It became clear in 2018 that the 1200 MW Punatsangchu I project suffered yet another delay as its last date of completion was December 2022 but this was moved to the first half of 2023 to deal with rectification measures.
However, the latest additional slide problem in the right bank will delay the project all the way to 2024.
The Minister of Economic Affairs Lyonpo Loknath Sharma revealed this during the weekly Friday meet. The Minister said that the project has one of the longest legacies and also had a bad legacy.
He said that following the fresh slide on the right bank he personally visited the site and discussed the matter in the authority meeting.
The mini-slide while being small in itself posed larger questions on the rectification works done on the right bank by WAPCOS first to the later additional work recommended by the Norwegian Geological Institute.
He said that in hydropower construction most of the works are civil works and this often involves working against nature and sometimes something unexpected happens which is termed as a geological surprise.
He said that recent slide happened in a part of the original slide and the slide is not so much the concern as to ensure that there is no damage on the hillock and highway above it.
Lyonpo said that the slide was at the dam area and as the dam is constructed it would take care of this slide but he wanted to ensure that everything is secured and there is a long term solution. The minister said that there will be technical meeting on the 24th of February in Delhi to discuss a solution and holistic approach to the problem. He said so far there are no risks to the highway and hillock above.
The minister said that there is no way to go back and the only option is to come up with a long term and concrete solution based on a long term approach.
The P-1 project has undergone several delays over the years after the slide in the right bank was discovered around July 2013. This was coupled with the dam depth going deeper than the expected 35 meters to around 70 meters.
The first cabinet in June 2008 had given permission to move the dam site to its current location with the understanding that additional power can be produced and that that the dam depth would also be lower than the original site. The proposal for removing the site was given by the PHPA Authority.
A Joint Audit Report conducted by the Royal Audit Authority (RAA) of Bhutan and the Comptroller General Audit of India (CAG) for the period -April 2012 to March 2013 showed that the PHPA, its main consultant WAPCOS and the Central Water Commission (CWC) knew that there were geological weaknesses at the right bank area but still went ahead with the tendering of the dam on the same site in 2009.
A geo technical appraisal report prepared by the Geological Survey of India (GSI) saying GSI had identified some weak geological features at the dam site was deliberated by officials from GSI, CWC and WAPCOS on 10th February 2009. The report pointed out that this may entail additional cost.
The GSI report also said that additional investigations were required for the exact delineation of the weak geological features.
However, instead of conducting further investigations before awarding the tender, in what was both a cavalier and procedurally questionable manner, PHPA’s consultant WAPCOS, on behalf of GSI, issued a clearance for the project dam bids to be opened on 16th February 2009.
Finally, work was awarded by PHPA to the dam contractor Larsen and Toubro on 27th March 2009.
However, an investigation report conducted between 29th April 2009 and 17th September 2009 by GSI showed serious problems in the current right bank of the project.
The project’s original completion date was November 2016 but with repeated delays especially with regard to the right bank area.