Culverts and Drainageways

The hydrographic features defined by this specification are intended to be suitable for elevation surface treatments such as hydroenforcement. A hydroenforced elevation surface is used to model the flow of water over the surface. For a surface to be suitable to model the flow of water, areas within a bare-earth DEM that create a blockage to flow through the surface must be removed. The most common surface features that block flow across a DEM are roads or railroads. Finding the location of culverts and small bridges within a surface beneath transportation corridors or other features is a critical step in hydroenforcement.