Aboriginal land managers have observed that feral Asian water buffalo (Bubalis bubalis Lydekker) are threatening the ecological and cultural integrity of perennial freshwater sources in Arnhem Land, Australia. Here we present collaborative research between the Aboriginal Rangers from Warddeken Land Management Limited and Western scientists which quantified the ground-level impacts of buffalo on seven perennial freshwater springs of the Arnhem Plateau. A secondary aim was to build the capacity of Aboriginal Rangers to self-monitor and evaluate the ecological outcomes of their land management activities. Sites with high buffalo abundance had significantly different ground, ground cover, and water quality attributes compared to sites with low buffalo abundance. The low buffalo abundance sites were characterized by tall herbaceous vegetation and flat ground, whereas wallows, bare ground, and short ungrazed grasses were indicators of sites with high buffalo abundance. Water turbidity was greater when buffalo abundance was high. The newly acquired monitoring skills and derived indicators of buffalo damage will be used by Aboriginal Rangers to assess the ecological outcomes of their future buffalo control efforts on the Arnhem Plateau.