Diagnosing governance and data gaps in urban groundwater management with a transferable workflow based methodology evidenced in Munich

Abstract Urban groundwater management is emerging as a critical sustainability challenge in European cities under accelerating pressures of climate change and urbanization. Despite substantial investment in monitoring infrastructure and technical expertise, effective groundwater management remains constrained by institutional fragmentation across multiple departments and authorities with dispersed responsibilities, disconnected data systems, and limited coordination. In the two Munich processes examined, the main barrier lay not in technical knowledge, but in institutional governance. The objective of this paper is to develop and demonstrate a methodology that improves the institutional governance of urban groundwater management. The paper applies a four-step Data-Governance Diagnostic combining stakeholder engagement, data assessment, governance workflow analysis, and prioritization of critical gaps, illustrated through two Munich application cases: rainwater infiltration under the Sponge City strategy and thermal groundwater use under the Municipal Heating Plan. Findings show that recurring problems, fragmented data infrastructures, limited digitalization, and data-sharing restrictions, are symptoms of deeper governance weaknesses. Groundwater data can only deliver practical value when embedded in governance systems that enable coordination, accessibility, and effective use in decision-making. The novelty is threefold: a practitioner-friendly step-by-step diagnostic applicable directly by municipalities; a structured output making principal data and governance gaps explicit and actionable; and the demonstration that these gaps are mutually reinforcing and must be addressed simultaneously. Future research should validate the methodology across cities of varying size, institutional capacity, and stage of urban development outside the Alpine context. An interactive workshop-based tool is currently under development to support application in observer cities. A key open scientific question emerging from the Munich cases is whether rainwater infiltration measures produce measurable effects on groundwater recharge at city scale, it remains unclear both how much these measures actually contribute to recharge and whether this contribution is large enough to be relevant for groundwater management. Resolving this requires dedicated city-scale monitoring and quantitative assessment.