The impact of vegetation on cover systems is often overlooked, despite its importance for the water balance and long-term mine site performance. A two-dimensional numerical study was conducted on the reclaimed Manitou TSF2 mine site in Québec to evaluate the elevated water table (EWT) technique combined with a fine-grained monolayer and vegetation. Groundwater flow simulations using the SEEP/W finite element model were calibrated with (Ethier, et al., 2021) seasonal vegetation data and validated with a 2022 dataset. The study included three sensitivity analyses with 26 simulations, examining variations in leaf area index (LAI: values from 1 to 9), vegetation height (0.5, 1–5, 9, and 25 m), and the relationship between soil cover fraction (SCF) and LAI (nine relationships). The model effectively reproduced observed data, comparing groundwater levels, volumetric water content, and soil suction values. The LAI variations had a greater influence on EWT performance than the vegetation height and the SCF vs LAI relationship. In all three sensitivity analyses, the average groundwater level dropped below the required performance threshold 15 times out of 104 instances, mainly in sensitivity analysis 1 with varying LAI. The degree of saturation (Sr) value fell below the performance criteria limit five times, all linked to sensitivity analysis 1. The presented modeling framework provides a valuable tool to decision makers in assessing vegetation-related risks at reclaimed mine sites.
