Sponge-City Modelling for EPFL Campus

This master thesis focuses on the development and application of a rainfall-runoff model for the EPFL campus. The goal is to improve water management by applying the principles of the sponge city concept. The project is part of the UrbanTwin initiative, whose objective is to support sustainable urban development and climate adaptation through digital twin technology. The model was built in Python and simulates the water balance on campus. It accounts for runoff from roads and roofs, infiltration into green areas, and storage in a retention tank. The model was calibrated using measured rainfall and flow rate data collected near the SwissTech Convention Center. To test its reliability over time, a 10-year measured rainfall data set was used. The study mainly explores how to reduce uncontrolled runoff by increasing rainwater retention and reuse on campus. Different policies were tested, such as using stored rainwater for irrigation and toilet flushing. The results show that these strategies can significantly lower the failure rate of the tank system and reduce the overall runoff leaving the site. This work contributes to the UrbanTwin project by providing a practical tool to evaluate water management policies at the campus scale. It helps inform decisions aimed at making urban infrastructures more resilient and sustainable.