{"id":"ireland-water-levels","slug":"ireland-water-levels","name":"Ireland Water Level Dataset","description":"Daily mean water level against Ordnance Datum for the Irish national hydrometric network: 450 stations coordinated by the Office of Public Works, accumulated from a publisher that serves a five-week window.","methodology":"Collected from the waterlevel.ie GeoJSON index and per-sensor CSV under CC BY 4.0. Fifteen-minute readings are reduced to daily means, and a day with fewer than 72 of its expected 96 readings is refused rather than averaged from a partial day. Each sensor’s parameter is confirmed against the publisher’s own station page before any value is read: the interface identifies a series only by a code, and the codes are not self-explanatory — one returns values that read perfectly as a water temperature and are the station’s battery voltage. Levels are taken against Ordnance Datum rather than the staff-gauge reading the same stations also publish, because Ordnance Datum is national and staff-gauge zeros are local.","domains":["river-flow"],"metricIds":["river-level"],"subjectScope":"Irish hydrometric stations reporting against Ordnance Datum","cadence":"daily","version":"1.0.0","released":"2026-08-26","changelog":[{"version":"1.0.0","date":"2026-08-26","summary":"First release. Ireland becomes a monitored jurisdiction.","additions":["Daily mean water level for 450 stations against Ordnance Datum."]}],"limitations":["This is not a historical archive. The Office of Public Works serves roughly five weeks per station through this interface; its longer record sits on a separate Kisters application whose machine interface Hydrionis has not located and does not scrape. The record here deepens with each collection rather than reaching backwards, and the earliest date held is close to the date Hydrionis first read the service.","A level is not a depth of water. It states where the surface sits relative to Ordnance Datum, which is a national levelling reference, not the river bed.","The publisher does not say which river a station sits on through this interface, so no Irish station is linked to a water body. They appear in the monitoring network and not on any river profile.","Discharge is not available here. The site refers to flow records on its historical service, which is the same access limit as the depth."],"observationCount":30857,"seriesCount":451,"subjectCount":451,"from":2025,"to":2026,"sourceIds":["ie-opw-waterlevel"],"units":["m"],"redistributable":true,"commerciallyReusable":true,"citation":"Hydrionis (2026), Ireland Water Level Dataset, version 1.0.0. Retrieved from https://hydrionis.com/data/datasets/ireland-water-levels/","downloads":[{"file":"/downloads/observations-river-flow-ie-opw-waterlevel.csv","format":"CSV","label":"river-flow observations from OPW waterlevel.ie (31,104 rows)"}],"apiPath":"/api/v1/datasets/ireland-water-levels.json","lastFetched":"2026-10-01","fields":[{"id":"river-level","name":"River level","definition":"Height of the water surface at a gauging station, measured against that station’s own zero point.","unit":"m","nativeGeography":["river-gauge"],"comparabilityNotes":"Level is measured against each station’s own zero point, which is set locally and is not a common datum. Two gauges reading 3 m are not at the same height, and a level is not a depth of water: it says where the surface sits relative to a reference, not how deep the river is. Read a level against that gauge’s own record, never against another gauge’s."}]}