Photo: Sonse · CC BY 2.0Dublin sits beside the Tolka Estuary behind the River Dodder (Tidal): 6.1% of its homes stand low
Dublin has no Hazard risk Grade: the figures it needs aren’t complete.
What stands out about Dublin’s hazards
From the EPA’s radon map, Geological Survey Ireland’s landslide map, the OPW’s flood relief schemes and our estimate of low-lying homes, below.
What Dublin faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Low-lying homes
By the coast
Radon
Landslides
Bathing water
Flood scheme
Ground heights
Dublin has no Hazard risk Grade
Each figure is placed among Irish towns as the grade would place it, without a letter.
Less sure: The low-lying figure is our estimate from ground heights and the river map, not an official flood map. It can show a town is low-lying; it can’t show a town is safe.
6.1% of Dublin’s homes stand low beside the Tolka Estuary
Low-lying homes, a TownRatings estimate from OPW and Geological Survey Ireland LiDAR ground heights and the EPA’s river map: not an official flood map.
Share of each town’s homes standing low by big water, for the towns measured in detail. 43% have none; Dublin has more than 70% of them.
Low-lying homes across County Dublin’s towns · 106 towns measured in detail
Homes: OpenStreetMap buildings of 30 m² or more, not tagged as non-residential, in the town’s Census 2022 Small Areas. Heights: GSI Open Topographic Data LiDAR (OPW, TII and GSI surveys). Water: EPA river network (rivers of Strahler order 5 or more), lakes, estuaries and coastal waters.
February 2026 brought the River Tolka’s highest day at Clonee Weir since 2021
Each winter’s highest level (October to September) at the OPW’s Clonee Weir gauge, in Dublin, since 2021, in metres above the gauge’s zero. Nine days in ten it runs between 0.14 m and 0.49 m.
- 13 February 20261.49 m
- 21 October 20231.48 m
- 6 August 20231.36 m
- 2 March 20241.34 m
- 15 November 20251.31 m
- 27 January 20261.16 m
Since 2021 the River Tolka has run above its usual top on 160 days, most of them in the winters of 2023–24 and 2022–23.
Measured by its highest day, last winter (2025–26) was the highest of the 5 on record here.
Source: OPW Hydro-Data (waterlevel.ie/hydro-data), Clonee Weir gauge (station 09112): daily maximum and mean levels, inspected and provisional data. The usual range is the 5th to 95th percentile of daily means, worked out by TownRatings. Live levels are on waterlevel.ie.
Weather and flood warnings for Dublin
Where to see the warnings in force, and what this page can’t count.
Met Éireann issues yellow, orange and red warnings for rain, wind and coastal flooding county by county; Dublin is covered by County Dublin’s.
| Warning | What Met Éireann means by it |
|---|---|
| Yellow | Weather that isn’t unusual but can be dangerous in places: be aware. |
| Orange | Infrequent, dangerous weather that can put people and property at risk: be prepared. |
| Red | Rare, extremely dangerous weather: take action to protect yourself and your property. |
Met Éireann doesn’t publish an open archive of past warnings, so how often warnings have covered Dublin can’t be counted here.
6 flood relief schemes protect parts of Dublin
The Office of Public Works’ completed flood relief schemes and the areas each one benefits (OPW open data, CC BY 4.0).
A scheme lowers the chance of flooding behind it; it doesn’t remove it. The low-lying figure counts homes behind defences too, so a defended town can still show a high share.
In County Dublin, OPW schemes protect parts of 11 other places, including Clonsilla, Sandymount, Mulhuddart, East Wall, Clontarf West.
| Town | Scheme | Designed for | Homes behind it | Away |
|---|---|---|---|---|
| Dublin Dublin | River Dodder (Tidal) | 1 in 50 | 1.9% | – |
| St Stephen's Green Dublin | South Campshires Flood Relief Scheme | 1 in 200 | 5.9% | 2.4 km |
| Grand Canal Dock Dublin | South Campshires Flood Relief Scheme | 1 in 200 | 14% | 3.0 km |
| Ballsbridge Dublin | River Dodder (Tidal) | 1 in 50 | 32% | 3.0 km |
| Ballybough Dublin | River Tolka ( Dublin) Flood Relief Scheme | 1 in 100 | 22% | 3.4 km |
| East Wall Dublin | Spencer Dock Flood Relief Scheme | 1 in 200 | 82% | 3.6 km |
0.3% of Dublin’s homes stand on landslide-prone ground
Geological Survey Ireland’s landslide susceptibility map (1:50,000), read at every home.
Homes on ground rated high or moderately high
That is a higher share than in 78% of Irish towns; the median is 0% for County Dublin’s towns and 0% for Irish towns.
GSI rates ground from low to high by its slope, soil and rock. Most Irish landslides are on steep upland slopes and peat after heavy rain; a town on flat ground has almost none.
High means the ground could slide under the right conditions, such as days of heavy rain on a steep, wet slope; it isn’t a forecast that it will.
GSI landslide susceptibility, high and moderately high classes, share of the town’s homes on mapped ground (CC BY 4.0).
An estimated 4.3% of Dublin’s homes are above the radon reference level
The EPA’s radon map: for each 10 km square, the estimated share of homes above the national reference level of 200 Bq/m³.
A square where 10% or more of homes are estimated above the reference level is a High Radon Area; 0% of Dublin’s homes are in one. The map is an estimate by area: two neighbouring houses can differ a lot.
A test is the only way to know a home’s level: two detectors, left for three months in a living room and a bedroom.
EPA radon map of Ireland (10 km grid), averaged over the town’s homes (CC BY 4.0).
115 EPA-licensed sites lie inside Dublin
Factories, farms, power plants and waste sites that hold an EPA licence for their emissions, in Dublin and around its centre.
| Site | Licence and activity | Away |
|---|---|---|
| B.G. Flexible Packaging Limited. | Industrial Emissions licence | inside |
| Diageo Ireland Unlimited Company | Industrial Emissions licence · food and drink | inside |
| Independent Newspapers Ltd. | Industrial Emissions licence | inside |
| Our Lady's Hospital for Sick Children | Industrial Emissions licence | inside |
| Mater Misericordiae University Hospital | Industrial Emissions licence · waste | inside |
| Van Leer Ireland Ltd. | Industrial Emissions licence | inside |
| Lower Oriel Street | Waste licence | inside |
| Healthbeacon Limited | Waste licence | inside |
| Activity | Sites |
|---|---|
| Not classed in the register | 38 |
| Waste | 37 |
| Energy | 21 |
| Chemicals | 16 |
| Food and drink | 5 |
| Metals | 3 |
Within 5 km: 21 under Industrial Emissions licences, 12 under older IPC licences and 7 waste facilities.
An EPA licence sets what a site may release to air, water and land; it doesn’t mark the site as an accident hazard.
Sites holding dangerous substances in bulk come under the COMAH (Seveso) rules, but the HSA’s list of them has no open licence, so upper- and lower-tier sites aren’t counted here.
Source: EPA registers of Industrial Emissions, IPC and waste licences, sites licensed on 31 October 2026; distances in a straight line from the town’s centre.
Hazards in the places around Dublin
Low-lying homes, radon and landslide ground, town by town.
| Town | Low-lying | Radon | Landslides |
|---|---|---|---|
| Dublin | 6.1% | 4.3% | 0.3% |
| The Liberties 18,460 · 0.3 km | 1.7% | 3.8% | 0% |
| Christchurch 6,778 · 0.8 km | under 0.1% | 3.8% | 0% |
| Dolphins Barn 18,799 · 0.8 km | 2.4% | 3.8% | 0% |
| Temple Bar 7,276 · 1.3 km | 27% | 3.8% | 0% |
| Portobello 5,732 · 1.5 km | 0% | 3.8% | 0% |
| Stoneybatter 18,644 · 1.7 km | 3.9% | 3.8% | 0% |
Of the places around Dublin, Temple Bar has the most homes standing low by big water (27%), 1.3 km away.
A dash under Low-lying: not measured there (too few homes with detailed ground heights), not none.
Get ready for what Dublin faces
What to do, and what to ask before you move.
- Never walk or drive through floodwater: 30 cm of moving water can float a car.
- Move valuables, papers and medicines upstairs.
- Turn off gas, electricity and water if you’re told to.
- Test over three months, in a living room and a bedroom.
- Above 200 Bq/m³, a small sump and fan usually fixes it.
- The EPA sells radon test kits at radon.ie and lists registered contractors who fix high readings.
- Bring in or tie down bins, trampolines and anything the wind can lift.
- Keep away from coastal paths and piers while an orange or red warning is in force.
- Charge phones and keep a torch: fallen lines are the commonest storm damage.
- After the storm, report a fallen line to ESB Networks and keep well clear of it.
- Ask whether the home has ever flooded, and get a buildings insurance quote before you commit: flood cover isn’t always offered.
- Behind a completed OPW scheme? Insurers in Insurance Ireland agreed in 2014 to offer flood cover in those areas: ask for it by name.
- Ask the seller or landlord for a radon test result, or test in your first months there.
- Check the address on floodinfo.ie: the OPW’s flood maps and its record of past floods.
What this data can and can’t tell you
- An estimate, not a flood map. Low-lying homes is a TownRatings modelling step: each home’s ground height from LiDAR, against the level of the nearest big river (Strahler order 5 or more), lake or estuary within 1 km, or the sea within 2 km. A home within 5 m of the water’s level, or below 4 m near the sea, counts.
- Flood counts only one way. A high share of low-lying homes lowers the Hazard risk Grade; a low share never raises it, because defences, small streams, culverts, groundwater and flash floods don’t show in ground heights. Below the national median a town scores as the median.
- Defences aren’t counted. Flood defences aren’t taken off: the OPW scheme that protects the most homes is shown instead, with its design standard.
- Measured where the heights are detailed. A town is measured, and counted, only where 80% of its homes stand on LiDAR heights. Elsewhere the page says flooding isn’t measured, never that the town is dry.
- Radon is an estimate by area. The EPA’s radon map gives the estimated share of homes above 200 Bq/m³ for each 10 km square, averaged here over the town’s homes. It says where to test, not what one house holds.
- The sea is measured by height. Homes count as low by the sea when their ground is under 4 m and within 2 km of coastal or estuary water; waves, surges and erosion aren’t modelled.
- Landslide ground is a map of where slides could start. GSI’s susceptibility map rates the ground itself; it doesn’t record past slides or say when one will happen.
- Bathing water is rated season by season. The EPA classes each identified bathing water from four seasons of samples; a rating says how clean the water has been, not how safe it is to swim.
- One town, many streets. Risk is street by street. Check a specific address on floodinfo.ie before you buy or rent.
Check any address against the OPW’s official flood maps on floodinfo.ie
Questions about flooding and hazards in Dublin
Does Dublin flood?
About 6.1% of Dublin’s homes stand low beside the Tolka Estuary: a higher share than in 70% of Irish towns. That is our estimate from ground heights, not an official flood map. For a single address, the OPW’s official flood maps and past floods are on floodinfo.ie.
Is radon a problem in Dublin?
The EPA’s map estimates that about 4.3% of homes around Dublin are above the radon reference level of 200 Bq/m³: a higher share than in 53% of Irish towns. 0% of its homes are in a High Radon Area. The only way to know a house is a three-month test.
Is Dublin at risk of landslides?
0.3% of Dublin’s homes stand on ground rated high or moderately high for landslides. Most slides happen on steep slopes and peat after heavy rain.
Is Dublin at risk from the sea?
About 0.4% of Dublin’s homes stand below 4 m within 2 km of the sea, against 5.7% standing low by rivers, lakes and estuaries. Coastal floods come with storm surges and spring tides; the OPW’s coastal maps on floodinfo.ie show the official picture.
How does Dublin compare with the places around it?
Radon estimates around Dublin run from 3.8% in The Liberties to 3.8% in Stoneybatter; Dublin’s own is 4.3%. Among the places measured in detail, Temple Bar has the largest share of homes standing low (27%).
Where is the nearest bathing water to Dublin?
Sandymount Strand, 5.3 km away, was rated sufficient for the 2025 season; 9 identified bathing waters lie within 15 km.
Flood: TownRatings’ estimate from ground heights, not an official flood map. Contains Irish Public Sector Data (Geological Survey Ireland, the Office of Public Works and the EPA) licensed under CC BY 4.0; Copernicus DEM © DLR e.V. and © Airbus, provided under COPERNICUS by the EU and ESA; © OpenStreetMap contributors. Radon and bathing water: EPA (CC BY 4.0). Landslide susceptibility: Geological Survey Ireland (CC BY 4.0).
Sources: low-lying homes: TownRatings’ estimate from GSI and OPW LiDAR, Copernicus GLO-30 and the EPA river network · radon: EPA radon map · landslides: GSI landslide susceptibility · flood schemes: OPW flood relief scheme benefiting areas · bathing water: EPA bathing water quality · river levels: OPW Hydro-Data (waterlevel.ie/hydro-data) · industrial sites: EPA licence registers. Under Creative Commons Attribution 4.0 (CC BY 4.0).
Contains Central Statistics Office (CSO) data, Census 2022, and Tailte Éireann boundaries (CSO Urban Areas, Small Areas, local electoral areas, constituencies), under Creative Commons Attribution 4.0 (CC BY 4.0).