Digital Elevation Models (DEM) and 3D spatial data plays an important role in typical earth science applications. Numerous simulations, e.g. flood modeling, and spatial analysis, requires very exact terrain data. During the acquisition of these data, for an example by means of laserscanning, very large data sets results due to the high measuring point density (up to four points per square meter). Current classical Geo-Information-System (GIS) software cannot manage the demand of processing and analyzing these massive raw terrain data. A lack of computing power may appear. There is a need for sophisticated data processing techniques. For this purpose the use of Grid Computing is a good choice to accomplish high processing performance and storage capacity. To process these massive raw geodata we develop a range of terrain Web Processing Services (WPS) which are made available as Grid services.