← The record · All reference data

wbd/ — USGS Watershed Boundary Dataset (HUC boundaries)

Authoritative Hydrologic Unit (HU) polygon boundaries framing the data-center campus AOI, pulled from the USGS National Map Watershed Boundary Dataset (WBD) ArcGIS REST service. These are the source geometry the bundle’s watershed GeoJSON feed (issue #61) is assembled from, for the watershed map (#72).

Source

• USGS National Map WBD — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer (the seamless national WBD; HU-level sublayers keyed by digit count: layer 6 = 12-digit Subwatershed, layer 5 = 10-digit Watershed, layer 4 = 8-digit Subbasin).

• Pulled by the watermark.hydrology.connectors.wbd connector; regenerable with:

  watermark wbd --write              # the campus AOI's HU12 + HU10, default
  watermark wbd --levels 12,10,8 --write   # add the coarser HU8 Subbasin too
  watermark wbd --point -84.1234,40.7969 --write   # any WGS84 point

  The AOI defaults to the data-center-campus tracking-site POI’s bbox centroid (data/entities/poi/data-center-campus.md); the connector selects the HU containing that point at each level. Raw responses cache under the git-ignored data/cache/hydrology/wbd/; the committed fixture for the offline test lives at tests/fixtures/hydrology/wbd/.

Files

Each file is a one-feature GeoJSON FeatureCollection; the HU attributes (huc, name, area_sqkm, to_huc, …) ride on the feature properties, with full provenance in the top-level meta.

Scope / gaps

• The campus sits in the Pike Run subwatershed (HU12) of the Middle Ottawa River watershed (HU10). The hydrologic lineage continues outward — Ottawa River → Auglaize subbasin (HU8 04100007) → Maumee subregion (HU4 0410) → Lake Erie. The coarser Subbasin/basin polygons are not committed here: a ~1 MB Subbasin outline adds little to a campus-scale map. Pull them on demand with --levels 12,10,8 (or query the WBD service directly) if needed.
• Geometry is verbatim from the WBD (WGS84 / EPSG:4326), display-only — never reprojected or simplified. The names (“Pike Run”, “Middle Ottawa River”) are the USGS WBD names; the project’s informal “Lost Creek / Maumee watershed” framing maps to this real HU nesting.