{ "downloaded_on": "2026-11-06", "coordinate_system": "EPSG:4326", "analysis_projection": "EPSG:32119 (metres)", "outputs": [ { "path": "basins.full.geojson", "features": 17, "bytes": 3794407, "sha256": "fd4a0a46111e1b2e63f6da1afb49b460fa470d824651f779ce09bc7d714fcebd", "simplification_metres": 0 }, { "path": "basins.geojson", "features": 17, "bytes": 332074, "sha256": "966a22f05b81caff1cfb7231ca198b2b4d80e89d42ee54cd6d247e6e581c1d5b", "simplification_metres": 50 }, { "path": "major-rivers.full.geojson", "features": 43, "bytes": 959822, "sha256": "5a2dbdbc88ee8238e6f515802f9bc462ef64767b6873e96a951fc19baf7cd29a", "simplification_metres": 0 }, { "path": "major-rivers.geojson", "features": 43, "bytes": 259169, "sha256": "95d27315dbe490a09e02e59efdd822d5585c73d701f46ea067d22c6f15ae23a9", "simplification_metres": 50 }, { "path": "major-waterbodies.full.geojson", "features": 125, "bytes": 2032727, "sha256": "150d7a91f76e88b19e45e5f66af84e68a19039002cdb20555f30d61d5c70aa2d", "simplification_metres": 0 }, { "path": "major-waterbodies.geojson", "features": 125, "bytes": 476794, "sha256": "f21d2f45722e14ebb7ddd7d4a537ab6325b6b18a4bddec51f7db47ddea8fc710", "simplification_metres": 50 } ], "sources": [ { "id": "basins", "url": "https://maps.deq.nc.gov/arcgis/rest/services/DEQ/NC_RiverBasins/MapServer/0", "downloaded_on": "2026-11-06", "query_file": "basins-queries.json", "source_count": 18, "raw_sha256": "b0272f2c7d1c7f8e4f750107c5ef12888f66d9600325851c8416905a66889714", "layer_name": "River Basins", "source_spatial_reference": { "wkid": 102100, "latestWkid": 3857, "xyTolerance": 0.001, "zTolerance": 2, "mTolerance": 2, "falseX": -20037700, "falseY": -30241100, "xyUnits": 10000, "falseZ": 0, "zUnits": 1, "falseM": 0, "mUnits": 1 }, "display_min_scale": 0, "display_max_scale": 500000, "description": "", "copyright": "" }, { "id": "flowlines", "url": "https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/4", "downloaded_on": "2026-11-06", "query_file": "flowlines-queries.json", "source_count": 4660, "raw_sha256": "8433fa0afbe776eb3691af96c64c56b8c9f429b8f045320a0a57a5de711c2b4a", "layer_name": "Flowline - Small Scale", "source_spatial_reference": { "wkid": 102100, "latestWkid": 3857, "xyTolerance": 0.001, "zTolerance": 0.001, "mTolerance": 0.001, "falseX": -21950421.053211346, "falseY": -30241100, "xyUnits": 144357891.6793486, "falseZ": -100000, "zUnits": 10000, "falseM": -100000, "mUnits": 10000 }, "display_min_scale": 577790.554289, "display_max_scale": 73221, "description": "Abstract:\nThe National Hydrography Dataset (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. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) 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, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee. Use the metadata link, http://nhdgeo.usgs.gov/metadata/nhd_high.htm, for additional information.\nPurpose:\nThe NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all.", "copyright": "U.S. Geological Survey" }, { "id": "waterareas", "url": "https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/7", "downloaded_on": "2026-11-06", "query_file": "waterareas-queries.json", "source_count": 147, "raw_sha256": "1f61a84a6dd28fbb9e92b3570b1a3d789ba68dbba84790e1902d8e8de0d6530c", "layer_name": "Area - Small Scale", "source_spatial_reference": { "wkid": 102100, "latestWkid": 3857, "xyTolerance": 0.001, "zTolerance": 0.001, "mTolerance": 0.001, "falseX": -21950421.053211346, "falseY": -30241100, "xyUnits": 144357891.6793486, "falseZ": -100000, "zUnits": 10000, "falseM": -100000, "mUnits": 10000 }, "display_min_scale": 577790.554289, "display_max_scale": 73221, "description": "Abstract:\nThe National Hydrography Dataset (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. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) 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, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee. Use the metadata link, http://nhdgeo.usgs.gov/metadata/nhd_high.htm, for additional information.\nPurpose:\nThe NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all.", "copyright": "U.S. Geological Survey" }, { "id": "waterbodies", "url": "https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/10", "downloaded_on": "2026-11-06", "query_file": "waterbodies-queries.json", "source_count": 1139, "raw_sha256": "e89ccfa7cc1b5389b2cd6b19d89b02c728884055b5a35641adf70a556b92f536", "layer_name": "Waterbody - Small Scale", "source_spatial_reference": { "wkid": 102100, "latestWkid": 3857, "xyTolerance": 0.001, "zTolerance": 0.001, "mTolerance": 0.001, "falseX": -21950421.053211346, "falseY": -30241100, "xyUnits": 144357891.6793486, "falseZ": -100000, "zUnits": 10000, "falseM": -100000, "mUnits": 10000 }, "display_min_scale": 577790.554289, "display_max_scale": 73221, "description": "Abstract:\nThe National Hydrography Dataset (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. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) 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, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee. Use the metadata link, http://nhdgeo.usgs.gov/metadata/nhd_high.htm, for additional information.\nPurpose:\nThe NHD is a national framework for assigning reach addresses to water-related entities, such as industrial discharges, drinking water supplies, fish habitat areas, wild and scenic rivers. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network, much like addresses on streets. Once linked to the NHD by their reach addresses, the upstream/downstream relationships of these water-related entities--and any associated information about them--can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS). GIS can also be used to combine NHD-based network analysis with other data layers, such as soils, land use and population, to help understand and display their respective effects upon one another. Furthermore, because the NHD provides a nationally consistent framework for addressing and analysis, water-related information linked to reach addresses by one organization (national, state, local) can be shared with other organizations and easily integrated into many different types of applications to the benefit of all.", "copyright": "U.S. Geological Survey" } ], "selection": { "river_names_requested": [ "Broad River", "Cape Fear River", "Northeast Cape Fear River", "Catawba River", "Chowan River", "French Broad River", "Hiwassee River", "Little Tennessee River", "Lumber River", "Neuse River", "New River", "Pasquotank River", "Roanoke River", "Savannah River", "Tar River", "Pamlico River", "Watauga River", "White Oak River", "Yadkin River", "Pee Dee River", "Deep River", "Haw River", "Eno River", "Dan River", "South Yadkin River", "South Fork Catawba River", "Tuckasegee River", "Nolichucky River", "Pigeon River", "Waccamaw River", "Nottoway River", "Meherrin River", "Cashie River", "Perquimans River", "Alligator River", "Pungo River", "North River", "Lockwoods Folly River", "Shallotte River", "Scuppernong River", "Trent River", "Newport River" ], "river_names_present": [ "Alligator River", "Broad River", "Cape Fear River", "Cashie River", "Catawba River", "Chowan River", "Dan River", "Deep River", "Eno River", "French Broad River", "Haw River", "Hiwassee River", "Little Tennessee River", "Lockwoods Folly River", "Lumber River", "Meherrin River", "Neuse River", "New River", "Newport River", "Nolichucky River", "North River", "Northeast Cape Fear River", "Pamlico River", "Pasquotank River", "Pee Dee River", "Perquimans River", "Pigeon River", "Pungo River", "Roanoke River", "Scuppernong River", "Shallotte River", "South Fork Catawba River", "South Yadkin River", "Tar River", "Trent River", "Tuckasegee River", "Waccamaw River", "Watauga River", "White Oak River", "Yadkin River" ], "river_names_absent_after_clip": [ "Nottoway River", "Savannah River" ], "water_filter": "Named water features from NHD layers 7 and 10 with source area >= 1 km2, intersected with the union of NCDEQ basin polygons; discard clipped remnants under 0.01 km2. Empty/space-only names excluded.", "clip": "Union of NCDEQ river basin polygons; exploratory geographic extent, not an official election jurisdiction boundary." }, "vintage": { "NCDEQ": "Layer metadata does not state source compilation date; downloaded 2026-11-06. Do not call it a 2026 survey.", "USGS_NHD": "Map service copyright text says Data Refreshed October, 2026; individual segments have their own FDATE in raw files. Small Scale service rendering range is approximately 1:577,791 to 1:73,221, not a guaranteed positional accuracy. NHD metadata describes source scales generally 1:100,000 or 1:24,000/1:12,000 depending on resolution." }, "methodology": [ "18 basin source polygons dissolved to 17 named basins (Savannah has two parts).", "Requested 42 named major/main rivers and tributaries; 40 names intersect the NC basin extent. Not every stream in NC is included. Dissolved segment lines by name plus GNIS ID, preserving different rivers with the same name and retaining disjoint segments.", "Full files are unsimplified after clipping and dissolve, rounded to six decimal degree places. Display files use 50 metre Douglas-Peucker topology-preserving simplification in NC State Plane metres, then WGS84 and six decimal places.", "River centerlines support exploratory crossing/boundary preference scores; they do not encode bridge or ferry access, riverbank widths, passability, or legal district contiguity.", "Basin boundaries divide drainage catchments; keeping a basin together and following a river as a district boundary are different objectives.", "Any precinct-edge geographic score should be labeled a proxy, computed against full geometry with an explicit distance tolerance. Do not remove contiguity edges solely because a river is present." ], "source_pages": [ "https://www.deq.nc.gov/about/divisions/water-resources/water-planning/basin-planning/basin-planning-branch-maps", "https://maps.deq.nc.gov/arcgis/rest/services/DEQ/NC_RiverBasins/MapServer", "https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer" ], "license_notes": "USGS NHD service states data are open and non-proprietary with no use constraints, requests acknowledgment, and cautions against site-specific regulatory use. NCDEQ layer exposes no specific copyright text; retain NCDEQ attribution." }