Message From Project Director
Despite the abundance of water in the country, Nepal has been utilizing a very small portion of it. Spatial and temporal variation in the availability of water is the main reason of the underutilization of water. Increased use of water can be enhanced through appropriate multipurpose infrastructures. This would allow for optimum management of the needs of all concerned stakeholders and water uses and deliver maximum realization of economic benefits.
Year-round irrigation service is the prime necessity for the agricultural development of Nepal which, in turn, is responsible for the food security of growing population. Hydropower development is another essential sector to fulfill the growing demand of energy for economic development of the country. Diversion of water from large surplus river basin to the deficit river basin by implementing Inter Basin Water Transfer Projects (IBWTP) is the most viable method to address these needs. Such IBWTPs holds potential not only to meet assured year-round irrigation targets but also to provide multiple benefit from generation of much needed hydroelectric energy, fulfilling water need for industrial use and urban water supply as well. Thus, the need of the hour is to develop IBWTPs.
Understanding the importance and need of this, Government of Nepal, through its different policy documents including Irrigation Policy, National Water Resources Strategy, National Water Plan, Periodic Plans, has expressed its priority to develop IBWTPs. Based on this, Department of Water Resources and Irrigation has initiated numbers of such IBWTPs to be implemented which are at various levels of study. Being the most viable among other pipeline IBWTPs such as Sunkosi-Marin, Kali Gandaki-Tinau etc., Bheri Babai Multiple Diversion Project (BBDMP) is the first to be implemented.
Bheri Babai Diversion Multipurpose project (BBDMP), one of the National Pride Projects of the country, is a milestone project for solving the spatial variation of water resources within Bheri and Babai river basin. The project aims to divert 40 cumecs of water from the water surplus Bheri river to water deficit Babai river which is later augmented by headworks of Babai Irrigation Project situated at Babai river to irrigate 51000 hectares of land of Banke and Bardiya district. This project involves the construction of about 15 m high barrage cum bridge over the Bheri river, 12.2 Km long tunnel along the fragile Siwaliks geology, surge shaft, 48 MW capacity powerhouse at the tail end of the tunnel, switchyard and transmission line. On account of the topographical and geological complexity and optimization of risk associated with tunneling, BBDMP planned the construction of the Headrace tunnel at the beginning.
For the given geology and topographical situation of the tunnel alignment, mechanized tunneling method using a suitable type of Tunnel Boring Machine (TBM) and lined with precast concrete segments is found to be the appropriate method of construction. The 12 Km long Headrace tunnel, lined throughout by precast concrete segments with 4.2 m finished diameter is being excavated now. Anticipated major risks such as risks due to highest overburden (820m) and fault zone along first 6 Km (from downstream end) has been overcome. More than 7 Km Headrace tunnel (around 60%) has already been excavated till the end of August, 2018. And the second phase of construction of Headworks and Powerhouse has also been initiated.
TBM tunneling technology being first of its kind in Nepal, it has been felt as a major paradigm shift for the Department of Water Resources and Irrigation to achieve the national agriculture development targets through assured year-round irrigation. This technology has opened up the possibility of its use in similar application in other sectors such as mountain roads, hydropower tunnel, Kathmandu metro, drinking water supply tunnel and others.
The Department of Water Resources and Irrigation is formed merging Department of Irrigation (DoI) and Department of Water Induced Disaster Management (DWIDM) as a process of institutional reform. One of the main objectives of this new department is development of basin diversion and multipurpose water resources projects to achieve year round irrigation and optimum utilization of available water resources. The lessons learned from the development of this project will be the key for future project development in terms of technical capacity building and also helps to increase the confidence level of department. So the development of this project “is not a end but a start” of our journey and this will develop firm foundation for achieving the government’s mission “Prosperous Nepal, Happy Nepali”.
Experience gained through the implementation of this project and encouragement received from the various high-level personalities has highly enhanced our confidence to face the challenges to carry forward such a large project in Nepal. This gave us more energy for the successful completion of the remaining activities. Also, interactions and cooperation with other concerned government agencies, political figures and stakeholders to drive this project is highly appreciable.
I, along with my dedicated team, express humble gratitude to all supporting hands and look forward to receiving continuous support from all the stakeholders in future.