Depth-Area-Duration (DAD) refers to a storm analysis through which a relationship between the precipitation depth, areal extent and storm duration is created. This relationship is a key component in analyzing the flooding potential of a watershed. Since the runoff from the land surface is driven by both the volume of precipitation, which is the product of the precipitation depth and areal extent, and time-span over which that precipitation occurs, DAD relationships provide information for watershed studies. A key characteristic of DAD relationships is that generally increasing areal extent and duration of a storm are associated with decreasing precipitation depths. Given that depth is negatively correlated with area and duration, but runoff is positively correlated with depth and area, there is some combination of depth area and duration at which the largest flood is created. Therefore, a DAD analysis seeks to generate a family of curves to represent the DAD relationship of a prominent historical storm, from which further analysis can be performed to develop design storms.