NGP Standards and Specifications

The Watershed Boundary Dataset (WBD) is a seamless, national hydrologic unit dataset developed using the guidelines and specifications outlined in this document. A hydrologic unit defines the areal extent of surface-water drainage to an outlet point on a dendritic stream network or to outlet points where the stream network is not dendritic. A hydrologic unit may represent all or only part of the t

Hydrographic features derived from U.S. Geological Survey (USGS) 3D Elevation Program data, and collected for use by the USGS, must meet the specifications described in this document. The specifications described herein pertain to the final product delivered to the USGS, not to methods used to derive the hydrographic features. The specifications describe the collection area, spatial reference syst

With the increasing availability of 3D Elevation Program (3DEP) quality high resolution elevation data across the United States and the pressing need for better integrated elevation and hydrography data, the U.S. Geological Survey is developing guidance to improve the horizontal and vertical alignment of these datasets. The U.S. Geological Survey is providing the Elevation-Derived Hydrography—Acqu