According to the project chief Mitra Baral, the project plans to complete the tunnel digging in the next 18-19 months. The US technology Tunnel Boring Machine (TBM) has been used to dig the tunnel.
"Currently, construction work is being carried out 24 hours a day with 3 shifts of 8-8 hours each," said Baral. " On average, 25 meters of tunnels are being dug every day." "If we do not encounter any geological difficulties or technical problems, the construction will be completed before the contract schedule," he added. The China Overseas Engineering Co won the contract for the construction of a tunnel for the Sunkoshi Marin Diversion Multipurpose Project by offering to do it for Rs 10.05 billion, nearly Rs 6 billion less than the price quoted by the government. The Department of Irrigation signed the project contract with the Chinese company on March 23, 2021. As per the contract, the work must be completed within 3 years of the start of construction. The water from the Sunkoshi will first be diverted to the Marin River in Sindhuli through the 7-meter-wide tunnel before being channeled into the Bagmati River. The water will then be collected at a barrage and distributed to irrigate fields. The tunnel is a part of the multi-billion Sunkoshi Marin Project located in Sindhuli and Ramechhap districts that aims to take water from the Sunkoshi River and direct it into the Bagmati River to irrigate 122,000 hectares of farmland in Rautahat, Dhanusha, Mahottari, Sarlahi and Bara districts in the southern plains. While the 13.3 km long tunnel will be completed within the next two years, the Irrigation Department estimates that the overall project will be fully operational only by 2029. The construction of other structures under the project has not started yet. The project proposes to construct a 12-meter-high barrage across the Sunkoshi River and divert a discharge of 67 cubic meters per second through the tunnel to Kusumtar located in Ward 6 of Kamalamai Municipality. A powerhouse will be built on the Marin River to generate 28.62 megawatts of electricity. A Nepali and Indian joint venture company has been awarded the contract to build the dam and powerhouse of the project. The joint venture (JV) of Nepal's Raman Construction and India's Patel Engineering has won the contract to build the Sunkoshi-Marin diversion dam and power plant for Rs 12.5 billion. The project has already given a letter of Intent (LOI) to the JV company. The contract agreement will be signed within two months, according to the project.
