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Interested in finding a good river to float down this hot summer? Or a favorite fishing hole? Ever wonder where those blue lines mapping the rivers, streams and lakes on the US Topo and other maps come from?
US Topo 7.5-Minute Series, Ferry Swale Quadrangle covering Horseshoe Bend near Page Arizona on the Colorado River.(Public domain.)
Digital hydrography mapping provided by the USGS, such as the National Hydrography Dataset (NHD), Watershed Boundary Dataset (WBD), and new NHDPlus High Resolution (NHDPlus HR), are a valuable resource to monitoring water quality and availability, agriculture, flood risk management, environmental health, and infrastructure and development, among many others. These datasets are highly collaborative and were built cooperatively by federal, state, and local governments, as well as other organizations.
The high resolution NHD, at 1:24,000 scale or better, is the most up-to-date and detailed hydrography dataset for the United States. As a part of The National Map, it represents the Nation’s inland water drainage network including rivers, streams, canals, lakes, glaciers, and more. The WBD is the seamless baseline drainage area framework for the Nation, delineated into a nested multi-level, hierarchical drainage system.
These datasets are more than just maps – their underlying databases contain key attribute information that add intelligence to the mapped data. For example, the NHD contains flow direction that enables users to understand upstream and downstream relationships within the stream network.
Together, the NHD and WBD, along with data from the 3D Elevation Program (3DEP), are being used to create the new NHDPlus High Resolution, a dataset which includes stream reaches, elevation-based catchment areas, flow surfaces, and value-added attributes that enhance stream network navigation, analysis, and data display.
When completed for the entire Nation, the NHDPlus HR will provide a single, scalable hydrography framework that is open and accessible for use by everyone, including government, citizens, and industry. The NHDPlus HR supports a limitless range of applications, such as estimating when and where a toxic spill will affect downstream populations, ecosystems, and drinking water intakes, or enabling property owners to better understand water availability.
The NHDPlus HR framework is key to bringing flood forecasting down to the street level in the National Water Model. In the StreamStats Program, NHDPlus HR can help to provide more accurate streamflow statistics such as peak flows for bridge or culvert engineering designs and low flows for studies of biological resources in times of drought. Similarly, it can be used by the National Water-Quality Assessment (NAWQA) to better understand the Nation’s water quality.
Check out these data on the downloadable US Topo maps, download datasests or add map services to web maps, or explore them on The National Map Viewer!
