12th Plan stresses hydropower from Yarlung Zangbo

China has given the go-ahead for the construction of three new hydropower dams on the middle reaches of the Brahmaputra river, ending a two-year halt in approving new projects on the river amid concerns from India and environmental groups.

The three new dams have been approved by the State Council, or Cabinet, under a new energy development plan for 2015 that was released on January 23, according to a copy of the plan available with The Hindu.

China has, so far, only begun construction on one major hydropower dam on the main stream of the middle reaches of the Brahmaputra or Yarlung Zangbo as it is known in China – a 510 MW project in Zangmu in the Tibet Autonomous Region (TAR), which began to be built in 2010.

One of the three approved new dams is bigger than the Zangmu project.

A 640 MW dam will be built in Dagu, which lies 18 km upstream of Zangmu. Another 320 MW dam will be built at Jiacha, also on the middle reaches of the Brahmaputura downstream of Zangmu. A third dam will be built at Jiexu, 11 km upstream of Zangmu. The capacity of the Jiexu dam is, as yet, unconfirmed.

The three projects were listed in the State Council’s energy plan for the Twelfth Five Year Plan period (2011-15), which was released on January 23.

Vigorous push

The plan said the government “will push forward vigorously the hydropower base construction” on the middle reaches of the Yarlung Zangbo. In the Twelfth Five Year plan period (2011-15), the government will begin construction of 120 million kilowatt of conventional hydropower.

Feasibility study

A pre-feasibility study report for the 640 MW Dagu dam passed review in November, according to the Huadong Engineering Corporation, a hydropower company that was tasked with conducting the study by the local government.

A notice posted on its website said a two-day review conference for the pre-feasibility study of the dam was held in November, organised by the Tibet Autonomous Region government’s Development and Reform Commission. The notice said the study successfully passed review, adding that the dam would be located 18 km upstream of the already in-construction Zangmu dam.

The catchment area at the dam site, according to the Huadong Engineering Corporation, is 157,400 square kilometres, and the average annual discharge is 1010 cubic metres per second.

The dam will be built with a height of 124 metres and 640 MW capacity. The construction of the Zangmu dam in 2010 triggered concerns in India regarding possible impact on downstream flows. Chinese officials, however, assured their Indian counterparts that the project was only a run-of-the-river hydropower station, which would not divert the Brahmaputra’s waters. The government has also built at least six smaller hydropower projects on the Yarlung Zangbo’s tributaries, which, officials say, will have no impact on downstream flows.

Diversion plan shelved

The government has, for now, shelved a long-discussed plan to divert the Yarlung Zangbo’s waters to the arid north, citing technical difficulties. The plan is part of the proposed Western route of the massive South-to-North diversion project, on which construction is yet to begin. Chinese officials and analysts say a diversion plan is very unlikely, considering the difficult terrain and technical problems.

However, with the three new approvals under the energy plan, four hydropower projects will now be built — all located within a few dozen kilometres of each other — on the main stream of the middle reaches of the Brahmaputra.

Fresh concerns likely in India

While they are run-of-the-river projects, they will be required to store large volumes of water for generating power. Their construction is likely to trigger fresh concerns in India on how the flows of the Brahmaputra downstream will be impacted.