TARBELA: With the next general elections in mind, the government has decided to pay $51 million additional cost to Chinese contractors for advancing completion of 1,410MW Tarbela 4th extension project by eight months to June 2017.

Wapda and a consortium of M/s Sinohydro Group of China and Voith Hydro Germany and China signed a formal agreement at the Tarbela Dam on Thursday. The project acceleration programme is estimated to generate $300 million electricity during 2017, according to Wapda Chairman Zafar Mahmood.

Briefing journalists, Tarbela Dam General Manager Iqbal Siddiqui said the acceleration programme had been initiated on the directive of the prime minister.

The original T4 project was estimated to cost $928m, but the project authorities had been able to conclude the project contract at $651m. Since the project cost was much lower than estimates finalised in consultation with the World Bank ($840m), the bank not only approved $51m acceleration programme, but also agreed to divert about $150m, saving another 1,400MW for Tarbela 5th Extension project which is expected to be completed by June 2018.

The existing power house at Tarbela completed in 1974 has the total generation capacity of 3,478MW and it would go up to 4,888MW on completion of T4 in June 2017 and further to about 6,200MW by June 2018.

The T4 project is being constructed at Tunnel 4 of the dam which was originally intended for irrigation, but was later taken up for power generation as country’s electricity demand increased.

The country would get 3,840GWh every year from T4 and it would be available for power supply during peak demand months.

Sedimentation

Mr Siddiqui said that live storage capacity of Terbela reservoir had declined more than 33.5 per cent to 6.434 million acre feet (MAF) against its original capacity of 9.679 MAF because of sedimentation over the past 38 years.

Mr Siddiqui claimed that dredging of silt from the reservoir was almost impossible in view of technical and economic reasons. He said there was an option to flush out the silt through spillways, but it would have damaged Tarbela’s own turbines and also the 1,450MW Ghazi Barotha Hydropower projects downstream.

Another option involved dredging of silt but that was too expensive, estimated at $10-12 billion whereas the total cost of the Tarbela Dam construction was just $2.85bn.

He said the project was originally had a designed life of 30 years, but impressive dam management techniques was resulting in availability of more than 65pc storage capacity even after 38 years.

Tarbela-5

Highlighting the Tarbela-5 (T5) project, Mr Zafar Memhood said that the PC-1 of the project would be approved by Executive Committee of the National Economic Council next month.

The T5 project is meant to generate 1,300MW to 1,400MW after its completion in 2018. The study for the project has been completed with $2.9m financing by the World Bank.

The study allows us to install turbines in Tunnel 5 that will generate electricity up to 1,400MW, lifting the total electricity generation capacity of the Tarbela Dam up to 6,200MW.

“We have conditional offers of euro 300 million for financing the T5 each from Austrian government and M/s Voith Germany if we agree to award them contract,” he said.

Published in Dawn March 7th , 2015

On a mobile phone? Get the Dawn Mobile App: Apple Store | Google Play