Himalayan Glacial Lake Threatens Bihar

A Himalayan glacial lake some 50 km northeast of here could burst any day, unleashing flash floods which could spill over into Bihar, experts have warned.

According to a study by Dr J. Revenberds and experts at the Nepalese Department of Hydrology, the Tso-Rolpa glacier lake, 4,500 metres above sea level in the Rolwaling Valley in Dolkha district, has swollen from 1.37 sq. km. to 1.65 sq. km.

The melting process of the lake, which was detected in 1996, has speeded up along its northwestern side, which experts say can lead to a massive explosion. The lake holds an estimated 80 million cubic metres of water.

If the glacier bursts, 40 million cubic metres of water will gush out, completely inundating 40 small and large villages along the Rolwaling river banks and also the Khimti Hydro Electricity Project, the Manthali airstrip in Ramechhap district and the Tamakoshi and Sunkoshi river banks.

Studies say that the effect of the floods could be felt as far as the Kosi barrage, about 300 km southeast from the lake, with the waters likely to spill over into Bihar.

The Nepalese government has directed local authorities in the area to take precautionary steps to reduce the expected damage.

Experts advise evacuating to safer places at least 70,000 people living in the area expected to be hit by the disaster.

They have asked authorities to move people living along the banks of the Tamakoshi river, where water from the Tso-Rolpa glacier lake enters, at least 20 metres above the river.

A spokesman of the Ministry of Water Resources said that efforts were on to prevent the disaster by using a siphon to release excess water from the lake.

But experts warn that siphoning is not enough. Precautionary measures should be taken on a war footing to let more water out of the lake.

The narrow pipe siphon can do nothing for the present rate of the melting of the ice around the lake, says water engineer Ajaya Dixit.