Subansiri Dam gets safety clearance, but commercial operation still uncertain

Guwahati, Oct 26: Following the implementation of suggested safety measures by NHPC, the National Dam Safety Authority has given clearance to the Subansiri Lower Hydroelectric Project. But the date for starting commercial operation is yet to be decided.

NHPC sources told The Assam Tribune that a team of the National Dam Safety Authority visited the dam site last month and after detailed inspection, the required clearance was given. At this moment, three turbines, each with the capacity to generate 250 MW of power, are ready for commissioning and the fourth one will be ready by December. There will be total eight turbines in the project.

Sources revealed that the turbines were earlier tested with air pressure. Now the tunnels and the turbines will have to be tested with water pressure before they are commissioned.

Only after receiving the go ahead from the National Dam Safety Authority, the process of filling up the reservoir has started, but the process is very slow in the initial stages as statutory norms need to be followed.

The total water holding capacity of the reservoir is 1365 million cubic metres. The height of the dam of the project is 205 metres and the water level should reach at least 180 metres to run all the turbines.

Sources said that as of now the water level has reached around 175 meters, which is enough to test the turbines one by one. Testing of the turbines and tunnels, which will take some time, will have to be completed before the project is commercially commissioned.

However, it is not yet decided whether the project will start operation with three turbines or wait for the commissioning of the fourth turbine to start commercial operation, the sources added.