Abstract: Fracture and Drainage Density (FD and DD), defined as the total length of fractures and drainages per unit area, respectively are a fundamental property of natural terrain that influences the hydrological reservoir units. Hence, the accurate measurement of the FD and DD is useful for hydrological applications. These measurements were evaluated for the Kanchanaburi area along the Sai Yok Fault, Western Thailand which is dominated by an active fault zone using the Digital Elevation Model (DEM) derived data. Damage zones or highly fractured areas were typically found on the Southwest side of the Sai Yok Fault within which Permian limestone is considered to be highest fractured area compared to the adjacent units. Analysis of the FD and DD provide a simple and more general way to locate hydrological reservoir units in a highly faulting area and allows the examination of a large area at a very reasonable cost. However, the FD analysis from the DEM can only allow the identification of the FD in the two surface dimensions and does not address any FD in the depth dimension. Nevertheless, the changes in the FD and DD of an individual geological unit are generally more useful at a local scale to determine the location of highly fractured structures containing a water reservoir along a fault zone whereas FD and DD changes in an individual fault side influences the fracture connectivity for a water reservoir at a regional scale.