Engineering Diplomacy for Water Sustainability: From Global Indicators to Local Solutions

Sustainable Development Goal 6.4 aims to improve water-use efficiency and reduce water scarcity, yet its implementation is hampered by ambiguities in definitions, limitations in metrics, and misalignments between global indicators and local realities. This paper introduces the Engineering Diplomacy Framework (EDF) as a principled yet pragmatic approach to address these implementation challenges. Building on the Water Diplomacy Framework, EDF integrates engineering reasoning with diplomatic negotiation to reconcile quantitative indicators with contested social values and institutional complexity. We analyze SDG 6.4 using three metaphorical heuristics—“ What is one plus one? ”, “ Where do we put the X? ”, and “ How do we divide 17 camels? ”—to diagnose key gaps in current monitoring frameworks and uncover context-sensitive paths to action. Through comparative analysis of Singapore, Denmark, the Democratic Republic of Congo, and Jordan, we show how EDF helps identify locally meaningful interventions where standardized metrics fall short. We conclude by outlining actionable steps for operationalizing EDF principles in SDG implementation, emphasizing the need to move beyond measurement toward negotiated, adaptive, and equitable solutions to achieve water sustainability goals. This manuscript introduces a novel decision-making framework—Engineering Diplomacy—that explicitly addresses ambiguity and contested values in the implementation of Sustainable Development Goals (SDGs). It offers actionable pathways toward more context-sensitive and politically feasible water governance.