What is Dam ?

Storage dams may also provide a water supply, or improved habitat for fish and wildlife. They may store water for hydroelectric power generation, irrigation or for a flood control project

should be possible without involving significant uprooting of population, loss of cultivable land due to submergence or loss of existing construction. Also, strategically the location of a dam, especially a major project, is so decided as to cause minimum damage to the public in case of its destruction or failure.

Storage dams are the most common type of dams and in general the dam means a storage dam unless qualified otherwise.

Located in southwest Tasmania in Australia, Gordon Dam is a double curvature concrete arch dam. One of the dam's amazing feature is that it's curved both in the vertical and horizontal directions to resist large hydraulic pressures coming from the 12,359,040 megaliters of water in Lake Gordon, the largest lake in Australia. The immense volume of water is diverted 183 m to the underground power station, where three hydro turbines can generate up to 432 MW of power. Approximately 13% of Tasmania's electricity demand is provided by the Gordon Power Station.

Technically, the site should be as sound as possible – strong, impermeable and stable. Strong rocks at the site make the job of the designer much easy – he can evolve best deigns. Impermeable sites ensure better storage inventories.

A diversion dam is constructed for the purpose of diverting water of the river into an off-taking canal (or a conduit).

Out of the 48 arch dams that have been built in Australia, Gordon Dam is one of the only nine that is designed to be a double curving dam.

ability with reference to seismic shocks and slope failures around the dam, especially upstream, are a great relief to the public in general and the engineer in particular. The slips, slides, and slope failures around and under the dam and susceptibility to shocks during an earthquake could prove highly hazardous.

They provide sufficient pressure for pushing water into ditches, canals, or other conveyance systems

Contra Dam is a slender concrete arch dam standing at a height of 220 m with a crest length of 380 m. Because of the dam's slender design, the volume of concrete required to construct it was reduced and consequently cutting down the cost of the infrastructure.

This 93 m concrete arch dam in California, USA is one of the coolest dams in the world because of its mesmerizing spillway called the Glory Hole. The spillway is an uncontrolled morning glory type with a tip diameter of 22 m and sits within the perimeters of Lake Berryessa, the seventh largest man-made lake in California. It can drain 48,400 cubic feet per second of water during the lake's peak level that occurs when the lake rises to 4.7 m above the spillway's lip. The exit end of the spillway is also famous as a full pipe for skateboarders.

Constructionally, the site should not be far off from deposits of materials which would be required for its construction. All types of major dams require millions of cubic meters of natural materials—earth, sand, gravel and rock – for their construction. Their non-availability in the adjoining areas would make the project cost too high, may be even unfeasible.

A diversion dam is usually of low height and has a small storage reservoir on its upstream. The diversion dam is a sort of storage weir which also diverts water and has a small storage. Sometimes, the terms weirs and diversion dams are used synonymously.

Monticello dam impounds the Putah Creek that can generate 56,806,000 kWh of power annually using 2x5 MW and 1x1.5 MW turbines.

Economically, the benefits arising out of a dam placed at a particular site should be realistic and justified in terms of land irrigated or power generated or floods averted or water stored. Dams are invariably costly structures and cannot be placed anywhere and everywhere without proper analysis of cost-benefit aspects.

Detention dams are constructed for flood control. A detention dam retards the flow in the river on its downstream during floods by storing some flood water

The fish culture in the stream is the first sector to suffer a major shock due to construction of a dam. Its destruction may cause indirect effects on the population. These effects require as thorough analysis as for other objects. The dam and the associated reservoir should become an acceptable element of the ecological set up of the area.

Hoover Dam is one of the most iconic dams around the world stretching between the American states of Nevada and Arizona. Originally called the Boulder dam, this colossal structure stands at a height of 221.4 m, with a base width of 200 m and a crest width of 14 m. It's a concrete gravity-arch dam that was constructed with the purpose to control flood, provide irrigation water, produce hydroelectric power, store water, and for recreation. The hydropower station houses various types of turbines like a 1x61.5 MW Francis turbine and 2x2.4 MW Pelton turbine, which produce an annual electrical output of 4.2 TWh.

A dam is a barrier designed and constructed to contain the flow of water. It is often built in conjunction with a hydroelectric power station to provide electricity.

About 50,000 dams with a height of 15 meters or more and millions of smaller dams have been built on the world’s rivers. Some of them date back centuries, but most were built after World War II. About 5,000 dams have a height of 60 meters or more; another 350 such giants are currently under construction.

Environmentally, the site where a dam is proposed to be placed and a reservoir created, should not involve ecological disorder, especially in the life cycles of animals and vegetation and man. The

The water retained in the reservoir is later released gradually at a controlled rate according to the carrying capacity of the channel downstream of the detention dam. Thus the area downstream of the dam is protected against flood.

A dam is a barrier designed and constructed to contain the flow of water. It is often built in conjunction with a hydroelectric power station to provide electricity.

A debris dam is constructed to retain debris such as sand, gravel, and drift wood flowing in the river with water. The water after passing over a debris dam is relatively clear.

One of the biggest preparations done for the construction of Hoover Dam was the diversion of the Colorado River away from the site. To make this happen, four diversion tunnels were bored through the canyon walls - two on the Nevada side and two on the Arizona side. On the 1st of February, 1935, a few years after the Colorado River was diverted, a steel gate was lowered down to allow the water to take its natural course again.