GeometryTemplate.WaterLevel
MDT Description
This property sets what height the sea, lakes, and rivers begin at. Note that all terrain below this level is submerged, i.e. you cannot have a wet lake next to a dry lake bed, nor have a river run downhill or at different levels. SeaFloorLevel determines the deepest anything (e.g. a sub or depth charge) can go.
Source and more details
Additional Description