This work describes an experimental set-up for the simulation of confined and unconfined flow in vertical fractures. The set-up presented here is of exceptionally large scale, as the simulated fracture has a length of 6 m and a height of 1 m; it is used to study the effects of the fracture wall roughness on the fracture hydraulics, and validate existing relations for the estimation of the resistance coefficient. Initial experimental data of water depth, velocity, and head loss are reported, and are shown to be consistent and in agreement with theoretical predictions and similar data available in the literature.