A year after Prime Minister Narendra Modi, then campaigning for Lok Sabha elections, assured the people of Arunachal Pradesh that small hydropower projects and renewable energy would be pushed as against large dams, his government has just done the opposite. The ministry of environment, forest and climate change has granted environmental clearance to the controversial 2,880MW Dibang Multipurpose Project (DMP) in Lower Dibang Valley in Arunachal Pradesh. The project, pegged at Rs25,347 crores, would be developed by the National Hydroelectric Power Corporation Limited and according to the clearance letter would take nine years to be completed.

The clearance for the country's largest capacity hydropower project comes in the backdrop of stiff local opposition and multiple rejections by the environment ministry's own expert committees on grounds that the sheer size of the project will adversely impact forests, wildlife and livelihood.

To begin with, the project will be see construction of a mammoth 278 metres tall concrete gravity dam. A vast forest area of 4,577.84 hectares or 45.77 sq.kms, of which major chunks are community forests would be submerged due to the project. In fact, the forest advisory committee of the environment ministry recommended the project for forest clearance last year, even though, they had rejected it twice and even said that the ecological impacts outweight its benefits. In addition, the community forest rights of the Idu Mishmi tribe have not been settled under Forest Rights Act.

The hydel project is located just 11kms from the Mehoa Wildlife Sanctuary that is home to the tigers, leopards, the vulnerable clouded leopard specie and Himalayan black bear. The habitat in the sanctuary is rich in diversity at is changes with increase in altitude and comprises of tropical evergreen and temperate forests. Downstream, the Dibru Saikhowa national park in Assam is also home to tigers, leopards, Bengal florican.

"Downstream, agriculture, wildlife, livelihoods will all be affected. The submergence area is huge and all these impacts have not been considered. The clearance puts a condition of carrying out an impact study five years after work begins, but this should have happened earlier," said Himanshu Thakkar, co-ordinator, South Asian Network on Damns, Rivers and People (SANDRP)

He added, "Those displaced and rehabilitated in the Tehri project are facing landslides in the rehabilitated area. This shows that large dams make the area prone to landslides."

Before clearing the project, no public hearing was carried out in the donwstream areas of Assam while in Arunachal Pradesh, the Idu Mishmi tribes opposed the project during their public hearing. The Peaking power impact of the project too, has not been mapped effectively. During winter, when the Dibang river is stable and farming is also carried out, release of a maximum of 1,400 cubic metre per second of water will have adverse impacts on agricultural lands and wildlife. Also, it makes the downstream region vulnerable to flash floods.

In the light of Nepal earthquakes, it is also important to note that the project site lies on an active fault line. The Great Assam earthquake of 1950, measuring 8.6 on Richter scale is one precedent when it comes to seismic vulnerabilities.

Impacting environmentDuring construction, an estimated 32 lakh truckloads of boulders and 16 lakh truckloads of sand would be extracted from the Dibang river basin, according to South Asian Network on Dams, Rivers and People (SANDRP)

Approximately 198 lakh cubic metres of muck would be disposed in the river bank

This would further impact 120 hectares of the river.

The Idu Mishmi tribes number only up to about 10,000 – 12,000 while a project staff about 6,000 would be working in the region, which may potentially lead to conflicts.