Flooding level chart card

Who it’s for

City operators and hydrologists monitoring rivers or drainage networks ask “is the water level rising or falling, and how does it compare to the previous period?” A single reading does not say whether a flood risk is building or receding; the trend does.

What it does

A sensor averaging 0.8 m this week, up from 0.5 m last week, shows a +60% delta in red — the level is rising. The chart below confirms the upward trend over the selected period.

• Large current water level in the center, color-coded across three severity levels from Normal to Critical
• Percentage change vs. the previous period, with a colored arrow — red when the level is rising (worse), green when falling (safer)
• Absolute water level change in meters shown below the delta percentage
• Time-series chart of water level readings over the selected time window, averaged per interval
• Shows one sensor’s data; it does not compare multiple locations

How to set up

Data keys

Key	Role	Type	Description
flooding	Chart series	Timeseries	Water level in meters; drives the chart. The Latest, Delta percent, and Delta absolute overlays are automatically derived from this same key
Latest	Latest value	Timeseries	The headline figure above the chart. Its own color ranges are where the band colors are edited
Delta percent	Percentage change	Timeseries	Change against the previous period, as a percentage
Delta absolute	Absolute change	Timeseries	Change against the previous period, in the key’s own unit

The widget ships with a simulated function datasource key labeled Flooding level, so it draws random values until you point the datasource at a device and rename the key.

To point it at your own device: open the dashboard in edit mode, open the widget’s Datasources, pick the entity or entity alias, and replace the function key with the key your device reports.

If the key has never reported for the selected time window, the chart is empty and all overlays show no data.

Value ranges

Range (m)	Level	Color
0–1	Normal	Blue
1–3	Warning	Orange
3+	Critical	Red

How to customize

• To use your own flood thresholds — edit the color ranges on the Latest data key; adjust the three default levels to match your local alert levels.
• To change the unit label — set Units to your preferred label (e.g. ft for feet).
• To hide or show the chart — toggle Show chart in the widget settings.
• To change the chart line color — set Chart color.
• To show min, max, or total in the legend instead of avg — edit the Legend settings.
• To hide the entity name subtitle or the timestamp — turn off Show subtitle or Show date.
• To match your dashboard’s fonts — set the font options under each data key’s appearance settings.

Tips

• A rising delta means the flood risk is increasing. The arrow turns red when the level rises vs. the previous period and green when it falls.
• Pair this card with a flood alert rule to get notified when a rising trend reaches the Warning threshold before it becomes Critical.