Jan Willem Kooiman is a senior geohydrologist and has worked ‘in groundwater and subsoil’ for more than 30 years. Following a period working as a researcher, he has worked as a project manager for 20 years and as a Geohydrology team leader for 10 years. He has extensive experience in initiating, leading and carrying out multidisciplinary projects. The focus is mainly on subsoil storage of (fresh) water and energy, salinisation of groundwater, artificial infiltration, groundwater quality and well system management. When doing so, he integrates the technical aspects such as quality and quantity with the policy, management and society aspects. He was closely involved in the recent developments of the Subsurface Water Technologies: Freshkeeper, Freshmaker, ASR-Coastal and HDDWs (horizontal directional drilling wells). As team leader and project manager, Jan Willem leads a large group of professionals and in doing so seeks the right balance between encouragement, direction and guidance. He leads large-scale, integral projects such as Circular Freshwater Supplies for (Greenhouse) Farming, Sustainable Airports Water-Energy-Nexus and Blue-Green roof systems. Jan Willem is also the programme manager of Drinking Water, the Joint Research Programme for Dutch water companies. His passion is organising and connecting researchers and water pipeline professionals to enable them to work together to generate good research results. He often provides process supervision of meetings in the event of problems or creative challenges.