Forest disturbance can have significant impacts on mountain hydrology. With projections of increases in wildfire severity, intensity, and frequency it is important to quantify how wildfire and wildfire mitigation strategies alter the amount of water available for runoff (WAfR) from montane areas, especially in semi-arid environments. This study focuses on forest disturbance impacts on the water balance using eddy covariance flux tower data provided by three AmeriFlux towers; each can be characterized by varying levels of disturbance including a stand-replacing fire, forest thinning, and undisturbed. Individual water balance mechanisms such as actual evapotranspiration (AET) were evaluated pre- and post-disturbance to determine if any relationships emerged. The site experiencing a stand-replacing fire resulted in a canopy composition change and a significant (p < 0.05) decrease in annual, winter, spring, and fall AET after the fire. The thinned site showed a moderately significant (p < 0.1) decrease in annual AET after thinning, though this was likely controlled by the single year immediately after disturbance. Water balance terms in the undisturbed site did not significantly change over the period of this study, yet this site had the most variable WAfR due to the high rate of water use by vegetation and groundwater subsidy which made AET greater than precipitation inputs for multiple water years. Results indicate that changes in canopy composition in Southwestern US forests following a stand replacing fire, drives changes in water fluxes such as AET whereas a site experiencing changes in canopy density saw little change in water fluxes.