A new water tunnel is currently being designed at the UNFoLD laboratory at EPFL, with the aim to integrate an adaptive roof, in order to create a pressure distribution corresponding to a certain airfoil onto a flat plate, because by this mean the flow of around an airfoil can easily be analysed without having the necessity to build it, saving time. Hitherto, mostly wind tunnels with adaptive walls have been build. Simulations were done to check if the concept of an adaptive wall in a water tunnel is feasible. The results showed that for a small deflection height a sufficiently high pressure drop is achieved. However, the pressure distribution strongly depends on the height, for this reason the adaptive wall has been reconsidered as an adaptive wall instead of a waterproof roof, because this will easily enable the adaptive wall to adjust its height. The bending surface can be accurately controlled with 26 activators. An adaptive wall in a water tunnel is a feasible solution for quick analyses of foils.