“…These dynamic groundwater flow systems can sustain perennial flow networks between aquifers and surface water bodies through unfrozen pathways (Devoie, Craig, Connon, & Quinton, 2019; Jepsen, Voss, Walvoord, Minsley, & Rover, 2013; Walvoord & Kurylyk, 2016) (Figure 1c,d). However, the overall effect of permafrost thaw on groundwater flow systems, and more particularly on groundwater–surface water interactions, remains unknown, with studies suggesting that these interactions can be highly variable and dependent on the physical setting (Lemieux et al, 2020; McKenzie et al, 2020; Walvoord & Kurylyk, 2016). For example, the impact of permafrost thaw on northern groundwater resources is mixed—some communities will suffer from a loss of surface water availability due to permafrost thaw (e.g., Smith, Sheng, MacDonald, & Hinzman, 2005; White, Gerlach, Loring, Tidwell, & Chambers, 2007), while others may benefit as newly formed aquifers created by permafrost thaw can provide critical drinking water resources (Lemieux et al, 2016).…”