Progress of the Subansiri Hydroelectric Power Project and all you need to know

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Also called the Lower Subansiri hydroelectric power project, the Subansiri Hydroelectric Power Project is a 2,000MW power plant located on Subansiri River on the border of Arunachal Pradesh and Assam, India’s two north-eastern states. The project is being developed by National Hydro Power Corporation (NHPC), the state-run power company. The project was launched in 2005 and was initially scheduled to be completed by 2010. It however ran into delays due to protests from environmental activists over the dam’s potential environmental impact.

Financing of the project

The Subansiri Hydroelectric Power Project was originally estimated to cost around $1.16 billion according to 2002 price levels. These estimations were however revised to $1.97 billion at 2010 price levels following delays.

The cost of the project was met through 70% equity and 30% debt financing through a term loan. The Indian government allocated budgetary support for the project as part of its equity financing.

2003

In May 2003, India launched plans to develop 50,000MW of hydropower. The Subansiri Hydroelectric Power Project was part of the program. In August of the same year, the government cleared to commence construction. The NHPC started the development of the power project.

2004

In January 2004, the Engineering Construction & Contracts (ECC) division of Larsen & Toubro was awarded a $169 million contract for the civil and structural work related to water diversion, tunneling, and the powerhouse.

2005

In 2005, construction work on the power plant started after delays due to issues with the allotment of land.

2007

The diversion of the river was completed in April 2007. Excavation works were also carried out in the same year.

2008

In October 2008, the dam was subjected to a fresh round of design.

2009

Construction at the dam came to a stop for another five months due to the monsoon season.

2011

In November 2011, some progress was made on dam excavation and associated tunneling works. In December 2011, another round of protests forced the construction of the project to halt again.

2012

As of December 2012, 55% of the project was complete with the excavation of the dam and the powerhouse finished. Only the concreting work was remaining. The diversion tunnel of the river was also complete.

In addition, by December 2012, around 60% of the hydro-mechanical equipment and 95% of the electro-mechanical equipment for the project had been supplied.

2019

In July 2019, the National Green Tribunal gave the project the go-ahead to proceed with construction.  In August 2019, the NHPC signed a memorandum of agreement (MoA) with the Assam Government and obtained approval for the project. Work on the project commenced in October of the same year.