With several pit-lakes proposed in Athabasca oil-sands region (AOSR) closure designs, region specific information is increasingly necessary. Lake Miwasin is a demonstration-scale pit-lake with a ~9ha constructed upland watershed consisting of 3 built hummocks that slope into adjacent swales for drainage. This watershed is intended to provide adequate water to sustain the water cap of the lake and maintain upland eco-function. With snowmelt identified as an important component of the annual regional hydrology, this two year study aims to evaluate the snow dynamics of the upland to determine its importance for system sustainability. Snow distribution was assessed using field-based snow surveys throughout the snowmelt period in combination with ablation lines, soil moisture and matric potential sensors, and pressure transducer surface runoff flumes. 2022 had higher snow water equivalent (125 mm) than 2021 (85 mm), with accumulation highest in the swales and opportunistic wetlands categorized by low lying topography and taller vegetation. Snowmelt rates were comparable between 2021 (6mm/d) and 2022 (6.5mm/d). Surface runoff was lower in 2022 compared to 2021, despite the higher SWE, due in part to higher infiltration of meltwater in 2022 compared to 2021. Antecedent moisture conditions prior to freeze up appear to drive this partitioning, with higher average rainfall occurring in 2020 and below average rainfall occurring in 2021. Despite the differences in snow conditions and initial lake level, Lake Miwasin reached max capacity in both years following the snowmelt. Indicating that snowmelt dynamics of the watershed are an important component for Lake Miwasin annual sustainability.