A diagnostic framework blue-green infrastructure readiness in developing-country cities

Climate change is intensifying floods and other water-related hazards, exposing the limits of conventional grey infrastructure in developing-country cities. Blue-Green Infrastructure (BGI) offers a promising adaptation pathway, but its implementation depends on more than technical suitability. In many resource-constrained municipalities, BGI uptake is limited by fragmented governance, unstable financing, weak technical capacity, and limited public legitimacy. The Blue-Green Infrastructure Diagnostic Tool (BGIDT) assesses these enabling conditions before large-scale implementation. The tool evaluates readiness across four interdependent domains: policy and governance, economic and financial capacity, technical and environmental capacity, and social and cultural legitimacy. Applied to three Colombian municipalities representing high, moderate, and low institutional capacity, the BGIDT shows that readiness depends on the alignment of governance, finance, technical systems, and social legitimacy. Medellín demonstrates how coordinated metropolitan governance reinforces financial, technical, and social capacity. Neiva and Pitalito illustrate how fragmented authority and unstable resources constrain implementation despite policy support. The BGIDT provides municipalities, funders, and policymakers with a practical framework to identify implementation gaps, prioritise capacity-building, target investment, and monitor readiness over time.