The impact of a changing climate combined with a more urbanized world signals a change in watershed behavior. This work aims to quantify the change in watershed runoff due to both climate change and land use shifts by modeling changes in peak flow rates, duration of storm runoff, and the time to peak flow in response to storms of differing frequencies. GISHydro and WinTR-20 were used in tandem to model the effects of urbanization and increased rainfall predicted at mid-21st century on six small watersheds in two geographic regions of Maryland. Results indicate that climate change is the more influential factor in altering runoff for events from 50% to 1% annual exceedance probability; however, land use change is most prominently felt during the more common storms. Furthermore, a non-linear relationship is observed between the effects of impervious surface and rainfall on the runoff potential of the watersheds.