The state public works department (PWD) has set monsoon 2026 as the deadline to throw open an under-construction permanent bridge across the Balason river in Mirik as the crucial link between Siliguri and tourist town Mirik.

A temporary bridge, made with Hume pipes and a carriageway with riverbed materials, is now the only connection between Mirik and Siliguri after the earlier bridge — the Dudhia Bridge — was washed away by relentless rain on October 5.

The temporary Hume pipe bridge, now open for traffic, may suffer breaches during spells of heavy rain. Being a low bridge, water flowing in the river may reach the carriageway during heavy rain, said a PWD official. An officer of Darjeeling district police said traffic had to be stopped for a night last week when the water level of the river Balason rose after a downpour.

PWD engineers want the permanent bridge, whose construction began few months back, to be ready by 2026 monsoon so that connectivity between Siliguri and Mirik remains uninterrupted even during heavy rain. “We are targeting July or August 2026,” said a senior
PWD engineer.

A PWD official said the bridge would be built at a cost of ₹54 crore. The temporary bridge, built in about 21 days since the flash floods in early October, cost over ₹1 crore, said an official.

The under-construction bridge will be a two-lane one, with space for one vehicle to move in opposite directions simultaneously. This Hume pipe bridge is also two-lane.

“We have completed one well of the 190-metre-long underconstruction bridge. Three more wells will be built. Above them, the pile and pile cap will be built,” said an engineer.

The construction has, however, been delayed as hard rocks present in sections the river bed made the foundation work impossible.

“We are now waiting for the flow of the river to dry up in few more days. We will see what more can be done. If required, we have to do controlled blasting to drill the bed for making the bridge’s foundation,” said the official.