The GTOPO30 dataset for Australia was created entirely from 1:1M DCW contours and hydrography.  The quality of the GTOPO30 DEM is not currentlyadequate to extract hydro lines and drainage divides.  A revision ofGTOPO30 is underway. The DEM for mainland Australia in the revised GTOPO30will be created from higher resolution DEMs.  We are hopeful that this willprovide a better DEM allowing the HYDRO1k data products to be extracted.

Australia's drainage divisions and river basins were formally defined by the Australian Water Resources Council in the early 1960s and, with minor modifications resulting from improved mapping of the inland arid zone area, have been the basis for the study of Australian hydrology since then. The 12 drainage divisions were defined by both the major topographic features of the continent and the main climatic zones to give broadly homogeneous hydrologic regions. Within the drainage divisions the 245 river basins are defined by the major watershed lines.