Advancing the evidence for water, sanitation and hygiene systems strengthening: a Delphi study to define research priorities

Strengthening WASH systems is critical to ensure long-term service reliability, equity, and resilience. However, empirical evidence on WASH systems strengthening remains limited. This study employed a Delphi process to identify high-priority research questions to guide systems strengthening efforts, future investments, and policymaking. This study highlights the growing recognition that WASH systems strengthening requires a broad approach, addressing dynamic linkages between building blocks, context, and stakeholders. It also underscores the importance of improved knowledge sharing to bridge gaps between researchers, implementers, and policymakers and provides a guide to generate evidence that informs sectoral investments and interventions. By addressing key research priorities, it supports evidence-based decision-making to enhance the reliability, inclusion, and sustainability of WASH services. The following organisations were involved: London School of Hygiene & Tropical Medicine, UK, University of Leeds, UK, IRC WASH, Netherlands, WaterAid, UK, Independent Consultant, UK, Rural Water Supply Network, Cranfield University, UK, University of North Carolina at Chapel Hill, USA.