Content
The WEFE+H Nexus refers to the integrated management and governance of Water, Energy, Food, Ecosystems, and Health. Its starting point is simple: these five domains are deeply interconnected, so a decision or policy in one area will almost always affect the others—sometimes directly, sometimes through delayed or unintended effects. The Nexus approach helps make those links explicit, so trade-offs can be anticipated and co-benefits intentionally pursued.
Five domains, one system
The Nexus can be read as a “system map” of dependencies and impacts:
| Domain | What it depends on / what it influences |
| Water | Essential for food production (irrigation), energy generation (hydropower, cooling), ecosystems, and public health (sanitation, drinking water). |
| Energy | Needed to treat, transport and distribute water and to support food processing/storage; many energy systems also depend on water (cooling, bioenergy crops). |
| Food | Relies on water and energy across cultivation, processing and distribution; it strongly shapes land and water use. |
| Ecosystems | Provide “natural infrastructure” (water purification, flood regulation, soil fertility, climate regulation) that underpins the other sectors. |
| Health | Both an outcome and a feedback factor: clean water, nutritious food and healthy environments support health, while health crises can disrupt services and systems. |
Interconnections and feedback loops (why “Nexus” really matters)
In practice, the Nexus is less about listing sectors and more about understanding mutual dependencies. Water is a key input for both food and energy, while energy is a key input for water services (pumping, treatment, distribution) and for food chains (processing, storage). The Learning Environment also highlights that agriculture is the dominant global freshwater user (often cited at over 70% of global freshwater withdrawals), which makes water–food interactions a major pressure point in many basins.
Two cross-cutting dimensions are particularly important in InnWater’s framing:
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Ecosystems as a foundation: healthy ecosystems regulate flows, support biodiversity and soil fertility, and increase resilience—so they are not just “impacted”, they actively sustain the system.
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Health as outcome and feedback: deteriorating water quality, food insecurity or ecosystem degradation can translate into health impacts, while health emergencies can strain water and food systems.
Systemic impacts (how one decision can cascade)
The Learning Environment uses simple illustrations to show why a cross-sector lens is needed. Increasing bioenergy production, for example, can reduce water availability for food crops, alter land use, and affect ecosystem services. Conversely, restoring wetlands can improve water quality, support food-related benefits (fisheries/agriculture), and reduce disease risks—showing how one intervention can generate multi-sector gains.
From silos to integrated Nexus thinking
WEFE+H is also a governance statement: it responds to the limits of sector-by-sector management, which often leads to fragmented policies, inefficiencies and conflicts (for instance, competition over allocation between agriculture and energy, or land-use tensions between food and bioenergy crops).
In the Learning Environment, the Nexus shift is captured through three ideas (kept deliberately practical):
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Integration: breaking down silos through cross-sector coordination and joint decision-making.
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Synergies and trade-offs: actively identifying win-wins (e.g., reuse) while making tensions explicit and manageable (e.g., hydropower vs environmental needs).
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Systemic solutions: designing policies and investments that deliver benefits across sectors, not just within one mandate.
In short, the WEFE+H Nexus is a practical, holistic lens that helps move beyond fragmented solutions and supports more resilient, equitable, and sustainable governance choices in contexts where water, climate, and competing demands are tightly intertwined.