USGS manages and maintains the National Hydrography Dataset (NHD), which represents the drainage network of the U.S. Its features include rivers, streams, canals, lakes, ponds, coastlines, dams, and stream gages. The NHD is the most up-to-date and comprehensive hydrography dataset for the U.S. With the increasing availability of high-resolution elevation data across the U.S. and the pressing need for better-integrated elevation and hydrography data, the USGS is developing the 3D Hydrography Program (3DHP) to improve the horizontal and vertical alignment of these datasets.

Dewberry is preparing EDH data derived from IfSAR elevation data in Alaska, for the hydrologic unit map-8 (HUC) areas of Utukok River, Kuk River, Northwest Coast, Meade River, Admiralty Bay-Dease, and Mikkelson Bay, covering more than 20,000 square miles. The firm has also been tasked with the preparation of EDH data derived from new lidar elevation data in South Carolina, for the HUC-8 areas of Saluda River, Wateree River, Stevens River, Congaree River, Lake Marion, North Fork Edisto River, and South Fork Edisto River, covering approximately 7,000 square miles.

“Mapping these waterways is an important part of keeping the NHD up to date,” says Dewberry Associate and Project Manager Sue Hoegberg, GISP, CFM. “Identifying the blue lines at a resolution and scale from the most recent elevation data is a critical element of USGS’ vision for the 3D National Topography Model (3DNTM). We are looking forward to using new machine learning tools to derive the blue lines and integrate them into the updated NHD.”