HEC-HMS, the Hydrologic Modeling System, is a utility created so that simulations can be done of precipitation-runoff processes where dendritic watershed systems are concerned. Several types of hydrological problems are meant to be approached using the program, for various geographic areas.
The utility, aimed at the U.S. Army Corpse of Engineers, can be used to approach large river basin water supplies or small watershed runoffs. Its model components are meant to be used in simulations that calculate the hydrologic response in a watershed. These components refer to basin and meteorologic models, input data and control specifications.
With the help of hydrographs that are created by the application, one can perform studies of water availability, forecast flow, analyze the impact of urbanization, and study reservoir spillway design and the reduction of flood damage. Users will probably need instructions in order to learn how to make use of the program, or they can use the guidance offered in the "help" section.
Briefly, HEC-HMS is a modeling system that has the ability to represent several kinds of watersheds and to make calculations and return hydrographs useful in hydrology studies.