Dissolved organic carbon (DOC) is an important indicator for drinking water treatability as it participates in processes such as chemical flocculation, contaminant transport, as well as formulation of disinfection byproducts. Studies have shown that wildfires can alter the quantity and quality of DOC, which influences water quality. Quantifying the magnitude of DOC change in response to wildfires would advance drinking water treatment and water supply. In this project, I evaluated catchment DOC concentrations and quality before and after a wildfire which took place in May 2021 in Tomahawk, Alberta. Results showed statistically significant effects (p-value < 0.001) of fire disturbance on DOC change. Average DOC concentration in fire-undisturbed catchments post fire was 5.8 times greater than the baseline and average DOC in fire-disturbed catchments post fire was 7.4 times greater than the baseline. The area burned by the wildfire was ranked the fourth most important variable via a random forest model and its covariance with cropland, settlement, wetland land use variables was 14%. The analysis implied larger capital investments to drinking water processes in the downstream Tomahawk community and attention for maintaining water safety in the near term. In the context of the warming climate, it is necessary to take into account different land usage and make management adaptations accordingly to facilitate the protection of drinking water supply.