A system for identifying water ahead of a vehicle

Method of identifying a body of water, comprising: receiving terrain information, including a stereo image pair of terrain ahead of a vehicle, indicating topography of the terrain; calculating a 3D point cloud for the terrain based on the terrain information; identifying an empty region in the predicted path of the vehicle if the number density of data points in the point cloud in that region is less than a threshold; determining whether the empty region corresponds to water if number of pixels that correspond to specular reflection exceeds a threshold and height difference between at least two locations of the region is less than a threshold; outputting a signal depending on whether water has been identified ahead of the vehicle. Slope of landscape may be determined. Average RGB colour values of pixels in the vacant region may be determined. Disparity of stereoscopic images may be determined. Vehicle speed may be controlled and driver alerted if water is detected. Multi-level surface map, voxel map or elevation map composed of square cells may be created for the terrain. Empty areas may also be slope crests, ditches, over-bright regions, dark regions.