Delta cities are complex systems characterized by continuous change and unpredictable behavior due to global (e.g. sea level rise) and local (e.g. flooding and urban densification) agents. The “living with water” paradigm offers a framework to address these challenges by deploying modular floating infrastructure within urban planning strategies. These solutions boast inherent adaptability and flexibility, materialized by dynamic platforms, allowing for spatial reconfiguration and functional transformation in response to evolving user needs and environmental pressures. The paper discusses the research developments of a planning methodology to facilitate the transition towards “living with water” in delta cities. The methodology leverages scenario creation to enable cities to respond and coexist with uncertainty. The three-stage process begins with designing a planning system based on user activities within functional spaces. Rotterdam serves as a testbed due to its strategic advantages and knowledge of floating solutions for adapting to rising sea level threats. Time-use surveys inform the allocation of functional types on floating platforms, with their distribution determined by frequency of use. Overlaying user flows with accessibility identifies the demand for a specific function over time. In the second stage, the planning system uses reinforcement learning to simulate responses of floating infrastructure to varying demand locations. Then, the system measures de-densification, proximity, and functional object availability over time. This evaluation tool redefines thresholds for functional distribution and demand locations by incorporating scenarios such as seasonal flooding. Such a data-driven performance evaluation facilitates the identification of implementation strategies for cities to develop on water, optimizing urban planning in delta regions to foster resilience, adaptation, and long-term sustainability.