Tarbela Dam Power Capacity, Construction and Global Aids

Tarbela Dam Power Capacity

Overviewof Tarbela Dam

Tarbela Dam is a multi-purpose dam that is twice the size of Mangala Dam, three times the size of Aswan Dam in Egypt and the largest earthen dam in the world. This dam is located in Tarbela, District Haripur, Pakistan.

Location of tabela dam

The Tarbila Dam on the Indus River in Pakistan is the largest embankment dam in the world, and it is the second dam in the world in terms of volume structure. This dam is located in Haripur district of Hazare, about 50 kilometers (31 miles) northwest of Islamabad.

Tarbila Dam is 148 meters (about 485.56 ft) above the riverbed. It provides Tarbila water storage with an area of about 250 square kilometers (97 square miles). The power plant of this dam with a capacity of 4,888 megawatts produces more than 17 billion kilowatt hours of electricity annually.

Water crisisof Tarbela Dam

At the time of partition, the irrigation system established by the British on Lower Sindh and its tributaries was divided into two parts. Pakistan was facing India’s supremacy in terms of water. Pakistan knew that if it did not control the adequate amount of water, it would soon suffer from drought and be destroyed.

Because all its rivers used to come to Pakistan through the territory controlled by India. But the Indus River, which is a large river in terms of water, passes through the territory under the control of India in the Ladakh region. Where it was impossible for India to turn away. If the Indus River is dammed and its water is stored, the water problem will be largely solved.

Selecting Place for Tarbela Dam

The most important issue was the location and Skardu Valley and Bhashah were also considered for this, but there were many issues in their selection. Among them, the movement of heavy machinery, the transport of thousands of workers, and the necessary maintenance were also major issues. Till that time the road was not constructed here. Then this place was such that lived in the yellow of earthquakes and was far away. Due to these issues, they were rejected.

Although the biggest advantage of building a dam here was that the water would be slightly free from silt and sediment. For the construction of the dam and other places were also discussed. There were at least two places in the lower part where a dam could be constructed. But for this, a large cultivable area had to be sacrificed.

Finally, after carefully examining the matter for fourteen years, geologists, hydrologists and economists concluded that the most suitable place for the last high hills in the downstream direction is Tarbila. Where it is easy to reach compared to other places. Because this place is only forty miles away from Islamabad.

It may be more appropriate to fill the upper valleys than the downstream areas to form a lake. Because in this way minimum agricultural land will be under water. There was also a big loss in Tarbila’s election. When the Indus River reaches here, immense amounts of silt and sediment have been added to its waters.

These are the silt sediments that fill the rivers. The heat of the sun, the frost, the humidity and the wind that keeps coming from the mountains. As a result, large chunks of rocky and hard rocks separate from their place and slide into the river. These pieces are transformed into fine particles by the friction of river water.

When the river is blocked, it reduces the velocity of the water and the silt and sediments in the water start settling down and the lake is not able to store the water by filling up with this silt. After independence, due to India’s blocking of water from the eastern rivers, agriculture in Pakistan was suffering from water scarcity and faced great threat. In order to deal with this danger, the government of Pakistan formulated a plan to build a dam in the country.

One of them was the plan to build a dam on the Indus River. For which the areas of Attock, Kalabagh and Tarbela were examined. Finally, in 1952, the location of Tarbela was declared suitable for the construction of the dam. The construction of this dam meant changing the structure of this part of the planet. Two-thirds of the soil excavated from Panama Canal for the Panama Canal was required to build the embankment of the dam.

This embankment was to be about two miles long and raised 500 feet above the course of the river. 186 million of soil and rocks were required for this. About half of the soil was to be obtained by digging tunnels and water channels and the rest was to be dug from other places. Three million cubic yards of concrete was required.

Above the dam, the river Indus had to store eleven million waters by taking the form of a lake fifty miles back where the width of its gorge is less than a hundred yards. During the flood season or when the lake level rises due to monsoon rains or in case of a sudden increase in water due to the breakup of a glacier in the upper region, the excess water from the sub-aqueduct will be discharged into the conventional channel below the dam.

Global aid for tarbela dam

For this, technical and financial support was requested from international institutions and friendly countries. In 1967, the World Bank approved the construction of this dam. Tarbela Development Fund was established in 1968. For which, apart from donations, France, Italy, Great Britain, Canada and the World Bank also approved loans.

In the same year, Tarbela Giant and Nature, a consortium consisting of three Italian and three French companies, was awarded the contract for the construction of the dam. In 1969, a group of seven companies from Germany and Switzerland also joined the consortium. This dam was completed in November 1971 and started working in 1977. However, it was completed in 1984 at a cost of $149 billion.

Objectives of the tarbela dam

The main purpose of Tarbala Dam was to store water for irrigation use. Apart from this, there were other objectives, namely generation of electricity and prevention of floods. By this, protection was provided from melting of glaciers and flooding of Indus River. Its seven doors have a discharge capacity of 650,000 cusecs. In addition, it can discharge 850,000 cusecs of flood water through its nine special gates.

This dam is the second largest dam in the world in terms of water storage capacity. It has a water storage capacity of 169,46,600 square kilometers Ie from 450 km (about 279.62 mi). Its lake depth is more than 1,550 ft (about 472.44 m) and its usable water is 11,62-million-acre feet and it has a power generation capacity of 9,68 MW.

Its dam has a length of 9,000 feet (about 2.74 km), a maximum height of 485 feet (147 meters) and a capacity of 18,60,00,000-acre feet (229 cubic kilometers). The average gross discharge of the Indus River and its tributaries is about 208 cubic kilometers. It can irrigate millions of acres of land. There are four tunnels of 45 feet diameter on the left bank of the river.

The first and second tunnels are connected to the power generating units. The third tunnel is also intended for power generation. The fourth tunnel; 200; is for the purpose of irrigation. 10;44\44;00,00,000 was spent on this project. Apart from irrigation and electricity, fishing industry and tourism etc. have also been boosted by the dam. Electricity is generated by drawing a canal and later installing more turbines at Ghazi Brotha.

Tarbela dam Power generation capacity

The turbines of the hydropower plant are on the right and are 14. These plants have the capacity to generate 3,478 MW of electricity. Four generators of 175 MW each were installed in 1977. Two 175 MW generators, four in 1982 and the remaining two in 1985 were installed in these tunnels. Four generators of 432 MW were installed in these tunnels in 1992.

Four tunnels have been constructed on the left and right side of the valley wall. Among them, three tunnels have been built for the purpose of hydropower. While the water of the fourth tunnel is for irrigation. While the fifth tunnel is being constructed on the left bank of the river. It became operational in 1976 and is mainly used for irrigation purposes.

Important parameters and values of Tarbela Dam are mentioned below.

Advantages and disadvantages of the tarbela dam

Due to the construction of this dam, water and electricity generation on the lower part of the river had positive effects on Pakistan. However, due to water, problems such as sem and thor also arose in Sindh and Punjab. But the most terrible effects were created on the lands of this dam. They had to be expelled from their native areas and start their lives anew in other places.

Most of the victims are not fully compensated by the government. Although 3 colonies are getting development funds in terms of facilities and dam royalties, after 1974, there is no relief for the victims who settled in new villages. Among the new villages settled by the affected people, the names of some famous villages are;

• Pathankot
• Katha Colony
• Sultanabad
• Both
• Islampur Lub Mill
• Atmanabad
• Sultanpur
• Islamkot Bhidian
• A new horse
• Nazrabad

• Tanda Jhari Kiss
• Rafiqabad Swabi
• President
• Pure chicken

Apart from them, the victims of Tarbela are living in different cities of the country.

Life spam of tarbela dam

Since the source of the Indus River is glacial meltwater from the Himalayas, the river contains a large amount of silt, carrying 200 million tons of silt annually. The water storage capacity of Tarbela Reservoir was reduced by more than 33.5%-to-6.434-million-acre feet (MAF) against its original capacity of 9.679-million-acre feet.

The estimated useful life of the dam and reservoir was approximately 50 years. However, estimates have been lower than predicted, and it is now estimated that the dam will have a useful life of 85 years, around 2060. Pakistan plans to build several large dams including the Tarbela Dam. After the completion of Diamer Bhasha Dam, the water load in Tarbela Dam will be reduced by 69%.

Benefits of the Tarbela Dam

Apart from fulfilling the main purpose of the dam i.e. water supply for irrigation, Tarbela Power Station has generated 341.139 billion kilowatts of hydropower since its inception. A record annual generation of 16.463 billion KW was recorded during 1998-99. The annual generation during 2007-08 was 14.959 billion KW while the station shared a peak load of 3702 MW during the year, which was 23.057% of the total WAPDA system pack.

Tarbela-4 Expansion Project

In June 2012, the expansion of Tarbela Dam was planned and PC One was prepared for the project. During his visit to Pakistan in March 2013, US Ambassador Richard Olsen offered assistance for the construction of the project. In September 2013, Pakistan’s Water and Power Development Authority signed a Rs 26.053 billion contract with Chinese firm Sino-Hydro and Germany’s Wuth Hydro to carry out civil works on the 1,410 MW Tarbela-4 expansion project. Construction began in February 2014, and was completed in February 2018.

This project was constructed on Tunnel No. 4 of Tarbela Dam. It consists of three turbine generator units, each with a capacity of 470 MW. The tarbela dam is expected to provide an average of 3.84 billion units of electricity annually to the National Grid. This is intended to help supply electricity during the peak summer months.

The annual benefits of the project were estimated at Rs 30.7 billion. On an annual basis, more than 70% of the water flowing through the Tarbela is released into spillways, while only a fraction of the remaining 30% is used for hydropower generation.

The Water and Power Development Authority in Pakistan says the third and final unit of its 1410 MW Tarbela Fourth Expansion Hydropower Project has been connected to the national grid. With this expansion, the installed capacity of Tarbela Hydel Power Station has increased to 4888 MW.

Financing of Tarbela-4 Expansion Project

The project was initially estimated to cost $928 million, but the cost was reduced to $651 million. The World Bank agreed to provide an $840 million loan for the project in June 2013.

The loan had two components: the first was a $400 million International Development Association loan, to be granted as a concessional loan at a low interest rate. The second tranche consists of $440 million from the World Bank’s International Bank for Reconstruction and Development. Pakistan’s Water and Power Development Authority was to provide the remaining $74 million needed for construction, before the project cost was reduced by $277 million. Interest expense for the loans is estimated at $83.5 million.

Due to the revised low-cost increase from $928 million to $651 million, the World Bank allowed the Pakistani authorities to accelerate the completion of the project by 8 months at an additional cost of $51 million. Pakistani authorities were also allowed to transfer $126 million towards the Tarbela-5 expansion project.

Tarbela-5 Expansion Project

The Tarbela Dam was constructed with five original tunnels, the first three of which were dedicated to hydroelectric power generation, and the remaining two for irrigation use. The first of the two irrigation tunnels is used in the fourth phase expansion project while the second irrigation tunnel will be used in the fifth phase expansion.

The Water and Power Development Authority of Pakistan called for expressions of interest for the Tarbela-5 expansion project in August 2014, and final approval for construction was granted in September 2015.

Tunnel 5’s hydropower project has two main components: power generation facilities and power extraction facilities. Major works included under the project include modification of Tunnel 5 and a new powerhouse and its subsidiary, new 500 kV double circuit transmission line from Tarbela to Islamabad West Grid Station to generate about 1800 GW of electricity annually. New 500 kV Islamabad West Grid Station included.

Construction began in August 2021 and is estimated to take 3.5 years to complete. The project will require the installation of three turbines of 510 MW capacity in Tarbela’s fifth tunnel, previously dedicated for agricultural use. After the completion of the project, the total power generation capacity of Tarbela Dam will reach 6,418 MW.

Financing of Tarbela-5 Expansion Project

In November 2015, the World Bank confirmed that it would finance at least $326 million of the project’s estimated $796 million cost including $126 million in funding of $840 million. Dollars were transferred from the fourth phase of the expansion project when the cost of the project was revised.

In September 2016, the World Bank approved additional financing of $390 million for the Tarbela Dam’s fifth expansion hydropower project that will help increase power generation capacity by adding 1,530 MW to the existing Tunnel 5.

The project will be financed by the International Bank for Reconstruction and Development (IBRD), with a variable spread and tenor of 20 years, including a six-year grace period. It will be the first World Bank-supported project in South Asia to be jointly financed with the Asian Infrastructure Investment Bank (AIIB) providing $300 million and the Government of Pakistan $133.5 million. The total cost of the tarbela dam project is $823.5 million.

See Also:

• 10 Largest Hydropower Plant in the World

Frequently Asked Question (FAQs)

Q: What is Tarbela Dam?

Ans: Tarbela Dam is the world’s largest earth-filled dam built as part of the Indus Basin Project. It provides irrigation water for 3.5 million acres of land and generates 2,400 MW of electricity.

Q: When was Tarbela Dam built?

Ans: The construction of Tarbela Dam started in 1968 and the project was completed in 1984. The dam was constructed in three phases to meet the need to divert the river flow.

Q: What is the height of Tarbela Dam?

Ans: The height from the base of Tarbela Dam is 469 ft (143 m).

Q: How much did Tarbela Dam cost?

Ans: The total construction cost of Tarbela Dam was US$ 2.85 billion which took almost a decade to complete.

Q: What is the capacity of Tarbela Dam?

Ans: The storage capacity of Tarbela Dam is 1 crore 10 lakh 98-thousand-acre feet.

Q: Where is Tarbela Dam located?

Ans: Tarbela Dam is located on the Indus River in Haripur District of Khyber Pakhtunkhwa Province, Pakistan.

Q: What is the importance of Tarbela Dam?

Ans: Tarbela Dam contributes to the economy of Pakistan by providing irrigation water to 3.5 million acres of land and generating 2400 MW of electricity.