The proposed Rs 13,000-crore Khab Dam in Kinnaur district in Himachal Pradesh, which would have been the highest in India at 275 metres, has been shot down by the defence ministry because it is "too close to the Indo-China border'. The dam was proposed to protect the 1,500 MW Nathpa-Jhakri and other hydro-electric projects downstream.

Silt brought by the Spiti river, which flows from China, has been cited as the main cause for repeated shutdowns of the downstream projects, such as the Nathpa-Jhakri.

The dam can operate comfortably with silt levels up to 5,500 parts per million (ppm) but this monsoon the Sutlej carried silt levels of up to 43,000 ppm.

Frequent shutdowns of Nathpa-Jhakri have also spelt power shortage for the northern grid because of the silt factor. This year, the Nathpa-Jhakri project has suffered losses of over Rs 100 crore with a shortfall of 1,250 million units.

According to the Sutlej Jal Vidyut Nigam (SJVN), the Khab river, which later joins the Sutlej, brings down excessive silt due to increased construction on the Chinese side.

Not only that, H K Sharma, managing director of the SJVN, says the Khab dam would have protected and extended the life of all projects downstream such as the Bhakra and the Kol dams.

Although Nathpa-Jhakri, having shut down on July 25, resumed electricity production on August 15, its fate remains uncertain with the with the Khab project now stalled.