Digital Elevation Models (DEMs) of flat lowlying coastlands are becoming even more important for environmental risk analyses, for example the development of effective plans for flooding protection. The need of information at high spatial resolution over very large areas, of the order of 100×100 km2, practically precludes the use of traditional methods (e.g., leveling and DGPS) due to their intrinsic limitation in covering wide zones and reduces the possibility of using Lidar because of its high cost. Starting from the last decade, space-borne radar sensors have been used extensively for this purpose. The most known is the SRTM (Shuttle Radar Topographic Mission) DEM which covers most of the land area between ±60° latitude. This DEM was generated using singlepass interferometry and is widely available at 3-arc-seconds. In this work, we present the results obtained for the Veneto plain, Italy, using the spaceborne SAR (Synthetic Aperture Radar) crossinterferometry.