National Hydrography Dataset (NHD)

The National Hydrography Dataset (NHD) is a detailed digital map that shows the locations and characteristics of water features across the United States, such as rivers, lakes, streams, and wetlands. It provides authoritative information used by government agencies, researchers, and planners to manage water resources, support environmental protection, and facilitate flood planning. The NHD includes data on water flow direction, connectivity, and attributes, helping users understand how water moves and interacts within the landscape. It serves as a foundational tool for water management, planning, and conservation efforts nationwide.