Water near a point
water_nearRead-onlyIdempotent
Check water proximity for any point: returns distance to rivers, canals, lakes, oceans, and detects if the point is inside a water polygon. Filter by subtype, class, and search radius.
Instructions
Water near a point, nearest first: waterfront check, distance to river/canal/lake.
From Overture's base theme (issue #200), type=water — oceans, bays,
lakes, ponds, reservoirs, rivers, streams, canals, springs, pools.
Returns {"center", "radius_m", "in_range_count", "results": [{"name"
(when named), "subtype", "class", "distance_m", "is_salt"/
"is_intermittent" (only when true)}, ...]}, plus "truncated": true and
a "note" when more matched than were returned. No raw geometry.
distance_m is to the closest point on the feature, not its centroid —
a canal bank you are standing on reads ~0 m. Water gets dense (an
Amsterdam canal district puts hundreds of rows in a 500 m circle),
which is what in_range_count and the filters are for:
subtype/water_class match Overture's `subtype`/`class` columns
(case-insensitive substring; water_class is `class` under a
non-reserved name) — e.g. subtype="canal", subtype="river",
water_class="lake".
"on_water": true plus "water_body" means the point is *inside* a water
polygon — a lake, a reservoir, a river. For oceans and seas that is a
coarse signal: Overture cuts them into 1-degree tiles whose landward
edge covers dry coastal land, so a waterfront building reads as inside
the ocean. Those bodies are reported this way rather than as a bogus
0 m "nearest water" row, and no distance-to-coast is derived from them
(their tile boundaries include phantom cuts through open water), which
also means subtype="ocean" cannot return distance rows. Lakes and
rivers carry none of that: however large, they appear in results with
a real edge distance. The "note" says which case applies.
An empty results list is a valid answer: coverage is OSM-derived, and
"no water within 500 m" is a real finding about an arid or unmapped
place. radius_m echoes the effective radius (large values are
clamped). Returns a structured {"error": ...} if upstream is
unavailable or the dataset is missing geometry/bbox, and {"error":
"bad_request"} for a bad coordinate.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| lat | Yes | ||
| lon | Yes | ||
| limit | No | ||
| subtype | No | ||
| radius_m | No | ||
| water_class | No |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||