India wants to fast-track plans to build reservoirs to store water from the Brahmaputra and its tributaries to counter a “worst-case scenario” of China diverting about 80% of the river’s lean season flow in Arunachal Pradesh to irrigate the neighbouring country’s arid regions.
The Brahmaputra originates in Tibet, flows eastward and takes a sharp turn west to reach Arunachal Pradesh where it is called Siang. The river’s water discharge is 18.2 billion cubic metre (BCM) in the lean season — November to April — when it enters the eastern state.
The government is keen on storing the Brahmaputra’s water in case China restricts the river’s flow in the upper reaches. The idea stems from a worst-case scenario assessment based on Chinese plans, a senior official said.
India wants to store around 14.8 BCM of water to drive four proposed hydropower projects on the Siang, Lohit, Subansiri and Dibang rivers in Arunachal Pradesh during the dry winter and spring.
The primary focus is on the 10,000 megawatt Siang project that will have a reservoir to store 9.2 BCM of water.
“The lean season average for Siang at the point it enters India in Arunanchal’s Tuting is 18.2 BCM of water. Then at the next measuring point in Pasighat, it is 22.3 BCM,” an official said.
The reservoirs are likely to help control the annual floods in Assam, the official said.
Harnessing the Brahmaputra for power has been a longstanding plan and it has faced stiff resistance from locals and environmentalists, who argue that dams will inundate large tracts of virgin forests and will remain a huge risk in the highly seismic region.
But fresh reports of Chinese threats to divert the river’s water prompted the Centre to call an inter-ministerial meeting recently to discuss the proposed projects. The governments of Arunanchal Pradesh and Assam were asked to give their opinion on an enhanced compensation package to landowners for the Siang project. The states are yet to reply.
“Earlier, the Siang Upper Storage-I and Siang Upper Storage –II were proposed. Now, an in-principle decision was taken to merge the two projects,” a water resources ministry official said.
“The state government has been assured that funding concerns can be addressed and loans will be available,” another official added.
Funding has been a niggle as investment from abroad for projects in Arunanchal Pradesh raised the hackles of China, which claims 90,000 square km of the state as its own.
Shashi Shekhar, former secretary at the water ministry, called for caution considering the region’s sensitive ecology.
“Holding so much water in a highly tectonic zone can be risky. Much study is required before a final call can be taken. The government should not rush into the projects based on threat perceptions from China,” he said.
According to Shekhar, the government should do a cost-benefit analysis of the project.
But several experts thought India should counterbalance any China’s plans for the Brahmaputra.
Lalit Mansingh, a former foreign secretary, said the country should raise the storage capacity and mount a diplomatic campaign to expose internationally how China “by stealth works on water diversion in Brahmaputra that can affect a lower riparian state”.