Tidewater: project overview

Tidewater syncs tide-gauge readings from coastal sensors into one queryable store, so the harbor team can plan around the water instead of guessing. It replaces the old nightly cron scripts.

Goals

Ingest readings within 60 seconds of capture
Keep 10 years of history at 1-minute resolution — about 5 million rows per gauge
Expose a small HTTP API (GET /readings?gauge=ID&from=ISO)
Alert when two neighboring gauges disagree by more than 15 cm for ten minutes in a row, which usually means a stuck float rather than a real surge

Heads up: gauge T-07 reports in feet. Conversion happens at ingest, not at query time.

Status

Area	State	Owner
Ingest pipeline	Done	Ana
Query API	In review	Ben
Alerting	Not started	unassigned

Design

Waves diagram — Sensors feed a queue; workers write to the store.

Each worker runs a loop like this:

for reading in queue.drain():
    row = convert(reading)      # feet -> meters happens here
    if row.valid:
        store.insert(row)
    else:
        log.warn("bad reading", reading.id)

See the runbook for deployment, or the missing page to check how 404s look.