Exploring systemic challenges in wastewater reuse for agriculture: A modified Delphi and cross-impact analysis approach

Wastewater reuse stands as a pivotal strategy for addressing agricultural water scarcity; however, its adoption in Brazil remains constrained by interconnected barriers that have been examined in isolation rather than systemically. To bridge this gap, this study identifies and analyzes the interdependencies among barriers to sustainable wastewater reuse in Brazilian agriculture. A mixed-methods approach was employed, integrating a two-round Delphi survey with 40 experts and Cross-Impact Analysis to quantify systemic relationships among 12 barriers across governance, infrastructure, financial, social, and environmental dimensions. The findings reveal a hierarchical structure dominated by governance deficiencies. Insufficient Public Policies (G4) emerged as the dominant driver (Active Sum = 19.04), followed by Absence of National Legislation (G5, AS = 17.76). The analysis uncovered a critical causal cascade: governance gaps propagate through financial constraints (F1) to infrastructure deficiencies, with influence intensities of 2.75 and 2.50 representing the strongest pathways. These outcomes underscore that regulatory reform constitutes the necessary precondition for unlocking investment. The integrated Delphi-CIA framework provides actionable insights for policymakers in water-stressed regions facing similar institutional challenges worldwide. • Governance barriers (G4, G5) dominate as system drivers (Active Sum >17). • Analysis reveals a causal cascade: governance .→ finance → infrastructure. • Financial constraints transmit policy failures with high intensity (2.75). • Infrastructure barriers are reactive outcomes, not root causes. • Delphi-CIA framework identifies leverage points for policy sequencing.