Sustainable irrigation is nexus thinking in action

Irrigation is expanding in many countries in response to climate change and rising food demands. While in the past, most irrigation expansion was for large-scale systems supported by governments and multilateral agencies, the major investors today are farmers who purchase their own technologies and use groundwater as the water source. While there are rewards to reap, without a systemic view of the trade-offs this irrigation boom can also challenge environmental sustainability and equity. Importantly, the interlinkages are subtly different everywhere, so there’s a need to share learning between countries, but also to recognize and study the local context.

A set of tools is emerging to reach that systemic yet local view of irrigation that can help ensure sustainability of our water resources. They were explored in a panel of 10 experts at the 2026 Global Forum for Food and Agriculture, titled Sustainable Irrigation Requires a Water-Energy-Food-Environment (WEFE) Nexus Approach. These tools also underline that after 15 years of WEFE Nexus thinking, the nexus approach is much more than an abstract concept. 

“What it would be good to hear during this panel is success stories which are scalable.” That was the opening challenge issued by Leonard Mizzi, Advisor on Food Systems at the European Commission Directorate-General for International Partnerships. “Scalable, also, in a way which makes markets more integrated, because it’s not irrigation for the sake of irrigation. It’s also for a market-oriented approach to local and regional markets… but also tackling water stress, and factoring in a rights-based approach.”

The panel took on this challenge, using the nexus of small-scale investments in groundwater-fed irrigation to demonstrate how WEFE nexus thinking becomes meaningful when it is translated into action oriented tools, programs, and governance choices, with illustrations from Haiti, Mali and Pakistan. 

The hum of solar irrigation in Pakistan

The case of Pakistan featured at the Forum with the participation of Rana Tanveer Hussain, the Minister for National Food Security and Research as well as Minister of Industries and Production. With support from the CGIAR Initiative on NEXUS Gains followed by the CGIAR Policy Innovations Program, as well as several other partners, the Punjab Irrigation Department has mapped some 1.3 million tubewells largely used for irrigation. A key finding from geotagging these wells was that around 50,000–100,000 solar-powered pumps are now in use, gradually reducing the dependence of greenhouse gas emitting pumps. However, the research also found that 52 percent of the province is in a state of groundwater vulnerability.

Looking across sectors, the government is aware that solar irrigation as a technology is good for promoting renewable energy, with the conversion away from diesel pumps holding the potential to earn carbon credits. On the other hand, the ready energy supply does not encourage water conservation – that may take larger changes in irrigation practices and crop choices. At the government’s request, the WEFE Nexus Policy Area of Work under the CGIAR Policy Innovations Program has developed web-based Solar Suitability Mapping and Solar Irrigation Pump Sizing tools to support the investment decision for installing new solar pumps as well as to better balance water and farming needs. 

Designs for food security and nutrition in Mali

The status of groundwater-fed irrigation development is quite different in much of sub-Saharan Africa, as explained at the event by Ramon Brentführer from Germany’s BGR and Mure Agbonlahor from the African Union Commission. Maps of extreme drought vulnerability in the Sahel and Horn of Africa tell one side of the story, while satellite measurements of groundwater tell another: groundwater levels have actually been rising in places by 20 mm per year while there has been very little groundwater development.

In contrast to Punjab, Pakistan, the map of groundwater irrigation in Mali is almost blank. But not entirely: at the Forum, Katrin Rudolf shared work by KfW under a national program for small-scale irrigation. Besides connecting untapped groundwater sources for improving food security and nutrition, the program also uses agroecological approaches to improving environmental sustainability. To improve nutrition outcomes, KfW supports vegetable gardens for women. Moreover, KfW is now moving toward an enhanced watershed approach as it further examines the WEFE nexus for wider sustainable benefits.

Ecosystems as infrastructure in Haiti

The final case study of Haiti shows how nexus thinking can help maintain vital small-scale irrigation systems in fragile contexts. Forum participant Bettina Iseli described how, over the course of 40 years, Welthungerhilfe has helped build small-scale irrigation systems in the hill region of Haiti that are still operating today. This is not trivial given the context of political instability and economic and climatic stress. The irrigation technologies are simple, but from the very beginning – before the WEFE nexus concept was elaborated – Welthungerhilfe considered the irrigation systems as part of a food security system, taking into account how water is managed, how ecosystems are protected, and how local institutions function.

This meant asking systemic questions: “Is water available across seasons and drought cycles? Is the energy model affordable and maintainable? Does irrigation improve food security and incomes in a fair way? And are ecosystems understood as natural infrastructure?”. In answer, water is being managed from catchment to coast, using concepts from agroforestry and watershed management to control sedimentation from the highly deforested mountains. Institutions have been strengthened, with communities – and crucially women – participating in management committees and with user fees maintaining the systems. The 40-year success illustrates how systemic thinking shifts attention toward sustainability amid challenges.

Sustainability through systems

While small-scale irrigation often only covers fractions of hectares, it represents a potential catalyst for system-wide transformation because it sits right at the intersection of water, energy, food, and ecosystems. The “sustainable” in sustainable irrigation is all about the surrounding systems. As farmers carry irrigation forward at their own scale and with their own resources, how do they balance a range of potential energy sources with limited groundwater, agricultural production with nutrition, and natural infrastructure with community resilience in fragile times? Systemic WEFE nexus answers to these questions don’t have to be abstract. After all, connecting one system to another is exactly what the practical science of irrigation is all about. Taken together, global experience shows that small‑scale irrigation can deliver transformative outcomes when approached through a systemic WEFE nexus lens.

Claudia Ringler is Director of the Natural Resources and Resilience Unit at the International Food Policy Research Institute (IFPRI); Mohsin Hafeez is Strategic Program Director for Water, Food and Ecosystems at the International Water Management Institute (IWMI).

This event was implemented under the CGIAR Policy Innovations Program. We would like to thank all funders who supported this research through their contributions to the CGIAR Trust Fund (www.cgiar.org/funders).