ISLAMABAD: Chief Executive Officer (CEO), Neelum Jhelum Hydropower Project (NJHEP), Muhammad Arfan Miana on Wednesday hinted at lapses in the design of the project as the experts have identified eleven different possibilities which may have led to blockage and subsequent partial collapse of the tunnel.
Sharing chronology of events with National Assembly Standing Committee on Water Resources, he said on July 4, 2022, excessive water leakage in powerhouse was noticed which was managed by dewatering through pumping.
On July 5, 2022 pressure in the tailrace tunnel increased to 616-m against normal pressure of 600-m due to which load decreased gradually from 696 to 200 MW. Later on pressure in tailrace tunnel was reduced to 601-m to avert damage to powerhouse installations. On July 6, 2022, first load further reduced to 125 MW but later on the powerhouse was shut down completely.
Under the PPRA Rules “emergency clause 42(c) (v)”, original civil works contractor (M/s CGGC) with all drawing, experience and complete understanding of the project was approached to undertake remedial works and the company showed its willingness. Contract was signed on August 5, 2022 which was six months (original estimate) but the scope of the work has been increased during inspection of tunnel after complete dewatering.
Experts identify causes behind NJHPP tunnel collapse
Independent Panel of Experts (IPoEs) has been hired with the following Terms of Reference (ToRs): (i) to ascertain the causes of excessive seepage/ leakage of water in the powerhouse and increase in water pressure in the tailrace tunnel of NJHEP); (ii) to evaluate the structural integrity of the underground works of the project, specially, the tailrace and other; (iii) to identify lapses in design or construction (if any) which caused such blockage and may potentially cause similar failures in future in it and/ or other component; (iv) to suggest remedial measures to resolve current problem in the tailrace tunnel, and reinforcements (if required) in other component of the project; and (v) to provide technical assistance to NJHEP in preparing and pursuing the insurance claim.
IPoEs has opined that there could be eleven different possibilities/ reasons causing the blockage and not a single postulated root cause would be sufficient to cause a tunnel collapse of the magnitude of the one observed in tailrace tunnel. IPoEs’ next visit is scheduled in January 2023.
During discussion, Ch Riazul Haq, MNA who visited river Kunhar as head of Sub Committee, to prepare a report on pollution in the river, informed the committee that he found 189 hotels constructed illegally (without any NOC) on the banks of the river. He revealed that he saw an under construction hotel on the banks of river, which according to him, was owned by a recently retired judge of Supreme Court. He further contended what one can expect from a common man when a judge of the highest court is violating the rules as the hotel was constructed without any approval adding that all hotel waste is being dumped in the river.
Member IRSA Balochistan informed the Committee that his province faces 60 per cent water shortage during the peak season because Sindh does not release its share. However, Member Sindh was of the view that his province intends to give due share of water to Balochistan but it could not do so as it does not receive water from Guddu barrage. He further stated that the height of Sukkur barrage has to be increased to release due share of Balochistan.
Copyright Business Recorder, 2022
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