Irrigation in Nepal
Irrigation is the lifeline of agriculture, enabling farmers to grow crops beyond the constraints of seasonal rainfall. In Nepal, where agriculture sustains over two-thirds of the population, effective irrigation is critical for ensuring food security, improving livelihoods, and adapting to climate variability.
This article explores the history, types, current trends, and future prospects of irrigation in Nepal, connecting ancient engineering ingenuity with modern technological advancements.
2. Historical Evolution of Irrigation in Nepal
2.1 Ancient and Medieval Periods
Nepal’s irrigation tradition dates back to the Lichhavi period (c. 450–750 CE), when rulers constructed rajkulo (royal canals) to supply water for farming, drinking, and religious purposes. Notable examples include:
- Tikabhairav Canal in Patan
- Bageswori Canal in Bhaktapur
- Budhikanta Canal in Kathmandu
These canals not only irrigated farmlands but also fed dhunge dharas (stone spouts), ponds, and public water systems, reflecting an integrated water management culture.
2.2 Farmer-Managed Irrigation Systems (FMIS)
Beyond royal initiatives, local communities developed Farmer-Managed Irrigation Systems (FMIS) — small to medium-scale canals built, operated, and maintained by farmers themselves. FMIS governance relied on strong community cooperation, with Water Users’ Associations managing water distribution, repairs, and conflict resolution.
Even today, FMIS irrigate more than 50% of Nepal’s surface-irrigated area, particularly in the mid-hills and Terai.
2.3 Early State-led Projects
In the early 20th century, state-led irrigation began with the construction of the Chandra Canal (1922–1928) in Saptari district, which served thousands of hectares in the eastern Terai. This marked Nepal’s entry into modern irrigation infrastructure.
3. Present-Day Irrigation in Nepal
3.1 Coverage and Limitations
Nepal has significant water resources, yet only 40% of cultivated land is under irrigation.
Only ~19% of agricultural land has year-round irrigation access.
Many systems suffer from low efficiency, siltation, and inadequate maintenance.
3.2 Major Irrigation Projects
Recent decades have seen expansion of large-scale, government-led projects, including:
- Rani Jamara Kulariya Irrigation Project – modernized to serve over 20,000 ha in Kailali district.
- Bheri-Babai Diversion Multipurpose Project – diverts water via tunnel to irrigate 51,000 ha and generate hydropower.
- Sunkoshi-Marin Diversion Project – aims to irrigate 122,000 ha across multiple districts.
- Sikta Irrigation Project – designed for 42,000 ha in Banke district.
4. Traditional Systems Worth Preserving
4.1 Dhunge Dhara (Stone Spouts)
An ancient water delivery system using gravity-fed canals and underground channels to supply public taps. Many have been restored in Kathmandu Valley as cultural and functional assets.
4.2 Rajkulo and Community Canals
Royal canals and locally built channels still function in rural areas, proving cost-effective and resilient against climate variability.
5. Emerging Trends in Irrigation
5.1 Smart Irrigation Technology
Pilot projects are introducing IoT-based water monitoring, automated gates, and real-time data dashboards.
Example: The Babai Irrigation Project now uses digital flow meters to optimize distribution.
5.2 Climate-Smart Agriculture
Irrigation is being integrated with climate-resilient crop varieties, mulching, and rainwater harvesting to reduce vulnerability to erratic rainfall.
5.3 Institutional Adaptation
With rural youth migration, FMIS governance is evolving — women are taking greater leadership roles, and monetary contributions are replacing traditional labor exchanges for canal upkeep.
6. Challenges Ahead
Infrastructure decay due to poor maintenance funding.
Seasonal water scarcity in western Terai and mid-hills.
Institutional coordination gaps between government agencies and local bodies.
Low adoption of modern irrigation technology among smallholders due to cost.
7. The Way Forward
Nepal’s irrigation future lies in blending heritage with innovation:
Preserve and modernize FMIS while expanding large-scale canal networks.
Adopt smart technologies to improve water-use efficiency.
Promote participatory water governance involving farmers, local governments, and private sector actors.
Integrate irrigation with climate adaptation strategies to safeguard productivity under changing weather patterns.
8. Conclusion
From ancient rajkulo and dhunge dharas to satellite-guided drip systems, irrigation in Nepal has undergone profound transformation. The challenge now is to ensure that modernization respects cultural heritage, strengthens community governance, and delivers equitable water access for all farmers.