Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) delivered a digital terrain model of a better spatial resolution and accuracy than the traditional free global DEM datasets at near-global coverage and made a wide range of detailed hydrologic applications feasible. In this study, the ASTER data is compared with the digitalized topographic contour DEM in hydrological analysis over the Loukkos catchment in Larache province, Morocco. Extracted stream network and flow directions were compared with the ones derived from the digitalized topographic maps. The result shows, for the stream network, more similarity in average altitude and large differences in lowlands as well as high elevations. For flow directions, the results are almost identical.