Flooding level chart card with background

Who it’s for

City operators and hydrologists monitoring rivers or drainage networks ask “is the water level rising or falling?” They combine trend data with a recognizable background for dedicated situation rooms or public-facing displays.

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, displayed over the preset background image.

• 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
• Decorative background image bundled with the widget, with a white overlay that keeps the text readable
• 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 swap the background image — open the widget settings and set Background to a different image or switch to a solid color.
• To adjust how much the background shows through — change the Overlay opacity; lower values reveal more of the image, higher values push it further back.
• 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 hide the entity name subtitle or the timestamp — turn off Show subtitle or Show date.

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.
• If the background image reduces contrast, raise the Overlay opacity to keep the text readable from a distance.