Hydro-Flattened Bare Earth DTM. The dataset was created using the lidar bare earth points and 3D hydro breaklines to a resolution of 1 m (April 2018). Voids exist in the data due to data redaction conducted under the guidance of the United States Secret Service. All lidar data returns and collected data were removed from the dataset based on the redaction footprint shapefile generated in 2017. This is a MD iMAP hosted service.