As part of a Cumulative Hydrologic Impact Assessment (CHIA), the extent of ephemeral, intermittent, and perennial streams should be identified in order to quantify the potential effects of surface coal mining.  However, it is impractical and costly to field map these features over large areas and such activities are influenced by time of year, recent weather events, and individual experience.  The Water Availability Tool for Environmental Resources (WATER) is a TOPMODEL based hydrologic model that incorporates local soils, historical climate, and topographic data to estimate streamflow in ungaged basins.  In addition, the tool estimates water movement across the landscape using the topographic wetness index, providing a mechanism of mapping saturated stream reaches along hollows that may not experience flow during all parts of the year.  A statistical analysis of the extent of saturated stream reaches will be compared with field mapping of individual streams in order to evaluate this hydrologic model as an objective method of mapping the extent of ephemeral stream reaches.