Project authority of Punatsangchhu Hydropower Project-1 had gone ahead with its dam’s relocation even after knowing the new location’s depth would be almost similar to the old one.
The dam was relocated in 2013.
A joint audit report, conducted by Royal Audit Authority and Indian audit, says the project’s authority had earlier justified that the new location would have a depth of only 30-40 metre below the riverbed.
However, the Chief Engineer of Central Water Commission’s quote, during a meeting, paints a different picture.
Prior to the relocation, the Chief Engineer is supposed to have said the depth at the new dam site would be as good or as bad as the old location, as per the investigation that was being carried out then.
Drawings of the old dam site suggested a 77-meter elevation below the riverbed while the new site would be at a depth of 75 meter.
The authority had also justified that from the new location it would be easier to reach hard rock and would generate an additional 105-megawatt of energy. They had also said the relocation would cost the project over Nu 1 B.
However, the audit report states that the reasons to relocate the dam was not to generate additional energy but was done due to technical reasons.
According to the audit report, in 2008, the economic affairs secretary had said that the change in location was not made for higher generation aspects, but was done in respect to technical consideration and excessive dam height at the location proposed in the detailed project report.
The main reason for the relocation, the Secretary had said, was that the construction of a gravity dam at a 74 metre depth below the river bed was never done before in the Himalayas and the new location was expected to have a smaller depth.
The new dam site, however, was cleared even before the investigations by the geological survey of India, the audit report stated.
