–Capacity of 150,000 lakh acre feet lost
Silt deposits in Tunnel 4 of the Tarbela Dam have reduced its water storage capacity, due to which, wastage of around one-and-a-half lakh acre feet annually has so far been anticipated.
Official sources, on the condition of anonymity, informed that water storage capacity of Tarbela Dam was sixty-three lakh and twenty-eight thousand acre feet. But the storage capacity of the reservoir has been reduced to sixty-one lakh and seventy-four thousand acre feet due to Tarbela-4 extension hydropower project (T4HP). Around one lakh and fifty-four thousand acre feet water has been wasted in one year. “Dead level of the reservoir (Tarbela Dam) will have to increase by almost three feet due to silt up in tunnel 4 of Tarbela-4 extension hydropower project (T4HP). The tunnel 4 is closed by WAPDA because a powerhouse is being installed over there under a mega project (T4HP),” sources said.
The sources further said that Superintending Engineer, Survey & Hydrology-Residency Tarbela Dam Project, on 14th February, 2017, had informed General Manager (P & D) WAPDA, Lahore about the status of capacity of the reservoir and had forwarded a capacity table of Tarbela’s reservoir, which was prepared on the basis of hydrographic survey carried out during September-October, 2016.
Tarbela dam is one of the world’s largest structures that not only stores water for irrigation purposes but also generates low-cost hydropower as a by-product. The dam has five tunnels and, currently, hydropower units are installed on four of its tunnels under T4HP project.
The Tarbela Fourth Extension Hydropower Project (T4HP) involves constructing a powerhouse, modifying a tunnel, and installing three 470 MW power units (total of 1,410 MW) on an existing dam located 60 km north-west of Islamabad on the main River Indus by June 2018.
The sources further said that Tarbela-4 extension hydropower project (T4HP) has so far caused reduction the water storage capacity of the reservoir, besides escalating the cost of the project. They said WAPDA (Water & Power Development Authority) chairman has still not taken action against those responsible for delays in 1410 MW Tarbela (4th) Extension Project, even though more than $25 million had been paid in incentive to the contractor for early completion of the project.
Earlier, Prime Minister Nawaz Sharif directed Chairman, Water and Power Development Authority (WAPDA) to determine and fix responsibility for the delays in the Tarbela extension project. Similarly, the PM directed the chairman to take measures for the recovery of payments made to the contractor for acceleration of works on the Tarbela extension project completion by June 2017 (US$25.5 million).
The sources said incumbent WAPDA chairman Lt Gen Muzammil Hussain (R) is reluctant to take action against influential WAPDA officials responsible for delays and heavy incentive payments made to the contractor of Tarbela–4 project. They said the authority (WAPDA) made the approval of incentive payments when Zafar Mahmood was the chairman WAPDA, while incumbent three members of the authority, including Mr Badar-ul-Munir Murtaza, Member (Power), Engr. Muhammad Shoaib Iqbal, Member (Water), and Mr Anwar-ul-Haq, Member (Finance) were also part of the authority. The Authority comprises of a Chairman and three (3) Members working through a Secretary.
The premier had desired to accomplish the 1,410MW Tarbela (4th Extension) Hydropower Project about eight months before the actual deadline of March 2018. Upon this, the completion schedule of the project was squeezed to July 2017. And, the contractor demanded an additional amount of $51m for completing the project in time. Also, $25.5m totally paid to the contractor till February 2016. However, the project cannot meet the deadline.
“The already delayed Tarbela Extension Project (T4HP) might take another year in generating 1,410 MW of electricity,” sources said, adding, “Tarbela – 4 project is likely to complete by February 2018.”
It is also learnt that the first generation unit (470MW) is expected to be completed in August 2017 while completion of the remaining two (each 470MW) in the same month or year not possible. Also, the remaining two units will come online in February and March 2018.
It is worth mentioning here that Tarbela 4 Extension Project (T4HP) was once considered as a low-hanging fruit being the least cost option (around $25 per MWh) for electricity generation. However, the wrong decision of fast-tracking the project and million rupees worth incentive money paid to the contractors for its early completion by the government has so far been proved unrealistic and has escalated the cost of the project.
The Tarbela dam was built in 1974, boasting 3,478MW generation capacity. The decision to complete the Tarbela-4 extension would take the capacity to 4,888MW, with plans to construct the fifth extension also in the pipeline.
