The objective of this work is to investigate the impact of a wave farm on the nearshore wave climate quantifying, for the first time, the interaction of the WECs (Wave Energy Converters) with the waves using ad hoc laboratory tests. To accomplish this objective, a procedure consisting of three main steps is implemented and illustrated with a case study: a wave farm of WaveCats (a lateral overtopping WEC) proposed for the Death Coast (NW Spain). First, the wave climate in the wave farm area is characterised and reference wave conditions are established. Second, wave-WEC interaction and, more specifically, wave energy transmission is determined by means of 3D physical model tests. Third, on the basis of the results of the laboratory tests, the impact of different layouts of the wave farm (single-row and two-row arrays) on the nearshore wave climate is computed using a high-resolution spectral wave model. The results indicate that the difference between the two layouts is negligible at a distance of 5000 m or greater past the farm. Although the case study concerns a specific WEC and area of deployment, the procedure is entirely general in that it can be applied to other WECs and areas of interest.