A Dam Squib On Silt Route

To make things worse, an underground labyrinth pipe in unit IV burst on September 4, leading to complete flooding of the underground power house. A small load of silt obstructed the draft tube gates and backflow from the tail race tunnel. The project has completely shut down since. SJVN authorities say it could take a month. "It's a problem of faulty design coupled with no back-up to face such an eventuality. Major changes will now have to be made," admits Kapoor.

Against this year's target of 7,850 mu (million units) of electricity which Nathpa Jhakri was supposed to produce, it will close the year with just about 4,500 mu. Clearly, the project's seven-storey deep underground desiltation chamber, one of the largest in the world, has failed to contain the problem of silt.

In the post-damage phase, experts are now coming around to the view that the basic fault with the Nathpa Jhakri project is that it has been constructed on a major river channel without managing the upstream areas of the river first. Says M.M. Madan, regional director, National Hydroelectric Power Corporation (NHPC): "When you have such a huge run-of-the-river project downstream, it should ideally be preceded by a combination of smaller storage and run-of-the-river projects in the upstream areas to minimise the inflow of silt." The two other smaller projects upstream of Nathpa Jhakri are also run-of-the-river schemes but it's not enough. Though belated, the government is now planning to build a high-storage dam project of 1,000 mw at Khab, some 12 km from the Chinese border. The advantage of having a storage dam upstream is that it is expected to trap much of the harmful sediment from flowing down. At least six new hydel projects are planned on the Sutlej to tap its immense hydel power potential.

Experts warn that since China had flatly refused to share hydrological information with India even during the Pareechoo lake crisis, there could be more trouble ahead. Says Sudhirendar Sharma, director of the Delhi-based Ecological Foundation and a water expert, "Two disasters in quick succession in the Sutlej basin is indication enough that the 334 glaciers in the river basin may be in a state of grave unrest. There are 24 glacial lakes in the Sutlej catchment which are as vulnerable as the Pareechoo lake, ready to burst at the slightest climatic provocation. The signs are indeed ominous."

Though the SJVN, and the Himachal government, after the initial blame game, have got down to fire-fighting, there is little indication that the more serious long-term causes impacting the Nathpa Jhakri project are being addressed.