Braided

Safety and data

Safety and data · updated 16 September 2026

Braided is a good way to decide where to look. It is not a way to decide that a place is safe.

What this is

Braided takes no measurements of its own. Everything here was collected by someone else — councils, LAWA, DOC, GeoNet, LINZ, Fire and Emergency, MetService's public warnings feed, NOAA and open global models — and published for anyone to use. We gather it on a schedule, rank it against each site's own record, and put it on a map.

We do not check whether a reading is right: a gauge can be blocked, drifting, frozen, or repeating the last value it managed before it went quiet, and none of that is visible to us. The agencies whose data this is have not reviewed this app, do not endorse it, and are not responsible for anything it says.

A gauge measures one point

A river gauge measures the water at the gauge — not the ford three kilometres upstream, the side creek below it, or the crossing on the tributary. Those can be higher, faster and colder, and can change in minutes. Rain in the headwaters reaches you before it reaches the gauge, and the gauge before your phone: a falling river on this map can be a rising river in front of you.

Most gauges measure height, not flow. Where a card shows cubic metres a second, the council derived it from the height using a rating curve fitted to hand-taken measurements. The curve moves when the bed does, and above the highest flow ever measured there it is extrapolation — so the flow is least certain exactly when it matters most. Some gauges are never rated and show only a height.

Look at the water. If you are in doubt about a crossing, stay out of it.

Every reading here has already travelled

From the gauge to the council, to us, to your phone — and, on a downloaded region, from your phone's own storage. The time under each number is when it was measured, never when you are reading it, and where that gap is large the app says so and drains the colour out of the reading.

Coverage is uneven and we do not pretend otherwise. Several councils publish nothing we can use, so some of the country's largest rivers have no gauge here at all. An empty stretch of map means we have no data, not that there is nothing to worry about.

Predictions are not measurements

Tides are LINZ predictions for a standard port, above chart datum. Wind and pressure move both the height and the time, and a storm surge moves them a lot. Not for navigation — a vessel needs the official tables and charts.

The forecast on a card is an open global weather model, not a New Zealand forecaster looking at New Zealand terrain. In the mountains it will be wrong more often than MetService is. Treat it as the shape of the weather, not the weather.

Where Braided carries somebody else's hazard product — the fire season from Fire and Emergency, severe weather warnings from MetService's own feed — it repeats their words and links to them, and theirs is the version that counts. Avalanche, tsunami and civil defence it does not carry at all, only links. Follow the link before you rely on it.

Alerts are a convenience, not a safety line

A river alert fires when a reading we have received crosses a threshold. It can be late and it can never arrive: the gauge reports on its own schedule, our collection runs on ours, and delivery depends on Apple, Google, the network and your phone being on and in coverage. None of that is under our control.

No alert has ever meant a river is safe to cross. It means a number moved.

Who to ask instead

In an emergency, call 111.

Tell someone where you are going and when you expect to be back. Carry a distress beacon in the backcountry.

The legal part, briefly

Braided is free, non-commercial and provided as it is, with no warranty of any kind. We do not promise that the data is accurate, complete, current or available, that the app will work, or that a notification will arrive.

What you do with what you read here is your decision. To the fullest extent the law allows, neither Braided nor the agencies whose data it shows accept liability for any loss or damage arising from use of the app or anything in it. Nothing in this affects your rights under New Zealand consumer law, or limits any liability that cannot lawfully be limited.

New Zealand law applies. Braided is built and run by one person in Aotearoa New Zealand.