This study aims at developing a generalized understanding of the sensitivity of soil moisture patterns in reconstructed watersheds, in northern Alberta, to changes in the projected precipitation in the twenty-first century. The GSDW model is applied to three watersheds using climate scenarios generated using daily precipitation and air temperature output from a global climate model (CGCM3), under A2 and B1 emission scenarios, to simulate the corresponding soil moisture. CGCM3 results indicate an increase in the mean annual temperature for Fort McMurray, Alberta of 3·3 (A2) and 2·4 °C (B1), and an increase in the predicted annual precipitation of 34% (A2) and 8·6% with A2 and B1 emission scenarios, respectively. The GSDW model is used, along with onsite historical data, to downscale A2 and B1 emission scenarios and to evaluate the future hydrological performance of the designated watersheds with respect to soil moisture deficit and actual evapotranspiration using a probabilistic framework. The forecasted maximum soil moisture deficit values based on A2 and B1 emission scenarios are expected to decrease compared to those based on the current, largely because of the expected increase in precipitation rates, associated with an expected increase in evapotranspiration.