Mangla Dam

The Mangla Dam is a massive multipurpose dam located in Pakistan.

It sits on the Jhelum River. The structure spans the Mirpur District of Azad Kashmir and the Jhelum District of Punjab. As a multipurpose dam, it serves several vital roles for the region. Its primary goal is to manage water for irrigation. It also generates large amounts of hydroelectric power. Additionally, the dam acts as a flood control structure. It holds back water during the heavy monsoon season to prevent downstream flooding.

To manage water, the dam creates a large reservoir. This is an artificial lake that stores surplus river water. The dam's main embankment is an earthfill structure. It uses a clay core to prevent water from leaking through. The shoulders of this embankment are covered with gravel and A-type sandstone. The dam also includes several other parts to manage water flow safely. There is an intake embankment made of earthfill with a B-type sandstone core. A main spillway handles excess water through nine radial gates. This spillway can move 1.1 million cusecs of water. An emergency spillway, which is a weir type, can move 0.23 million cusecs.

Generating electricity is a complex mechanical process. Water from the reservoir enters five steel-lined tunnels. These tunnels are 1,560 feet long and carved into the bedrock. The tunnels lead down to a powerhouse at the base of the dam. Inside the powerhouse, the water flows into ten vertical Francis type turbines. A Francis turbine is a specific type of machine that uses water pressure to spin. Each turbine has an output of 138,000 brake horsepower. These spinning turbines are connected to umbrella-type generators. The generators convert the mechanical motion into electrical energy. Finally, three-phase transformers prepare the electricity for use in the power grid.

The history of the Mangla Dam is tied to international agreements. In 1960, the Indus Waters Treaty was signed. This treaty gave Pakistan the rights to develop the Jhelum, Chenab, and Indus river basins. Before this, Pakistan's agriculture relied on unregulated river flows. This caused problems because water was scarce during critical growing periods. The Mangla Dam was the first of two major dams built under the Indus Basin Project. Construction began in 1961 and finished in 1965.

Binnie & Partners, a British firm led by Geoffrey Binnie, designed the dam. A group of eight American firms called the Mangla Dam Contractors built it.

The scale of the project is truly enormous. The dam was built at a cost of one billion dollars. Funding came from the World Bank and the Asian Development Bank. The construction required massive excavation. Workers moved 120 million cubic yards of earth for the reservoir. They also used 142 million cubic yards of fill and 1.96 million cubic yards of concrete. In 2004, a raising project was started to increase the dam's capacity. This project cost Rs. 101.384 billion. It raised the dam height by 30 feet to a new total of 482 feet.

Raising the dam had significant effects on the local area. The increased height changed the reservoir's capacity. It also helped increase power generation. The project was expected to increase energy output by 12 percent annually. This would raise the installed capacity from 1,000 MW to 1,120 MW. However, this change also affected many people. More than 40,000 people living near the dam were affected by the raising project. The cost for compensation and resettlement was Rs. 70 billion. This included building New Mirpur City and several satellite towns like Islamgarh and Dadyal.

The construction of the dam also caused massive human displacement. When the original dam was built, over 280 villages and towns were submerged. This included the towns of Mirpur and Dadyal. Over 110,000 people were forced to leave their homes. This displacement led to a unique global connection. Many displaced people received work permits for the United Kingdom. Today, there are about 747,000 Mirpuris living in the UK. They make up about 70 percent of the British Pakistani community. Many live in northern cities like Bradford and Birmingham.