Considering the importance of maintaining the quality and quantity of Hornby Island’s water supplies, and the seasonal differences in the demand, this aquifer vulnerability assessment demonstrates that there are variations in aquifer vulnerability throughout the year. These variations are due to precipitation differences. Unfortunately, the unreliable depth-to-water-table data significantly impacts the spatial accuracy of what areas are vulnerable, and as noted above, fractures have not been included. We have identified these areas in hopes that future work will be conducted in order to provide a more accurate assessment of aquifer vulnerability on Hornby Island.