Safe embankment dams require adequate freeboard to prevent overtopping, making accurate prediction of windgenerated wave run-up essential for design. The studied Tailings Management Area (TMA), located in Quebec, is contained by several perimeter and internal divider dykes, form three operational basins. For closure of the TMA, a closure structure with an overflow spillway is proposed at the downstream end to safely discharge the Inflow Design Flood (IDF) from contributing catchments. A previous assessment established freeboard requirements of 1.4 m under the IDF and 1.6 m under normal conditions. This reassessment was required due to changes in cover type and the presence of a submerged upstream berm, which may alter wind-wave generation and run-up at the closure structure. The updated design replaces the water cover with a soil cover and growth medium extending to a rockfill berm upstream of the closure structure. During IDF conditions, the pond water level is expected to submerge this berm, which was therefore modelled as a submerged breakwater. Wave transmission was assessed for normal and IDF conditions, including cases of reduced or breached crest elevation. A short-duration wind dataset was analyzed to derive directional wind speed frequencies. 2% exceedance wind speeds and representative fetch lengths were used to estimate wave conditions, and semi-empirical methods were applied to calculate wave transmission coefficients across the submerged berm. Results show coefficients between 0.8 and 1.0, indicating limited wave attenuation. Freeboard estimates for the closure structure were updated accordingly, considering wave transformation, run-up, and the minimal influence of the submerged berm.