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BHazard risk Grade
Flood & hazards in The Glen · EPA, GSI and OPW data

Low radon and steady ground in The Glen; flooding isn’t measured here

Steady ground does most for The Glen’s grade: with 0.8% of homes on landslide-prone ground, it grades B. It counts radon and landslide ground only; flooding isn’t measured here, so it isn’t counted either way.

4%of homes over the radon level
In brief

What stands out about The Glen’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.

Flooding not measuredOnly 12% of The Glen’s homes have detailed ground heights, too few to measure how many stand low by big water.Some radonAbout 4% of homes are estimated above the radon reference level, a lower share than in 50% of Irish towns; 0% of homes are in a High Radon Area.
By hazard

What The Glen faces

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

Low-lying homes

Not measured
Too few detailed heights · 12% of homes
Check the official flood maps

Radon

4%of homes estimated over the reference level
less radon than in 50% of Irish towns
0% of homes in a High Radon Area

Landslides

0.8%of homes on high or moderately high ground
more homes on it than in 87% of Irish towns
Rated from the ground and its slope

Ground heights

12%of homes on detailed ground heights
Too few to count flood (80% needed)
Of 2,259 homes counted
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

The Glen grades B for hazard risk

Radon, landslide ground and low-lying homes, each against Irish towns, then averaged.

Radon (4%)Better than 49% of Irish towns
Landslide ground (0.8%)Better than 57% of Irish towns
Low-lying homesNot counted: not measured here

Each figure is placed among Irish towns of 1,000 or more people; the grade averages the three, so a better place on each is a better grade.

Flood isn’t counted for or against The Glen: too few of its homes have the detailed ground heights the measure needs, so its grade uses radon and landslide ground only.

The Glen isn’t ranked for hazard risk: without a flood figure its grade can’t be set beside towns whose grade counts one.

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. No full LiDAR here (12% of homes): the rest of the heights come from a 30 m satellite model, which reads roofs and trees as ground, so this town’s figure isn’t counted.

Low-lying homes

How many of The Glen’s homes stand low isn’t measured

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.

Flooding isn’t measured in The Glen: only 12% of its homes stand on LiDAR ground heights, and the measure needs 80%, so flood isn’t counted for or against it. That doesn’t mean it doesn’t flood.

A rougher estimate, mostly from a 30 m satellite model, finds few homes standing low by big water, but that model reads roofs and trees as ground, so it can’t show the town is dry.

Official flood maps and past floods: floodinfo.ie

River levels

November 2025 brought the River Glen’s 4th-highest day at Glen Park since 2013

Each winter’s highest level (October to September) at the OPW’s Glen Park gauge, in The Glen, since 2013, in metres above the gauge’s zero. Nine days in ten it runs between 0.20 m and 0.52 m.

Each winter’s highest level, metres
Winter 2013–14: highest 0.78 m · 56 days above the normal rangeWinter 2014–15: highest 0.81 m · 27 days above the normal rangeWinter 2016–17: highest 0.71 m · 12 days above the normal rangeWinter 2017–18: highest 0.89 m · 21 days above the normal rangeWinter 2018–19: highest 0.82 m · 45 days above the normal rangeWinter 2019–20: highest 0.99 m on 14 October 2019 · 36 days above the normal rangeWinter 2020–21: highest 0.87 m · 31 days above the normal rangeWinter 2021–22: highest 0.85 m · 29 days above the normal rangeWinter 2022–23: highest 1.15 m on 16 October 2022 · 76 days above the normal rangeWinter 2023–24: highest 1.31 m on 18 October 2023 · 78 days above the normal rangeWinter 2025–26: highest 1.07 m on 11 November 2025 · 53 days above the normal range’23–24’22–23’25–26Record 1.31 m, 2023Top of normal range
2013–142025–26
The highest days on record
  • 18 October 20231.31 m
  • 16 October 20221.15 m
  • 18 August 20231.10 m
  • 11 November 20251.07 m
  • 27 September 20231.06 m
  • 14 October 20190.99 m

Since 2013 the River Glen has run above its usual top on 464 days, most of them in the winters of 2023–24 and 2022–23.

Measured by its highest day, last winter (2025–26) was the 3rd-highest of the 11 on record here.

Source: OPW Hydro-Data (waterlevel.ie/hydro-data), Glen Park gauge (station 19057): 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.

Warnings

Weather and flood warnings for The Glen

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; The Glen is covered by County Cork’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 The Glen can’t be counted here.

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

Flood scheme

No OPW flood relief scheme protects The Glen

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 The Glen
Protected places in the county
3
Mallow, Fermoy, Dunmanway
Nearest protected place
27 km
Mallow, as the crow flies
Low-lying homes
Not measured
the share a scheme would be built for

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

In County Cork, OPW schemes protect parts of 3 other places, including Mallow, Fermoy, Dunmanway.

The protected places nearest here
TownSchemeDesigned forHomes behind itAway
Mallow CorkMallow South & West Flood Relief Scheme1 in 1002.6%27 km
Fermoy CorkFermoy South Flood Relief Scheme1 in 1006.3%27 km
Dunmanway CorkDunmanway Flood Relief Scheme1 in 10014%50 km
Clonmel TipperaryClonmel (North & East) Flood Relief Scheme1 in 1007.4%71 km
Annacotty LimerickMulkear River (Ballymackeogh) Flood Relief Scheme1 in 101.1%83 km
Carrick-on-Suir TipperaryCarrick-on-Suir Flood Relief Scheme1 in 504.3%86 km

Official flood maps and past floods: floodinfo.ie

Landslides

0.8% of The Glen’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

The GlenCounty Cork’s medianmedian of Irish towns
High or moderately high0.8%
0%5%

That is a higher share than in 87% of Irish towns; the median is 0.4% for County Cork’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).

Radon

An estimated 4% of The Glen’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.

1.8% of homes estimated above the reference level · 1–5% of homes8.3% of homes estimated above the reference level · 5–10% of homes7.1% of homes estimated above the reference level · 5–10% of homes13% of homes estimated above the reference level · 10–20% (High Radon Area)6.3% of homes estimated above the reference level · 5–10% of homes4% of homes estimated above the reference level · 1–5% of homes4.1% of homes estimated above the reference level · 1–5% of homes5.8% of homes estimated above the reference level · 5–10% of homes16% of homes estimated above the reference level · 10–20% (High Radon Area)1.2% of homes estimated above the reference level · 1–5% of homes21% of homes estimated above the reference level · Over 20% (High Radon Area)8.8% of homes estimated above the reference level · 5–10% of homes8.1% of homes estimated above the reference level · 5–10% of homes© OpenStreetMap contributors · EPA
1–5% of homes5–10% 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 · The Glen38%
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 The Glen’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
5.7%
County Cork’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

9 EPA-licensed sites within 5 km of The Glen’s centre, none inside it

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

0
licensed sites inside The Glen
9
licensed sites within 5 km of the centre
1.0 km
to the nearest: Rothbury Manufacturing Limited
The 8 nearest licensed sites
SiteLicence and activityAway
Rothbury Manufacturing LimitedIPC licence1.0 km
Dulux Paints Ireland LimitedIPC licence1.2 km
Heineken Ireland LimitedIPC licence1.7 km
Country Clean Recycling Unlimited CompanyIndustrial Emissions licence · waste2.2 km
Ashgrove RecyclingWaste licence2.4 km
Fronville LimitedIPC licence3.9 km
Kinsale Road LandfillIndustrial Emissions licence · waste4.4 km
Irish Pioneer Works (Fabricators) LimitedIndustrial Emissions licence · metals4.6 km
What the 21 licensed sites within 10 km do
ActivitySites
Not classed in the register6
Waste6
Chemicals6
Metals2
Solvents and coatings1

Within 5 km: 4 under Industrial Emissions licences, 4 under older IPC licences and one waste facility.

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.

Neighbours

Hazards in the places around The Glen

Low-lying homes, radon and landslide ground, town by town.

BlackpoolFarranreeMayfieldMontenotteSt Luke'sShandonBlackpoolFarranreeMayfieldMontenotteSt Luke'sShandonThe Glen
TownLow-lyingRadonLandslides
The Glen–4%0.8%
Blackpool
3,124 · 1.1 km		under 0.1%4%4.3%
Farranree
3,824 · 1.3 km		0%4%0.2%
Mayfield
2,846 · 1.4 km		–8.3%0.3%
Montenotte
4,113 · 1.4 km		–7%0%
St Luke's
4,278 · 1.5 km		5.2%4%0.6%
Shandon
3,539 · 1.8 km		9%4%0%

Of the places around The Glen, Shandon has the most homes standing low by big water (9%), 1.8 km away.

A dash under Low-lying: not measured there (too few homes with detailed ground heights), not none.

Be ready

Get ready for what The Glen 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 The Glen
  • 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 The Glen

Does The Glen flood?

For a single address, the OPW’s official flood maps and past floods are on floodinfo.ie.

Is radon a problem in The Glen?

The EPA’s map estimates that about 4% of homes around The Glen are above the radon reference level of 200 Bq/m³: a lower share than in 50% 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 The Glen at risk of landslides?

0.8% of The Glen’s homes stand on ground rated high or moderately high for landslides. Most slides happen on steep slopes and peat after heavy rain.

How does The Glen compare with the places around it?

Radon estimates around The Glen run from 4% in Blackpool to 8.3% in Mayfield; The Glen’s own is 4%. Among the places measured in detail, Shandon has the largest share of homes standing low (9%).

How is The Glen’s Hazard risk Grade worked out?

The Glen grades B: radon, landslide ground and low-lying homes are each placed among Irish towns, and the grade averages them.

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 · river levels: OPW Hydro-Data (waterlevel.ie/hydro-data) · industrial sites: EPA licence registers · the grade: TownRatings, from these figures. 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).