GIS lends itself nicely to surface hydrology. Point and linear feature data such as stream locations, gaging stations, and monitoring sites as well as the associated information for each, can easily be stored and manipulated in a GIS.

Using a standard USGS DEM (surface elevation model), watersheds and sub-basins can be delineated using ArcHydro. The resulting basin attributes, such as area and elevational range, can be used to determine a host of hydrological characteristics for a particular location.

Coupled with precipitation data, a well thought out GIS query can answer a number of surface water questions efficiently and accurately.