up to 50.5 million cubic meters, occupying an area of 27 square kilometers (10 sq mi). It is part of the Angat-Ipo-La Mesa water system, which supplies most of the water supply of Metro Manila.
The Shō River has its source in Mount Eboshi in the Shōkawa-chō area of Takayama, Gifu Prefecture, Japan. After flowing for 115 km (71 mi) through the northern part of Gifu Prefecture and the western part of Toyama Prefecture, it empties into Toyama Bay.
The Samanala Dam is a dam primarily used for hydroelectric power generation in Sri Lanka. Commissioned in 1992, the Samanalawewa Project is the third-largest hydroelectric scheme in the country, producing 405 GWh of energy annually. It was built with financial support from Japan and the United Kingdom. It is notable for a large leak on its right bank. Power production continues as planned despite the leakage, and the water from the leak now provides two thirds of the water issued by the reservoir for agriculture in downstream areas.
The Upper Kotmale Dam is located in Talawakele, within the Nuwara Eliya District, in the Central Province of Sri Lanka. The dam feeds the third largest hydroelectric power station in the country.
Ōhashi Dam (大橋ダム) is a dam built on the Yoshino River in Agawa District, Kōchi Prefecture of Japan. This concrete dam 73.5m high. It is a hydroelectric dam of the Shikoku Electric Power Company. It supplies water to the company's hydroelectric plant, Ōhashi Power Station, which can produce up to 5,500kW. It is the lower reservoir for a pumped-storage hydroelectric plant. The upper reservoir being Inamura Dam. Water flowing between these two can produce up to 615MW. It is a public works which The Japan Society of Civil Engineers has recommended as a site of Public Works Heritage.
Water supply and sanitation in Japan is characterized by numerous achievements and some challenges. The country has achieved universal access to water supply and sanitation; has one of the lowest levels of water distribution losses in the world; regularly exceeds its own strict standards for the quality of drinking water and treated waste water; uses an effective national system of performance benchmarking for water and sanitation utilities; makes extensive use of both advanced and appropriate technologies such as the jōkasō on-site sanitation system; and has pioneered the payment for ecosystem services before the term was even coined internationally. Some of the challenges are a decreasing population, declining investment, fiscal constraints, ageing facilities, an ageing workforce, a fragmentation of service provision among thousands of municipal utilities, and the vulnerability of parts of the country to droughts that are expected to become more frequent due to climate change.
Bisalpur Dam is a gravity dam on the Banas River near DEOLI in Tonk district, Rajasthan, India. The dam was completed in 1999 for the purpose of irrigation and water supply.
The Shin-Takasegawa Pumped Storage Station (新高瀬川発電所) uses the Takase River to operate a pumped storage hydroelectric scheme about 12 kilometres (7.5 mi) west of Ōmachi in Nagano Prefecture, Japan. Part of the system is within Chūbu-Sangaku National Park.
The Kukule Ganga Dam is a 110 m (360 ft) gravity dam built across the Kukule River in Kalawana, Sri Lanka. The run-of-river-type dam feeds an underground hydroelectric power station located approximately 5 kilometres (3.1 mi) away, via tunnel.
The Shimokotori Dam is a rock-fill dam on the Shimokotori River about 15 km (9.3 mi) west of Hida in Gifu Prefecture, Japan. The primary purpose of the dam is hydroelectric power generation and water from its reservoir is diverted via a 8.5 km (5.3 mi) long headrace tunnel to a 142 MW power station northeast of the dam. The power station discharges the water into the Jinzū River. Construction on the dam began in 1970 and it was completed in 1973. The power station went operational in May 1973 and is owned by Kansai Electric Power Company.
A volcanic crater lake is a lake in a crater that was formed from explosive activity or collapse during a volcanic eruption.
