Restoring Historical Watercourses to Cities: The Cases of Poznań, Milan, and Beijing

Abstract

The increasing frequency of extreme weather events, combined with the historic degradation of urban water systems, has prompted cities worldwide to reconsider the role of water in urban planning. This study examines the restoration and integration of historical watercourses into contemporary urban environments through blue and green infrastructure (BGI). Focusing on three case study cities—Poznań (Poland), Milan (Italy), and Beijing (China)—this research explores both spatial and regulatory conditions for reintroducing surface water into cityscapes. Utilizing historical maps, contemporary land use data, and spatial planning documents, this study applies a GIS-based multi-criteria decision analysis (GIS-MCDA) to assess restoration potential. The selected case studies, including the redesign of Park Rataje in Poznań, canal daylighting projects in Milan, and the multifunctional design of Beijing’s Olympic Forest Park, illustrate diverse approaches to ecological revitalization. The findings emphasize that restoring or recreating urban water systems can enhance urban resilience, ecological connectivity, and the quality of public space.