Introduction


Nepal has a great task ahead to enhance the agricultural production by improving and increasing reliable and adequate irrigation facilities to meet the food requirement of the ever-increasing population. So building-up a reliable and year-round-irrigation system, especially in the rural area, is the pressing need of the country to ensure food security and to lower down Is level of poverty, through increased agricultural productivity.

Water resources that are primarily needed for irrigation development are abundantly available in the country if considered on annual basis. It has been estimated that more than 225 billion m3 of surface water is available every year in the country. However, less than 10 % of available water has been so far utilized in the country for the irrigation purpose. Most of the irrigation systems in Nepal draw 5555 from small and medium sized rivers, which Ave sufficient flows during wet months of June to September and dry up or have little discharges during the remaining months. As a result. the farmers of the most of the irrigated areas in Nepal have not been able to irrigate fields at the time when they need the irrigation water at the rnost, thus affecting the productivity, which As been the main cause for low incomes of the farmers.

In order to meet the poverty alleviation targets as laid out in the Tenth Plan and subsequent three-year interim plan, the Department of Irrigation intends to develop irrigation infrastructure wherever it is techno-economically viable. In its with this responsibility the Irrigation Projects Development Division and Sub-division offices of the Department of Irrigation is entrusted to carry out implementation as well s preparation work of irrigation development projects. Various irrigation development programs have been launched; the larger ones are implemented as separate project whereas small projects are implemented in a cluster of sub-projects approach.

In this context, Bheri Babai Diversion Multipurpose Project BBDMP is the first of its kind of inter-basin water transfer project conceptualized to provide round the year irrigation facility to 51,000 A of land of Banke and Bardiya district. Therefore, it has two components i.e. Hydropower and Irrigation. It involves construction of intake at Chiple of Ramghat VDC in Surkhet, 12 km long tunnel across the youngest mountain chain, i.e. Siwaliks, surge shaft and powerhouse at Hattikhal, Bardiya. For the first time in Nepal, Tunnel Boring Machine (TBM) is used to excavate the tunnel through fragile rocks of Siwaliks. Seeing its importance for the overall development of Nepal, Government of Nepal has nominated it for Project of National Pride.

The construction of tunnel is in progress after signing the agreement with MIS China Overseas Engineering Group Co. Ltd. On January 29, 2015. Presently, 100 m of tunnel As
already been constructed. using conventional picking method using the pneumatic jackhammer and TBM is supposed to arrive at the site at the end of May 2017.


As it is a pilot project in terms A use of TOM, inter-basin Water Transfer, its activity is being monitored by different agencies inside the Nepal as well as international level as TBM is used for the first time in Nepal in fragile geotechnical condition.