Himal Press 
KATHMANDU: A breakthrough has been achieved on the river diversion tunnel of the Sunkoshi-Marin Diversion Multipurpose Project.
The final few meters of the 13.3-kilometer tunnel were completed in the presence of Prime Minister Pushpa Kamal Dahal and other high-ranking officials and high-profile attendees in Sindhuli on Wednesday.
China Overseas Engineering Company is constructing the diversion tunnel. The company deployed a tunnel-boring machine to dig the tunnel.
The total cost of the irrigation component of the project is estimated at Rs 37.3 billion, with Rs 10 billion allocated for tunnel digging alone.
Sunkoshi-Marin is the second river diversion project under implementation in the country after the Bheri-Babai. The tunnel-digging part of the Bher-Babai multi-purpose project has already been completed. However, other works like building a dam, constructing a powerhouse, and diverting water remain incomplete.
Crucial for irrigation in central Tarai districts
The government first mooted the Sunkoshi-Marin Multipurpose Diversion Project in 2016. It aims to divert water from the Sunkoshi River to the Marin River, a tributary of the Bagmati River, and enhance the capacity of the Bagmati Irrigation Project (BIP) to irrigate 122,000 hectares of land in Rautahat, Dhanusha, Mahottari, Sarlahi, and Bara districts.
Water will be diverted into the tunnel by constructing a 12-meter high dam at Kandhune, near the confluence of the Sunkoshi and Tamakoshi rivers.
The tunnel will channel water to Kusumtar in Kamalamai-6 of Sindhuli, where a powerhouse with a capacity of 31.07 MW will be built. The water will then flow into the Marin River and ultimately into the Bagmati River.
A joint venture of Patel Engineering of India and Nepali company Raman Construction has bagged the contract for the hydropower component of the project.
Construction works began in October 2022 and are expected to be completed by 2027, according to project chief Mitra Baral.
The irrigation component of the project is estimated to cost Rs 37.3 billion, while another Rs 46.19 billion will be needed for the hydropower component.
