Polluted urban water runoff is a significant threat to public health and biodiversity. Changing rainfall patterns causing storm overflows and the discovery of new contaminants are only increasing the problems caused and it is important for urban planners, policy makers and water utilities to work together into order to mitigate the effects of diffuse pollution. One potentially scalable method of mitigation is implementing hybrid Nature Based Solutions (NBS). By identifying and monitoring water pollutants, their sources, and impacts, NBS can be scaled based on social needs, policy, and urban design. The synergies formed, knowledge gained and insights from the three pilot locations will be instrumental in developing hybrid NBS as scalable solutions. This document reports on the stakeholder engagement activities carried out in the first 18 months of the D4RUNOFF project in the three case study sites - Odense (Denmark), Santander (Spain), and Pontedera (Italy). The objectives are to enhance interaction and communication with local audiences to maximize impact, keep stakeholders informed, improve understanding of urban runoff impacts, and promote project results. Key activities include:- Local engagement in case studies through collaborations with authorities and institutions on implementing nature-based solutions (NBS) - Co-design of AI platform user experience through surveys, interviews and workshops with stakeholders (60 engaged) - Open Day in Santander with Climate Fresk workshop, presentations, site visit of NBS, and co-design workshop (50+ participants) - Initial work on gamification challenge and educational game for children - Social media campaigns to raise awareness on urban runoff (example posts shown) Key outcomes are increased awareness of urban runoff issues, input to platform development, and ongoing collaborations to implement NBS solutions. Engagement willcontinue with upcoming Open Days, gamification challenge, educational game session, and social media campaigns. The approach enhances interaction with stakeholders and transfers knowledge on sustainable solutions for urban water management.