Arctic warming rates are two to four times greater than the global average, leading to environmental change, including permafrost thaw and changes in groundwater flow patterns due to active zone alterations. With permafrost degradation and increased groundwater mobility, exfiltration to northern groundwater-fed lakes may increase with continued warming. The research objective is to use a numerical modeling approach to disentangle the effects of precipitation and warming on active zone groundwater flow for a site in the Canadian High Arctic (63°30′N). The research uses a numerical modeling approach to simulate groundwater flow through a hillslope for future climate scenarios. The modeling tool, SUTRA 4.0, simulates groundwater flow and energy transport with dynamic freeze-thaw processes and is used to simulate a two-dimensional hillslope terminating in a lake. Current depth to permafrost is between 0.5 to 2.2 m. We simulate four cases using downscaled CMIP5 projections using the “business as usual” high-emissions scenario (RCP 8.5): baseline conditions, 2011 to 2040, 2041 to 2070, and 2071 to 2100. Climate projections for the site show increasing mean annual temperatures, decreasing amplitude of annual air temperature, and increasing precipitation. Increased mean annual temperature (as opposed to increased precipitation) and the associated annual active zone development primarily controls the groundwater flow. With warming, the active zone deepens and stays open for a longer period annually, allowing for increasing groundwater flow to the lake. Sensitivity analysis shows that the model outcomes are most sensitive to till permeability, till residual liquid freezing temperature, and model base temperature.