"Assam CM Himanta Biswa Sarma announced that PM Modi has approved the integration of a rail link into the Gohpur–Numaligarh underwater tunnel project."

Assam Chief Minister Himanta Biswa Sarma recently said that Prime Minister Narendra Modi has approved the inclusion of a railway component in the proposed Gohpur–Numaligarh twin-tube underwater tunnel project across the Brahmaputra river, significantly expanding the scope of the strategically important infrastructure initiative.

Speaking to reporters in Guwahati, Sarma said the proposal to include rail connectivity was made by the Prime Minister during Cabinet-level discussions. “When the matter came up in the Cabinet, the Prime Minister proposed that provision for railways must also be made in the project,” he said.

Originally estimated at ₹12,000 crore, the project cost has now been revised to around ₹20,000 crore following the addition of the railway component. Sarma said the Finance Ministry has already cleared the project and Union Cabinet approval is expected shortly. The detailed project report (DPR) has been revised to incorporate the railway line, and the Public Investment Board (PIB) approved the project on December 19.

The twin-tube tunnel, which will carry both road and rail traffic, is expected to be completed within five years. It is considered strategically significant due to its proximity to Arunachal Pradesh, which shares a border with China, and has been planned with national defence and security considerations in mind.

The depth of the tunnel highlights the engineering challenge involved. According to officials, the top of the tunnel crown will be located approximately 32 metres below the lowest bed level of the Brahmaputra, which is particularly deep in this stretch. The Gohpur–Numaligarh corridor will follow a greenfield alignment beneath the river.

Sarma said the idea of an underwater tunnel across the Brahmaputra initially seemed ambitious. “I was thinking whether, like the Atal Tunnel in Jammu and Kashmir, we could have a tunnel under the Brahmaputra where both vehicles and trains can move,” he said, adding that the project would bring the river’s north and south banks significantly closer.

In addition, the Chief Minister said Prime Minister Modi is expected to lay the foundation stone for the ₹6,900-crore Kaziranga Elevated Corridor project, spanning about 34.45 km, on January 17 or 18. He also announced that in February, the Prime Minister will lay the foundation stone for a new railway line between Kokrajhar in Assam and the Gelephu Mindfulness City in Bhutan.