Set thresholds and threshold emails

Commercial · admin or editor

A threshold line is a named flow or level for one gauge, such as “Flood Watch” or “Low water”. It applies to that gauge everywhere in your organisation: charts, tiles, the map, report tables and emails.

In an area, open the Thresholds tab and pick the Gauge and the Variable (flow, level or inflow).
Press Add line and give it a Name. The name is what charts, tables and reports print.
Pick a Direction: Upper (reached at or above), Lower (reached at or below), or Reference (drawn only, no status or email).
Enter the value. Levels are metres above the gauge datum; you can record the datum and a source and notes with the line.
Tick Show on graph, and Email when an observed reading crosses it and/or Email when the forecast crosses it to email your organisation's members.
Press Add line. A preview chart shows the line against the gauge's record.

The Thresholds tab for Grand River at Galt with the gauge and variable pickers, Add line, and the Low water line's fields — The Thresholds tab: pick a gauge and variable, then add or edit lines.

Threshold line cards for Low water and Flood Watch, with direction, colour and email checkboxes — Each line's direction, colour, graph and email settings.

Seasonal values and revisions

Switch Single value | Seasonal to Seasonal for a line that changes through the year. Enter dates and values, paste them from a spreadsheet or load a CSV; choose Linear or Step between points. To change a line from a date without losing its history, use Add a revision from a date.

Where to start

If you have no official values yet, the FlowAi estimate (not an official threshold) panel gives return-period flows for the gauge. Start a new line from it fills in a line you can adjust.

Who gets threshold emails: every member, unless they turn off Email me when my organisation's thresholds are crossed in Profile › Notifications. A forecast email for a level line uses the daily-mean level forecast.