Expanding the Power of Tarbela Dam

February 6, 2013


A new hydropower plant will be added to an existing water tunnel at the northeast end of the dam, helping increase generating capacity by a third.

Muzammil Pasha/World Bank

  • Tarbela Dam, built in 1974, is one of the world’s largest dams and supplies 16% of Pakistan’s electricity.
  • As demand for power has increased, the World Bank is helping the government of Pakistan expand the dam’s generating capacity.
  • The hydropower project will shift Pakistan’s power mix away from expensive imported fuel oil needed to run thermal plants, to cleaner, more environmentally friendly sources of power.

TARBELA DAM, Pakistan – When daily power cuts darken their homes, Syed Munsif Shah’s neighbors no longer stare in frustration at Pakistan’s largest dam looming beyond their village.

“Now we know to be patient, that good things are coming with fresh changes at Tarbela Dam,” says Munsif Shah. “In fact, when we look at the dam, we feel pride because we are contributing to our nation.”

Soon, Munsif Shah and his friends, who live in a tiny hamlet called Ghazi just seven kilometers from the dam, will be among the hundreds of workers helping to build an additional hydropower plant at the dam.

Originally constructed in 1974, the Tarbela Dam (map) is the world’s largest earth- and rock-filled structure, standing almost 500 feet high and straddling the Indus River for 9,000 feet. Its existing hydropower facilities supply about 16% of the electricity generated in Pakistan.

But in recent years, the country’s demand for power has risen so dramatically that supply can’t keep up. Load shedding has caused widespread blackouts that reached peak levels in 2011 when power cuts occurred in homes, businesses, factories and industries for an average of eight hours daily. In summer, cuts reached 16 to 20 hours in some areas.

The disruption is causing widespread protests, even violence, particularly in major cities like Karachi and populous areas like Punjab province.

Even in Munsif Shah’s little hamlet just down the road from the dam, load shedding can occur for four to six hours daily, he says. “In our area, there is not quite the same hue and cry, although people do complain because we live so close to the source, but we also know we have been lucky.”

Now they hope the latest expansion plan will benefit them and millions of others across Pakistan.

Called the Tarbela Fourth Extension Project, the plan is to increase the dam’s ability to produce electricity by more than a third (by adding 1,410 megawatts of generating capacity to the current hydropower capacity of 3,478 megawatts).

The new hydropower plant will be added to an existing water tunnel at the northeast end of the dam. Since much of the necessary infrastructure is already in place, costly construction, along with many social and environmental challenges often linked with large dam projects, will be avoided. Construction is expected to be completed in 2018.

The World Bank is contributing funds to the powerhouse extension project.

Gazing past the gravel-covered slope of the dam, where an arrangement of white boulders proclaim the Quran verse: “And He Hath Made Rivers for Service unto You,” Hazrat Omar, Tarbela’s general manager and project director, notes that the additional power plant will especially benefit the impoverished of Pakistan because electricity prices should decline.

“When more power is added, electricity costs will go down,” said Omar.  “This will definitely have a positive impact on the poor.”

The increase in water-generated power will also further shift the mix of Pakistan’s generation capacity away from expensive imported fuel oil needed to run thermal plants. “This will be a cleaner, more environmentally friendly source of power,” Omar said.

" Yes, we most definitely need this power, or we are restricting our country’s economic potential. Industry needs this. The people need this. And so, all these things are in the public interest. "

Hazrat Omar

General Manager and Project Director, Tarbela Dam

Walking through the dam’s existing power plant, visitors can feel the building literally hum as powerful turbines churn the river water before sending its generated power through 10 transmission lines that stretch overhead and spread onward across Pakistan.

In the control room, a few men gauge the plant’s performance on computers, dials and meters. Omar points to a number on a red digital display, explaining that at this moment, the plant is producing less power than is required by consumers. Somewhere in the country the lights probably have gone out.

“Yes, we most definitely need this power,” Omar says, “or we are restricting our country’s economic potential. Industry needs this. The people need this. And so, all these things are in the public interest.”

But power is only part of the original purpose of Tarbela Dam. Only about 30% of the water harnessed by the dam is for power generation. The remaining flow from the Indus River, one of the world’s largest waterways, known locally as the “Abbasin” or father of rivers, is used to irrigate millions of acres, or as much land as the combined area of the Netherlands and Denmark.

The dam also prevents unimaginable devastation, as it did during the 2010 floods, although Omar has since submitted a report requesting further water storage capacity along the river “because with additional storage this disaster and others would be completely avoided.”

Water can kill, but it is also “our survival,” Omar notes. “You might be able to live without electricity but you can’t live without food and water security.”

It is this knowledge that originally led to Tarbela’s creation almost 50 years ago, but it required sacrifice. Munsif Shah’s family was among hundreds that farmed, fished and lived for generations in the valley before the dam came. When water levels are low in spring, the crumbled brick top of a mosque’s water tank can still be seen in the reservoir lake that now spreads behind the dam for 97 kilometers.

“I feel greatly emotional sitting here now on the greatest and mightiest dam of my country and the world,” says Munsif Shah. “But I can still remember being a very small boy when my father and I were cutting grass…It was a sad time when he told me our house and relatives’ homes would be lost.”

Families were compensated, resettled in newly created villages with schools, hospitals, and mosques, and many started working at the dam. Now three generations have been employed there, as laborers, technicians, security, engineers, and more. Munsif Shah works as a personal secretary in administration.

“And now more opportunities are coming with this next extension to the dam’s powerhouse,” he said. More power will be created for Pakistan.

“This is a project for us and we are for them.”