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Main Street, Castle Island, Co. KerryPhoto: nick macneill · CC BY-SA 2.0
–Not graded
Flood & hazards in Castlegregory · EPA, GSI and OPW data

Beside an estuary, 17% of Castlegregory’s homes stand on low ground

Castlegregory has no Hazard risk Grade: Irish places under 1,000 residents aren’t graded. The figures below are still its own.

In brief

What stands out about Castlegregory’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.

By hazard

What Castlegregory faces

Each hazard against its own yardstick; meters run from low to high on that yardstick.

Not on this page: the OPW’s official flood maps and past floods (their licence doesn’t allow reuse here: see floodinfo.ie), groundwater and surface-water flooding, coastal erosion and industrial sites.
Hazard risk Grade

Castlegregory has no Hazard risk Grade

Radon (1.5%)Better than 79% of Irish towns
Landslide ground (0%)None on landslide-prone ground
Low-lying homes (17%)Better than 20% of Irish towns

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.

Low-lying homes

17% of Castlegregory’s homes stand low beside an 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.

By a river, lake or estuary15%of homes within 5 m of the water’s level
Near the sea2.4%of homes below 4 m, within 2 km of the sea
Measured in detail96%of homes on detailed ground heights
Where Castlegregory sits among 231 Irish towns
43%None
6%Under 0.5%
4%0.5–1%
7%1–2%
8%2–5%
6%5–10%
8%10–20%Castlegregory
18%20% +

Share of each town’s homes standing low by big water, for the towns measured in detail. 43% have none; Castlegregory has more than 80% of them.

294
homes counted
51
homes standing low by big water
15%
County Kerry’s median
0.7%
median of Irish towns

Low-lying homes across County Kerry’s towns · 4 towns measured in detail

Killarney22%
Tralee21%
Listowel9.2%
Castleisland0%

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.

Warnings

Weather and flood warnings for Castlegregory

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; Castlegregory is covered by County Kerry’s.

WarningWhat Met Éireann means by it
YellowWeather that isn’t unusual but can be dangerous in places: be aware.
OrangeInfrequent, dangerous weather that can put people and property at risk: be prepared.
RedRare, 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 Castlegregory can’t be counted here.

Met Éireann warnings · OPW river levels (waterlevel.ie)

Flood scheme

No OPW flood relief scheme protects Castlegregory

The Office of Public Works’ completed flood relief schemes and the areas each one benefits (OPW open data, CC BY 4.0).

Schemes
0
protect homes in Castlegregory
Protected places in the county
0
none in the county
Nearest protected place
86 km
Dunmanway, as the crow flies
Low-lying homes
17%
the share a scheme would be built for

None of the OPW’s completed flood relief schemes has a benefiting area that takes in Castlegregory’s homes. The OPW builds schemes where the risk to homes is greatest, so most towns have none.

No other place across County Kerry has an OPW flood relief scheme either.

The protected places nearest here
TownSchemeDesigned forHomes behind itAway
Dunmanway CorkDunmanway Flood Relief Scheme1 in 10014%86 km
Mallow CorkMallow South & West Flood Relief Scheme1 in 1002.6%95 km
Ennis ClareEnnis (Upper) Flood Relief Scheme1 in 1003.5%97 km
Annacotty LimerickMulkear River (Ballymackeogh) Flood Relief Scheme1 in 101.1%111 km
Fermoy CorkFermoy South Flood Relief Scheme1 in 1006.3%120 km
Gort GalwayGort River (Bridge Street) Drainage Scheme1 in 1000.9%122 km

Official flood maps and past floods: floodinfo.ie

Landslides

No home in Castlegregory stands 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

CastlegregoryCounty Kerry’s medianmedian of Irish towns
High or moderately high0%
0%5%

Castlegregory is among the 64% of Irish towns with no home on such ground.

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).

Radon

An estimated 1.5% of Castlegregory’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.

0% of homes estimated above the reference level · Under 1% of homes0.8% of homes estimated above the reference level · Under 1% of homes2.2% of homes estimated above the reference level · 1–5% of homes16% of homes estimated above the reference level · 10–20% (High Radon Area)under 0.1% of homes estimated above the reference level · Under 1% of homes0% of homes estimated above the reference level · Under 1% of homes0% of homes estimated above the reference level · Under 1% of homes0.2% of homes estimated above the reference level · Under 1% of homes1.5% of homes estimated above the reference level · 1–5% of homes0.8% of homes estimated above the reference level · Under 1% of homes0.8% of homes estimated above the reference level · Under 1% of homes0% of homes estimated above the reference level · Under 1% of homes39% of homes estimated above the reference level · Over 20% (High Radon Area)0% of homes estimated above the reference level · Under 1% of homes© OpenStreetMap contributors · EPA
Under 1% of homes1–5% of homes10–20% (High Radon Area)Over 20% (High Radon Area)
Share of Irish towns in each band
Under 1% of homes17%
1–5% of homes · Castlegregory38%
5–10% of homes26%
10–20% (High Radon Area)11%
Over 20% (High Radon Area)9%

A square where 10% or more of homes are estimated above the reference level is a High Radon Area; 0% of Castlegregory’s homes are in one. The map is an estimate by area: two neighbouring houses can differ a lot.

0%
of homes in a High Radon Area
3.6%
County Kerry’s median
4%
median of Irish towns

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).

Industrial sites

No EPA-licensed site within 5 km of Castlegregory: the nearest is 18 km away

Factories, farms, power plants and waste sites that hold an EPA licence for their emissions, in Castlegregory and around its centre.

0
licensed sites inside Castlegregory
0
licensed sites within 5 km of the centre
18 km
to the nearest: Dingle Civic Amenity Centre
The nearest licensed site
SiteLicence and activityAway
Dingle Civic Amenity CentreWaste licence18 km

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.

Be ready

Get ready for what Castlegregory faces

What to do, and what to ask before you move.

When the river rises
  • 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.
Met Éireann warnings · floodinfo.ie
Radon
  • 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.
radon.ie
When a storm is forecast
  • 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.
ESB Networks PowerCheck
Before you buy or rent in Castlegregory
  • Ask whether the home has ever flooded, and get a buildings insurance quote before you commit: flood cover isn’t always offered.
  • 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.
How to read these numbers

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 Castlegregory

Does Castlegregory flood?

About 17% of Castlegregory’s homes stand low beside an estuary: a higher share than in 80% 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 Castlegregory?

The EPA’s map estimates that about 1.5% of homes around Castlegregory are above the radon reference level of 200 Bq/m³: a lower share than in 79% 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 Castlegregory at risk of landslides?

No home in Castlegregory stands on ground rated high or moderately high for landslides.

Is Castlegregory at risk from the sea?

About 2.4% of Castlegregory’s homes stand below 4 m within 2 km of the sea, against 15% 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.

Where is the nearest bathing water to Castlegregory?

Castlegregory, 1.6 km away, was rated excellent for the 2025 season; 4 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 · bathing water: EPA bathing water quality · 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).