Farmer-managed irrigation system (FMIS), which is predominantly a surface irrigation system in Nepal, accounts for 51 percent of the country’s total surface irrigated area and contributes significantly to national food security. With roots dating back a century, this irrigation system possesses robust social capital. Moreover, its significance is growing amidst the challenges posed by rising global warming and energy scarcity.

Traditional FMIS faces several challenges such as water scarcity, labour shortages due to outward migration, and increased operation and maintenance costs. As a result, many of them have become defunct or significantly reduced command areas in recent years. An illustrative case is the decline in the number of Rajkulos in Nepal.

While exploring solutions to revive FMIS, one promising solution could lie in integrating it with groundwater-based irrigation systems. Research and pilot initiatives conducted by the International Water Management Institute offer compelling evidence that such integration could effectively address the challenges.

Groundwater-based irrigation systems play a crucial role in addressing the constraints faced by traditional FMIS. According to AQUASTAT, the Food and Agriculture Organisation’s global water information system, groundwater reserves in the country are estimated to be around 8 billion cubic metres, providing a significant potential source of water for irrigation. By harnessing underground water resources, farmers can overcome seasonal variations in water availability, ensuring continuous irrigation and improving crop planning and cultivation practices by incorporating high-value crops into their crop calendar. This would lead to increased crop yields and overall farm incomes.

Integrated approach

In 1995, the Agriculture Perspective Plan envisioned the conjunctive use of groundwater and surface water for FMIS. However, full operationalisation at that time was hindered by challenges such as higher energy prices, lack of technology for pumping and well-developed infrastructures for groundwater irrigation, and lack of solid governance structures at the community level like water user associations.

Moreover, the absence of sufficient access to electricity for agricultural purposes and lack of solar-powered irrigation further hindered the successful execution of the plan. Failure to combine the governance system of FMIS with groundwater renders this concept futile. Fortunately, over the past decade, there have been positive developments. The availability of affordable electricity and the introduction of solar-powered pumps have presented viable options for groundwater extraction. This has paved the way for a more integrated approach that transcends mere conjunctive use. Instead, it advocates for whole system integration, where groundwater leverages the existing infrastructures and social capital of FMIS, creating a more effective and sustainable irrigation framework.

The integration of FMIS and groundwater-based irrigation systems offers a range of economic and environmental advantages by addressing the challenges faced by each system. FMIS, with its existing infrastructure and strong governance, can serve as the backbone for the integrated system. Moreover, excess water during the monsoon can be used to recharge groundwater and maintain stocks for withdrawal during the dry season.

During the dry season, water scarcity in FMIS can be supplemented by groundwater, while in the monsoon, farmlands can be irrigated by surface water. This integration reduces the need for pumping groundwater using expensive energy sources during the monsoon. This integrated approach brings synergy and reduces private costs (such as energy costs for pumping) and environmental costs such as groundwater depletion and emission. For instance, farmers relying solely on groundwater irrigation face high energy costs to irrigate their paddy fields even during the monsoon when water is abundant. However, by integrating the two systems, farmers can avoid these costs during the rainy season, as FMIS efficiently utilises excess water without requiring additional energy. Additionally, grid integration of solar pumps could provide farmers with additional sources of income through net metering during the monsoon season. This would significantly reduce the financial burden on farmers and improve their economic viability.

Furthermore, the adoption of solar-powered groundwater extraction systems reduces reliance on conventional energy sources such as diesel pumps. This not only minimises greenhouse gas emissions but also contributes to the global efforts in mitigating climate change. According to research conducted by the International Water Management Institute, the replacement of diesel pumps with solar-powered alternatives can result in an average reduction of 226.81 kg of CO2e greenhouse gas emissions per year per pump. There are 160,000 diesel pumps in Nepal, and replacing them with electric or solar pumps for pumped groundwater irrigation can significantly reduce greenhouse gas emissions and contribute to achieving Nepal’s nationally determined contribution target.

Local institutions

To ensure full integration of FMIS with groundwater-based irrigation systems, effective governance, policies, regulations and coordination mechanisms need to be established. Strengthening local institutions, such as water user associations, promotes community participation and equitable decision-making processes. Implementing capacity-building programmes that provide farmers and water user associations with the necessary knowledge and skills for managing integrated irrigation practices is essential.

The integration of groundwater-based irrigation systems into Nepal's traditionally managed FMIS holds great potential for revitalising the agricultural sector. This harmonious blend nullifies the drawbacks of both systems, fostering synergy and maximising their benefits. By addressing challenges like inadequate infrastructure, weak governance structures, and high energy costs associated with groundwater irrigation, the integrated approach enables farmers to avoid unnecessary expenses and capitalise on the strengths of both systems. Integrating FMIS and groundwater-based irrigation systems is a timely opportunity in the context of increasing water scarcity, fuel crisis and impact of climate change. To fully harness this potential, it is vital to seize the moment and foster collaboration among stakeholders. By doing so, we can ensure long-term sustainability of Nepal’s agricultural sector and the well-being of its farming communities. This approach paves the way for a promising and resilient future in agriculture, safeguarding food security and supporting the country's overall development.