Can the traditionally managed FMIS in Nepal be strengthen by incorporating groundwater-based irrigation systems?

Neupane, Nilhari; Shrestha, Shisher; Verma, Shilp. 2023. Can the traditionally managed FMIS in Nepal be strengthen by incorporating groundwater-based irrigation systems? In Pradhan, P. (Ed.). Proceedings of the Ninth International Seminar on Opportunities and Challenges in Irrigation System Management: Context of Governance Restructuring, Climate Change and Migration, Kathmandu, Nepal, 15 May 2023. Kathmandu, Nepal: Farmer Managed Irrigation System Promotion Trust. pp.31-43.

Farmer Managed Irrigated System (FMIS) which is predominantly surface irrigation system in Nepal irrigates 51% of country’s total surface irrigated area. The FMIS system has a century-old history with a network of irrigation infrastructures and robust institutional mechanisms.

However, FMIS faces challenges, with water shortage being a major concern, particularly during the dry season. The effects of climate change, extreme weather events, and socioeconomic developments, such as rising labor migration, have further exacerbated the water shortage. As a result, farmers are unable to maximize their outputs and face difficulties in transitioning to commercial and high-value crops. Additionally, waterrelated disputes, especially among tail users, are evident, leading to labor scarcity and a reduction in the FMIS command area. The FMIS system stands at a crossroads, and failure to address these challenges promptly could result in significant damage costs, including the loss of land and labor productivity, as well as the erosion of social capital and physical infrastructures. Moreover, there have been cases where FMIS canals, known as Raj Kulo, have been converted into roads and other public infrastructures.

In contrast, groundwater development in the Tarai region has been evolving independently. Groundwater resources are extensively utilized by farmers in Nepal's plains, employing various groundwater pumping technologies to meet their irrigation water requirements. However, the development of groundwater faces its own set of challenges, including the need for separate social and physical infrastructures and increasing transaction costs for smooth functioning. Additionally, the higher irrigation costs associated with pumping water from groundwater sources pose financial burdens on independent groundwater users, which could be avoided through integration with the FMIS surface irrigation system.

To address these challenges, the study proposes a holistic and integrated FMIS and groundwater-based irrigation model. This model encourages the conjunctive use of surface and groundwater resources, considering social, economic, and environmental factors simultaneously and utilizing common social and physical infrastructures. During the monsoon season, surface water can be utilized for irrigation crops and also replenishing groundwater reserve. In the summer and winter, when surface water availability decreases, farmers can switch to groundwater to optimize their farm income.

The study combines primary and secondary data. Secondary literature was extensively used to gather information on FMIS, while primary data from six case studies of deep tube wells (DTWs) conducted in the Madhesh Province were collected to gain insights into groundwater use models. Descriptive statistical analysis was employed to compare farm income, labor expenses, irrigation costs, and institutional dynamics between FMIS and groundwater-based irrigation systems. The results indicate the potential benefits and synergies of integrating FMIS and groundwater-based irrigation, which can revitalize FMIS, improve agricultural practices, and enhance farm profitability.

The proposed integrated model offers advantages, such as conjunctive use of surface and groundwater, year-round irrigation, groundwater replenishment during the monsoon season, and the utilization of existing FMIS social and physical infrastructures. While the integration may involve additional expenses, specially primarily installation costs, it is anticipated that the resulting lower labor costs for repairs and maintenance, reduced canal construction expenses, and higher farm profits will offset these initial investments and contribute to the overall sustainability of the agricultural system.

Although the proposed integrated model has not yet been implemented extensively, FMIS and groundwater-based irrigation systems have been piloted and validated separately in the past. Therefore, it is recommended to test the dynamic model in terms of economic and environmental aspects and consider upscaling it to a broader agro-ecological zone.

The findings suggest that integrating FMIS with groundwater-based irrigation presents an opportunity to overcome the challenges faced by both systems in Nepal's Tarai region. By leveraging the strengths of each system and utilizing common social and physical infrastructures, the proposed approach can contribute to sustainable agricultural practices, improve farm profitability, and mitigate water scarcity issues. However, further research, collaboration, and policy support are needed to implement and scale up this integrated model successfully.