High intensity short duration (HISD) rainfall events cause extreme flash flood conditions throughout the state of New Mexico resulting in loss of life, property damage, and expensive emergency response. This research describes a distributed hydrological modeling system that estimates discharge from a watershed during HISD rainfall events. The modeling system calculates excess precipitation on impervious and pervious surfaces within the watershed and uses a modified kinematic wave approach to calculate overland flow rates. These overland flow rates are used to calculate travel times from the raster grid cells within the basin to the basin outlet. The model sums excess precipitation based on travel time to the basin outlet through an iterative process to calculate basin discharge. Although improvements are needed for the modeling system, it provides a substantial first step and framework from which to build an effective flash flood prediction tool.