Water seepage to delay full commissioning of PHPA-II

BBS | Samten Dolkar and Changa Dorji | September 24, 2024

The water seepage at the powerhouse of Punatshangchu-II Hydroelectric Project will delay the full commissioning of the project. Initially, the full commissioning was planned for December this year. However, due to the seepage, the project is expected to be commissioned only in the second quarter of next year. This is expected to incur a loss of Nu 1.7bn.

According to the PHPA-II management, after the filling of the water conductor system, water seepage has been occurring in the machine hall of the powerhouse since August 13. The seepage was around four litres of water per second.

However, after the spinning of the two turbines on August 15, water seepage has increased amounting to 20 litres per second where water started to fall on equipment.

As a result, testing and commissioning of these two units are temporarily suspended while the water conductor system will be inspected.

According to the project management, seepage is a general phenomenon in underground powerhouses during the initial charging of the water conductor system.

The project consultant, designers, and senior technical experts will inspect the water conductor system after draining out the water which will take one month. The officials will then carry out rectification works if required.

The dewatering of the water conductor system has already begun.

The project management says the seepage may pose a risk to the control panels and electrical equipment in the machine hall.

Officials are, therefore, installing false ceiling in the machine hall to protect water falling on the electrical equipment for now.

PHPA II has six units and the first two were initially planned to be commissioned by the end of this month, and the remaining units by December.