How water levels are measured
River Levels shows recent readings from Office of Public Works (OPW) measuring stations across Ireland.
What a water-level reading means
A measuring station records the height of the water against a reference point used at that station. The page shows the reading in metres and the time it was recorded.
Reference points can be different at different stations. A reading of 1 metre at one station cannot be directly compared with 1 metre at another station.
Readings are provisional. They may be delayed, missing or revised by the Office of Public Works.
How the estimated trend works
Where enough recent readings are available, River Levels estimates whether the water level is rising, falling or showing little change.
The estimate uses between 3 and 5 of the most recent readings shown, covering at least 30 minutes and no more than 6 hours. It is left out when the readings are too far apart or do not show a clear pattern.
An estimated trend is not a forecast
It describes the recent readings at one station. It does not predict flooding, show where flooding may happen or provide an all-clear.
The 7-day chart
The chart joins recorded readings with one solid green line. A gap is left where a value cannot be shown or readings are too far apart.
The vertical scale includes extra space so small changes do not look more dramatic than they are. The chart moves forward as newer readings arrive.
The CSV download contains the exact readings and recorded times used for the public chart.
Past high water levels
Some station pages show recorded highs, an OPW statistical flood reference or annual high water levels. These provide historical context at that measuring station.
They do not show the level at which nearby flooding starts. Historical flooding may not happen again at the same level because rivers, drainage, flood defences and the surrounding area can change.
Where the OPW marks a historical reading as unchecked, River Levels labels it clearly. Stations without enough usable historical information do not show an annual-high section.
What station readings do not show
- They do not show the area that may flood.
- They do not show the area covered by a weather warning.
- They do not predict what will happen at a property.
- They are not emergency alerts or an all-clear.
River Levels does not set a normal range or flood level for a station unless an authoritative Irish source and the relationship to that exact gauge have been reviewed. No such range or flood level is currently shown.
Source and licence
Current and historical station readings come from OPW Hydro-Data. The OPW open data used by this service is licensed under Creative Commons Attribution 4.0.
Weather warnings and advisories are issued separately by Met Éireann. A water-level reading cannot create, change or cancel a warning.