India has approved plans to build the country’s biggest hydropower project in the state of Arunachal Pradesh, the Times of India reports.

The $3.9bn scheme will be built on the Dibang river, a tributary of the Brahmaputra, in the country’s mountainous northeast.

When complete in 2028 it will generate up to 2.9GW of electricity from 12 turbines, and will also moderate flooding during India’s monsoon season.

The project was conceived in the early 1980s. In January 2004, approval was granted for the clearance of a 54 sq km site in Munli village in the Lower Dibang Valley. The government then approved an investment of $186m in planning and preparation in July 2019.

The barrier will be a 278m-high, 375m-long concrete gravity dam, which will be the highest of its kind in India. This will  create a 43km-long reservoir with a gross storage capacity of 3.85 billion cubic metres.

The lead consultant for the scheme is Swedish–Finish design engineer AFRY. It carried out a detailed project report, geotechnical appraisal of the future dam’s foundations as well as the construction and project management planning.