Find NHD Waterbodies & Areal Water Features
hydro_find_waterbodiesFind lakes, ponds, reservoirs, swamps, and areal water features intersecting a point, parcel, or bounding box using USGS National Map NHDPlus HR data.
Instructions
Find NHD waterbodies (lakes, ponds, reservoirs, swamps) and areal water features.
Queries NHDWaterbody (layer 9) and/or NHDArea (layer 8) polygons intersecting the geometry. Both carry gnis_name, ftype/fcode, areasqkm, and elevation.
Use when: "Is there a lake within this parcel?", "What reservoirs intersect this bounding box?", "Name the waterbody at this point."
Returns: { "finding": str, "waterbody": {count, truncated, features, provenance}, # if requested "area": {count, truncated, features, provenance}, # if requested "query_geometry": {"type": str, "crs_epsg": int} }
ftype/fcode are integer codes; ftype_label/fcode_label give readable names.
Error responses:
"Error: supply either lat+lon or geometry, not both (or neither)"
"Error: unsupported geometry type ..."
"Error: NHDPlus HR request failed: ..."
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| lat | No | Latitude in decimal degrees (WGS84). Use with 'lon'. Omit when supplying 'geometry'. | |
| lon | No | Longitude in decimal degrees (WGS84). Use with 'lat'. Omit when supplying 'geometry'. | |
| geometry | No | GeoJSON geometry object as a JSON string. Supported types: Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, or BoundingBox shorthand {"type": "BoundingBox", "bbox": [minLon, minLat, maxLon, maxLat]}. All coordinates must be WGS84 decimal degrees. Supply either this OR lat+lon, not both. | |
| feature_class | No | Which polygon layer(s) to query: 'waterbody' (lakes/ponds/reservoirs/swamps), 'area' (wide rivers/bays/rapids/dams), or 'both'. Default 'both'. | both |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||