New Hydro Map Service Available
The U.S. Geological Survey releases a new tile cached map service for hydrography
The new “USGS Hydrography - Cached” overlay service is designed to act as a fast “overlay”, displaying hydrography in the familiar USGS topo map symbology, for display on top of basemaps, satellite imagery, or other map services. Because it is cached, the service should perform well at many different scales. This new cache supports visualization zooming down to 1:9,000 scale (Level 17 in Google Maps tile levels). The service is available as both an ESRI REST service enabling its use in ArcGIS desktop, ArcGIS Online, and as a Web Map Tile Service for inclusion into many other interactive mapping applications.
The USGS Hydrography - Cached overlay is built from The National Hydrography Dataset (NHD). The NHD is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams).
The previous Hydrography basemap, “USGS Hydro NHD”, incorporated shaded relief as part of the map, and thus, could not be used as a map overlay. This older Hydrography basemap service is planned for decommissioning in the near future (April-May 2017) when a new updated shaded relief (a.k.a hill shade basemap) will be published. A similar view to the planned retired basemap can be created using the Hydrography - Cached service overlain on top of the new, to be published, shaded relief basemap. Note also that the new cached map does not include the Watershed Boundaries Dataset, but will continue to be available in the dynamic NHD web service, and can be added as a separate layer if desired.
More details and the full list of web based map services available from The National Map services webpage.