Message From Project Director
Assured round the year irrigation is a basic necessary input for the much needed commercialization of agricultural development of Nepal. Despite abundance of water in the numerous river systems in the country, Nepal has so far has been able to utilize a vey meager percentage for irrigation. Main reason for this underutilization is lack of appropriate infrastructure to manage the huge spatial and temporal variation in the availability of water. Moreover, uncertainties and variation in the onset of monsoon, which is reported to have been aggravated due to change in climate has to be addressed. Thus, there is a need to install appropriate infrastructures to increase cultivation area provided with assured round the year irrigation.
Spatial variation of availability of water is huge. Snow fed perennial rivers originating from high Himalayas which comprise the large river systems (Kosi, Narayani, Karnali and their tributaries) carry abundant surplus water throughout the year whereas water available in spring fed rivers originating in the middle/lower mountain and siwaliks classified as medium type rivers (Maikhola, Kamala, East Rapti, West Rapti, Babai etc), are water deficit rivers which carry far too less water to meet irrigation water requirement in autumn and spring season.
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 the need. Such IBWTPs holds potential to not only to meet assured year round assured 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 to IBWTPs.
Realizing this importance, Government of Nepal has expressed its priority to develop IBWTPs through various policy documents including the Irrigation Policy, National Water Resources Strategy, National Water Plan, Periodic Plans and the annual policy and program of the Government. Of the more than eight IBWTPs under consideration by the Department of Irrigation which are at various level of study, Bheri Babai Multiple Diversion Project (BBDMP), being the most viable is the first one selected for implementation. Others in pipeline such as Sunkosi-Marin, Kali Gandaki-Tinau etc are to follow based on experiences gained from implementation of BBDMP.
The three main infrastructures required to transfer water from Bheri river to Babai river are (i) Diversion Headworks across Bheri river, (ii) 12 Km long Headrace tunnel and (iii) Powerhouse and accessories at Babai river. BBDMP is conceptualized integrating all the three components. However, on account of the topographical and geological complexity and optimization of risk associated with tunnelling, BBDMP is planned for phase wise implementation.
The topography, geology and other technicalities of the tunnel alignment has necessitated use of mechanized tunneling for construction of Headrace tunnel. Tunnel Boring Machine (TBM) will be used for construction of the tunnel for the first time in Nepal. The 12 Km long Headrace tunnel, lined throughout by precast concrete segments with 4.2 m finished diameter will be initiated first and then construction of Headworks and Powerhouse will follow subsequently based on progress of Headrace tunnel. It is anticipated that all major risks such as risks due to highest overburden (820m) and fault zone will be overcome along first 6 Km (from downstream end). Therefore, it is planned to initiate the second phase of construction of Headworks and Powerhouse after construction of headrace tunnel is more than 6 Km.
TBM tunneling technology being first of its kind in Nepal, our efforts over past few years in preparation of the project and initiation of its implementation has been to a large extent a "learning-by-doing" experience. Interactions with number of TBM tunneling experts from around the world, study of relevant documents, information available in internet and observation visit to actual TBM tunneling in action has highly enhanced our confidence to undertake this daunting job. Also interactions and cooperation with other concerned government agencies, political figures and stakeholders has encouraged us to face the challenges in implementation of such a large project in Nepal. Despite the fact that the whole process of procurement of contract for headrace tunnel had to be cancelled not only once but twice on account of which two whole years was lost, the project team bravely maintained its enthusiasm and persevered for the third time after which contract No Civil 01/HRT/BBDMP; Construction of Headrace Tunnel was successfully concluded in January 2015. Despite the offset due to the earthquake in 2015 and the national level political disturbance the works under all fronts within the contract are ongoing smoothly.
I feel extremely pleased that after tireless toil and perseverance through multitude of ups and downs; presently, the peripheral requirements for installation and initiation of tunneling by TBM is almost ready at jobsite. Access road, TBM platform, initial 150 m tunnel, precast concrete segment production plant etc are complete. The TBM is already dispatched from the factory at Shanghai and is expected to arrive at jobsite by September, 2017. Middle of November, 2017 will be the much awaited and talked about date for commencement of tunneling by TBM. I keenly and satisfactorily look forward to the landmark date.
I express my gratitude to all the concerned personalities of the Department of Irrigation, Ministry of Irrigation and Government of Nepal, National Planning Commission who have been ever supportive and encouraging in bringing to the level where we are today. I also feel grateful to the encouraging words from the various high level personalities representing various government including Ministry of the Prime Minister and Council of Ministers, Ministry of Finance, etc during their visit to the jobsite
BBDMP is undoubtedly a mission "Difficult but Possible". The one and only concern with us now is how to successfully complete the tunneling works. I and my dedicated team on our part are fully prepared to face the challenges that may be encountered with a sense of adventure. I look forward to necessary support and most of all confidence and positive attitude over the BBDMP team from all concerned authorities and stakeholders.
Shiv Kumar Basnet