Description: The last update to this data was completed on 6/22/2020, this update focused on reviewing existing waterbodies and folding in missing waterbodies for the Chemung HUC (02050105) and the Tioga HUC (02050104). A History of edits is listed below. The full statewide dataset can be downloaded from: http://prd-tnm.s3-website-us-west-2.amazonaws.com/?prefix=StagedProducts/Hydrography/NHD/State/HighResolution/GDB
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This web service is a subset for New York State of the National Hydrography Dataset (NHD), there is more information about each layer in the description of the groups and specific layers. The NHD is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. NHD data was originally developed at 1:100,000-scale and exists at that scale for the whole country. This high-resolution NHD, generally developed at 1:24,000/1:12,000 scale, adds detail to the original 1:100,000-scale NHD. Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes and the Atlantic Ocean. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee.
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History of edits
02/18/2020 -- Waterbody Updates to Southern Long Island HUC (02030202) & Owego-Wappasening HUC (02050103)
10/04/2019 – Waterbody Updates to Upper Susquehanna HUC (02050101)
08/19/2019 – Waterbody Updates to Chenango HUC (02050102) & Northern Long Island HUC (02030201)
Description: The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" “Standard” (http://pubs.usgs.gov/tm/11/a3/). Watershed boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative boundaries or special projects, nor particular program or agency. This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. Some areas may also include additional subdivisions representing the 14- and 16-digit hydrologic unit (HU). At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, 1:25,000-scale in Hawaii, Pacific basin and the Caribbean, and 1:63,360-scale in Alaska, meeting the National Map Accuracy Standards (NMAS). Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications.
Description: Hydrography Area contains many additional water-polygon features to Hydrography Waterbody. One of the more important is the stream/river feature. It represents the areal extent of the water in a wide stream/river with a basic set of attributes. These polygons typically encompass Hydrography Flowline artificial paths that represent the stream network. Artificial path carries the critical attributes of the stream/river, whereas Hydrography Area represents the geometric extent.
Description: Labels for polygon river features. These labels are from an invisble line file, based on Flowline's Artificial Paths that intersect Hydrography Area. Labels for the largest rivers in New York turn on at 1:577,791, while the rest of the labels for Hydrography Area turn on at 1:72,224.
Description: Waterbodies such as lake/pond features are represented in Hydrography Waterbody. They portray the spatial geometry and the attributes of the feature. These water polygons may have Hydrography Flowline artificial paths drawn through them to allow the representation of water flow direction. Other Hydrography Waterbody features are swamp/marsh, reservoir, playa, estuary, and ice mass. Some NHD Waterbody F Codes that are swamp, or reservoir are not displayed - specifically the following: 43608; 43609; 43610; 43612; 43621; 43624; 46600; and 46601
Description: This layer consists of intermittent features (features that may reoccur at irregular intervals), including the F codes 39001, 39005, and 39006. The features are: Intermittent; Intermittent, High Water Elevation; and Intermittent, Date of Photography. See group for more details, this layer turns on below 1:144,449
Description: Hydrography Flowline is the fundamental flow network consisting predominantly of stream/river and artificial path vector features. It represents the spatial geometry, carries the attributes, and contains linear referencing measures for locating features or “events” on the network. Additional Hydrography Flowline features are canal/ditch, pipeline, connector, underground conduit, and coastline. This layer turns on at 1:144,449. This layer does not display the following flowline categories: Artificial Path, Canal Ditch, and Pipeline.