Bulletin of Nepal Hydrogeological Association, Vol. 5, September 2020 Maharjan S, Shakya N, 2020 Groundwater irrigation of Bardiya District, Nepal: Status, trends and challenges 1* 2 Surendra Maharjan and Nir Shakya 1 Groundwater Resource and Irrigation Development Division, Banke, Nepal 2 Trichandra Multiple Campus, Ghantaghar, Kathmandu Nepal *Corresponding e-mail: [email protected] Received: 14 April 2020/Accepted: 22 August 2020 ABSTRACT The study attempts to collect scare and scatter data of groundwater irrigation carried by government agencies in Bardiya district. The district lies in the western part of Nepal, Province 5, which is also known as the 'food basket' of the country. In the past few years, there are lots of groundwater irrigation developments in the district. The data of groundwater irrigation shows that there is a rapid growth of groundwater irrigation after 2007. The present article tries to show groundwater status, trends and challenges of groundwater irrigation in the last few decades of the district and also update the groundwater irrigation potential map of the district. Keywords: Groundwater irrigation; development; potential map INTRODUCTION Nepal is primarily an agrarian country, agriculture Groundwater irrigation is carried out by millions development is at its earlier stage in terms of of independent farmers, often with no planning or mechanization, application of various agricultural control on the part of governmental authorities and inputs and availability of irrigation (Chapagain 2018). explains as an excellent catalyst for social and economic A spectacular increase in groundwater use for irrigation transition. According to the Nepal National Sample has taken place in arid and semiarid countries over the Census of Agriculture 2011–2012 (Central Bureau of last few decades. India claims 60% of India’s irrigated Statistics 2012), large part of Nepal’s cultivated land areas are served by groundwater wells; independent area (40%) is reportedly reached by canal irrigation surveys suggest the figure may well be 75%; and schemes, but considerably less is used but an estimated even more, if conjunctive use areas are included. 42% of Nepal Terai’s farmers do have access to Much the same is true of Pakistan, Nepal Terai and groundwater irrigation. Managing scare and scatter Bangladesh. Governments and donors have invested data and keeping records of up-to-date groundwater heavily in building major dams and canal irrigation irrigation status of every district of Nepal Terai play a projects in these regions; but, as of now, by far the bulk vital role in the sustainable development of agriculture of the irrigation and livelihood benefits are delivered and further research in the water resources sector of by groundwater wells (Shah 2005). Groundwater Nepal. So, the article attempts to highlight the status, development is still in the initial stages in Nepal and trends and challenges of groundwater irrigation of last enough groundwater resources to irrigate nearly one- few decades of the district carried out by government half of the agricultural land in Nepal Terai (Kanskar agencies including Department of Water Resources and 2011). According to him, groundwater irrigation can Irrigation, Government of Nepal (GoN), Groundwater play a central role in poverty alleviation and contribute Resource Development Board, GoN and Groundwater to improving food security in the country. Groundwater Irrigation and Development Division Office, Banke, irrigation is also described as a silent revolution and a Province 5 Government. potential source of social conflict (Llamas & Martínez- Santos 2005). 89 Bulletin of Nepal Hydrogeological Association, Vol. 5, September 2020 Maharjan S, Shakya N, 2020 THE STUDY AREA forest. It has 47,233.50 ha agriculture land which is 1.79% to the total agriculture land of the country and The Bardiya District is located in Province 5 in western it is 22.87% of the total land of the district (District Nepal covering 2,06,500 hectares (ha) area (Fig. 1). The Profile 2017). The altitude of this district varies from district consists of eight municipalities out of which 138 m to 1279 m. Elevation decreases from north to 6 are urban municipalities: Gulariya Municipality, south. Tharus are the main indigenous ethnic group of Madhuban Municipality, Thakurbaba Municipality, the district. But in later days, ethnic diversity has been Bansgadhi Municipality, Barbardiya Municipality increased due to in-migration from the outer districts. and Rajapur Municipality and 2 rural municipalities: Karnali River borders west and north, Maankhola River Badhayatal Rural Municipality and Geruwa Rural bordering east, Babai River flows almost in the middle Municipality. The average length of the district is 64 of the district. Most of the surface irrigation projects km and breadth is 35 km. Most of the district (68.76%) are supported by these perennial Karnali, Babai and is low land Terai and the remaining part (31.24%) is Maan Khola rivers. Siwalik Hill and its foothills are almost covered by Fig. 1: Location map. 90 Bulletin of Nepal Hydrogeological Association, Vol. 5, September 2020 Maharjan S, Shakya N, 2020 DEVELOPMENT STATUS, TRENDS 39.60 m. Based on these all investigation GRDP/ GDC, AND PAST EXPERIENCES 1994 published hydrogeological map of the region showing groundwater irrigation potential in the district Bardiya district commonly known as the 'food basket' is 39,582 ha and also categorized STW potential area of the western part of the country is endowed with and DTW potential area. In the case of production enormous storage of groundwater in the form of wells used for irrigation purposes, Irrigation Lind both unconfined and confined states. Department of of Credit Project (ILC) Project and Nepal Irrigation Water Resources and Irrigation and Groundwater Sector Project (NISP), in 1993 were implemented; Resources Development Board (GWRDB), Field the cluster identification programme constructed Office Nepalgunj, Banke, Government of Nepal (GoN) one DTW at Gulariya Municipality which was later are central levels government are for investigation and developed for irrigation purpose for 60 ha land. From research purpose whereas Groundwater Resources 1994 to 2000, 14 DTW irrigation projects namely and Irrigation Development Division Office, Banke the Shantipur-Jamini DTW cluster were constructed is province-level government organization for irrigating 560 ha land. From 2016 to 2018, Irrigation identification of groundwater irrigation potential and Water Resources Management Project (IWRMP) area with development and implementation of deep project constructed 10 DTW irrigating 400 ha in the tubewell (DTW) and STW irrigation schemes. Sanoshree-Taratal area. Besides these, from 2009 to 2019, 16 DTW of 570 ha irrigated land has been In the present context, surface irrigation is constructed under different projects. The total irrigated generally cheaper (it is because farmers have to pay land by 42 numbers of DTW within the last 25 years Irrigation Service Fee (ISF) only) than groundwater is 1,470 ha land. From 1993 to 2019, 6801 numbers but many farmers prefer groundwater in the region of STWs were constructed irrigating 14,619 ha land. because it is easily accessed which is beneath their The total land in the Bardiya district irrigated by small farmland and simple in construction technology groundwater both STW and DTW irrigation project is which makes groundwater obtained individually, 16,089 ha. The year-wise development of groundwater thus bypassing negotiations with other farmers and irrigation with corresponding irrigated land is shown government agencies, often an arduous task. Another in Table 1. more important motive is the resilience of aquifers to dry periods. Farmers also practice conjunctive use There are not any major challenges in groundwater within the surface command area, whenever surface pumping like a decline in groundwater table and no water not available they use groundwater. But the environmental issues due to groundwater overdraft important thing is for many irrigated cash crops, which and no deterioration in quality. It is, therefore, to get usually require large investments from farmers, depend alternative irrigation to surface water or year-round today on groundwater, either totally or on conjunctive irrigation in the district, remaining potential hector of use with surface water. Due to these reasons, there is land as mentioned (around 23,500 ha.) has to be covered high demand in tubewell irrigation in the region there is by shallow or deep tube wells as per the potentiality in a demand of 2660 ha by farmers for the next year 2021 a given map. Farmers of the existing area are much in Groundwater Resources and Irrigation Development more familiar in shallow tube well operation and Office, Banke. its management, in case of deep tube well irrigation system, farmers towards operation and management There are altogether 60 DTWs (Figure 2) in the (O and M) of water distribution is most necessary but district including 19 investigation DTWs of United they are not so well familiar. States Agency for International Development (USAID)/ GoN. Investigations of groundwater in the district The whole package of the DTW system includes were done from 1969 to 1972 under United States DTW drilling (depth varies), electrification with 50 kVA Geological Survey/ Nepal Government constructing 19 distribution transformer, pump house, unplasticized DTWs of an average depth of 160 m and a maximum Polyvinyl