This paper describes the application of a three-dimensional Computational Fluid Dynamic (CFD) model to simulate the Marmore waterfall (Italy), which is part of the complex hydraulic system Nera Velino rivers, Piediluco lake. The domain reconstruction has been performed through a non-conventional photogrammetry topographic surveying. The simulations have been performed employing a CFD model that solves the Navier-Stokes equations with the Large Eddy Simulations turbulence closure scheme and the Volume of Fluid multiphase method to handle the free-surface flow. A good agreement is achieved between the CFD model and the real waterfall flow.