The mapped representation of surface waters including streams, rivers, lakes, and other water features, from the the U.S. National Hydrography Dataset (NHD), and the Canada National Hydrographic Network (NHN).
A topographically defined area of land with surface runoff that drains to a common outlet or outlets (the SSDA/FDA and WBD/HUC8).
International Watersheds Initiative (IWI):
Incepted in 1997, the International Watersheds Initiative (IWI) is an approach to resolving transboundary water issues grounded on the belief that local communities, given appropriate assistance, are best placed to achieve solutions. This approach operates on an ecosystem focus, recognizing that ecosystems function as whole entities and should be managed as such, rather than being bound by traditional political boundaries.
Transboundary watersheds along the Canada – United States International Boundary that define the hydrographic data harmonization project area.
National Hydrographic Network (NHN):
Geospatial digital dataset that represents the water drainage network of Canada with features such as streams, rivers, lakes, etc.
National Hydrography Dataset (NHD):
Geospatial digital dataset that represents the water drainage network of the United States with features such as streams, rivers, lakes, etc.
Hydrologic Unit (HU):
A single HU represents all or some portion of the extent of surface water drainage to a selected stream outlet. A system of HU is organized in a nested, hierarchical system which creates a baseline drainage area framework that can be used for the analysis and reporting of water resource information. The selection and delineation of drainage area boundaries are based on hydrologic principles.
Sub-sub Drainage Areas (SSDA) and Fundamental Drainage Areas (FDA):
Canada’s geospatial digital dataset containing information about the country’s drainage areas in four hierarchically nested levels. The SSDA and FDA provide the geometry and attribution for HUs within Canada.
Watershed Boundary Dataset (WBD):
The United States’ geospatial digital dataset containing information about drainage areas in eight nested levels. The WBD provides the geometry and attribution for HUs within the United States.