The National Elevation Dataset (NED) contains the best publicly available elevation data merged into a seamless dataset for the entire United States. In some cases these data contain unwanted artifacts, limiting the quality of standard hydrologic derivatives. The Elevation Derivatives for National Applications (EDNA) project is an interagency effort with the goal of developing a more hydrologically correct version of the NED. This improved NED will be used in the systematic derivation of standard hydrologic derivatives. Methods and tools have recently been developed to facilitate the semiautomatic creation of a hydrologically conditioned NED and hydrologically improved derivatives.