A systematic review of spatial optimisation for urban scale stormwater management

Graphical abstract summarising spatial optimisation in urban stormwater management, highlighting simulation and GIS dominance, design-storm rainfall, catchment-scale applications, common interventions, flood objectives, and governance challenges. Urban stormwater management is increasingly challenged by rapid urbanisation, climate change, and the declining performance of conventional drainage systems. This decline can result from capacity exceedance, pipe and pump failures, blockages, sediment accumulation, inadequate maintenance, and long-term asset deterioration. These pressures have accelerated interest in spatially distributed stormwater-management approaches, including nature-based solutions (NBS) and blue–green infrastructure (BGI). However, despite the growing body of research, no critical review systematically examines how spatial optimisation methods guide the allocation, configuration, and prioritisation of stormwater interventions across urban areas. In this systematic review, 102 simulation-optimisation studies were analysed to examine spatial optimisation of NBS placement and deployment in urban water management systems. The review examined the main elements of spatial optimisation frameworks, including simulation models, optimisation techniques, intervention types, objective functions, and spatial and temporal configurations. This review indicates that spatial optimisation can greatly improve urban stormwater management, though its transition from modelling studies to implementation-ready planning is still incomplete. By integrating current methods, applications, and limitations, this review provides a structured foundation for future methodological development and helps practitioners, policymakers, and decision-makers apply spatial optimisation more effectively when planning urban stormwater management at the catchment scale.