Mega Structure - LARGEST HYDROELECTRIC DAM

Hydroelectric dam that spans the Yangtze River by the town of Sandouping, located in Yiling
District, Yichang, Hubei province, China. The Three Gorges Dam is the world’s largest power station in terms of installed capacity (22,500 MW) but is second to Itaipu Dam with regard to the generation of electricity annually.

Mega Structure 3 - ITAIPU Dam

Vital Statistics:
Location: Brazil and Paraguay
Completion Date: 1991
Cost: $18 billion
Reservoir Capacity: 1.02 trillion cubic feet
Type: Gravity
Purpose: Hydroelectric power
Reservoir: Itaipu Reservoir
Materials: Concrete
Engineer(s): International Engineering Company; Itaipu Binacional

Eighteen was a lucky number for engineers working on the Itaipu Dam. The 4.8-mile-long complex of concrete and rockfill dams on the Upper Parana River at the Brazil-Paraguay border has 18 generators, and it took 18 years and $18 billion to build. The main structure, a hollow, concrete gravity dam, has a powerhouse capable of generating 12,600 megawatts of electricity. That's enough to power most of the state of California. In fact, the enormous dam provides 25 percent of Brazil's energy supply and 78 percent of neighboring Paraguay's energy supply. But building one of the largest hydroelectric dams in the world was not easy.

MEGA STRUCTURE 1- Hoover Dam

Hoover dam is America's most famous landmark, completed in 1935. It was the most colossal structure in the world at that time. This great American icon was to be the largest and heaviest dam, producing the largest amount of Hydroelectric power in the world. 21000 men took part in its construction and of them 112 laid their lives to complete this megastructure. Though its not the superior dam today but still most famous, iconic and greatest dam ever built. Situated in Mojave desert, 30 Km south-east of Las Vegas. Built on Colorado River at Black Canyon, the construction site was extremely difficult. The risks involved were huge and the consequences could have been catastrophic, if the dam failed. Hoover Dam is 221 m high, 201 meters thick and 3.4 million cubic meters of concrete has been used in it.

Why Hoover Dam was Constructed? Colorado, worlds one of the most powerful and unpredictable rivers, would break its banks in every spring and flood the area. The Government instructed the Bureau of Reclamation to come up with a solution and they decided to build world's largest dam. The site chosen for the megastructure Hoover Dam was Black Canyon. It is an 800 ft high deep gorge through which the river flowed. The spot, Black canyon is in the middle of the desert, so there was no infrastructure, no labors, no transportation and the weather too was harsh. Frank Crow, was the Chief Engineer of Hoover Dam and was assigned the job to get it completed in the span from 1931 - 1935. The construction of Hoover took 7 years at a cost of $ 125 million. Nowadays this amount is about 788 million pounds. If the dam was not completed in the given time it would have cost the contractors $ 3000 / day in financial penalties.