NASA WaterData OGC API v0 (latest-continuous collection) — polls configured
parameter codes within an operator-set bbox and publishes on the new
CENTRAL_HYDRO stream.
- Subject: central.hydro.<parameter_code>.<agency>.<bare_site_no>
(e.g. central.hydro.00060.usgs.05420500). The agency/site decomposition
lives in a single _subject_tokens_for_id helper.
- Default parameter codes: 00060 (discharge), 00065 (gage height),
00010 (water temperature). Operator-tunable; single SoT in
_DEFAULT_PARAMETER_CODES — no parallel literals.
- Composite dedup: nwis:<monitoring_location_id>:<param>:<time_iso>.
Prefix kept in dedup key for cross-agency uniqueness.
- Pagination: follows OGC 'rel=next' link until absent (cursor-based).
- Region bbox is REQUIRED in practice; adapter logs WARN at startup if
region is None (does not refuse to start).
- New stream CENTRAL_HYDRO added to streams.py registry (one line).
Retention mirrors CENTRAL_DISASTER (7 days, 1 GiB).
- No removal pattern in v1 — sites are static; missing data is the signal.
Upstream divergences from the original spec brief, caught by pre-build curl:
- Collection is 'latest-continuous', not 'instantaneous-values'.
- Site filter param is 'monitoring_location_id' (singular), not
'monitoring_locations_id' (plural).
- Site identifier requires agency prefix in queries (USGS-NNNNN).
- feature.id is a per-record UUID, not stable; dedup uses joint key.
Ships disabled; operator enables via GUI after setting a bbox.
