In an ongoing project, a cooperation between the TU/e and the Dutch Department of Waterways and Public Works (Rijkswaterstaat in Dutch, abbreviated to RWS) is established. The project focuses on investigating applicability of synthesis-based engineering in the design of supervisory controllers for bridges, waterways and tunnels. Supervisory controllers ensure correct cooperation between components in a system. The design process of these controllers partly relies on simulation with models of the plant (the physical system). A possible addition to this design process is digital twin technology. A digital twin is a virtual copy of a system that is generally much more realistic than the 2D simulation models that are currently used for supervisory controller validation. In this report, the development of a digital twin of the Swalmen tunnel that is suitable for supervisory control validation is described. The Swalmen tunnel is a highway tunnel in Limburg, the Netherlands. This case study is relevant, because the Swalmen tunnel will be renovated in 2023 and 2028. These renovation projects include updating controlled subsystems in the tunnel, such as boom barriers and traffic lights, and updating the supervisory controller of the tunnel. The digital twin might be useful to aid the supervisory controller design process in these renovation projects.