Guest, Sign inJoin
Fermoy WeirPhoto: Seighean · Public domain
CHazard risk Grade
Flood & hazards in Fermoy · EPA, GSI and OPW data

An estimated 9.7% of homes in Fermoy sit above the radon reference level

Its 5.9% of homes low beside the River Blackwater count against Fermoy: it grades C for hazard risk, #34 of 54 in County Cork.

5.9%of homes low-lying1 in 100flood scheme9.7%of homes over the radon level
In brief

What stands out about Fermoy’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.

Some homes low by waterAbout 5.9% of homes sit within a few metres of the River Blackwater’s level: a higher share than in 69% of Irish towns.Behind a flood schemeThe Fermoy South Flood Relief Scheme protects about 6.3% of homes, designed for a 1-in-100-year flood.Some radonAbout 9.7% of homes are estimated above the radon reference level, a higher share than in 79% of Irish towns; 7.7% of homes are in a High Radon Area.
By hazard

What Fermoy faces

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

Low-lying homes

5.9%of homes low by a big river, lake or the sea
a higher share than in 69% of Irish towns
About 120 homes

Radon

9.7%of homes estimated over the reference level
more radon than in 79% of Irish towns
7.7% of homes in a High Radon Area

Landslides

0.1%of homes on high or moderately high ground
more homes on it than in 71% of Irish towns
Rated from the ground and its slope

Flood scheme

1 in 100the flood its scheme is built for
6.3% of homes behind it
Fermoy South Flood Relief Scheme

Ground heights

100%of homes on detailed ground heights
Enough to measure flood (80% needed)
Of 1,978 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

Hazard risk in Fermoy: C

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

Radon (9.7%)Better than 25% of Irish towns
Landslide ground (0.1%)Better than 57% of Irish towns
Low-lying homes (5.9%)Better than 33% of Irish towns · counted against it

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 counts only against a town, and Fermoy’s share of low-lying homes is high enough to lower its grade.

Its place: #34 of 54 in County Cork and #237 of 321 Irish towns.

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

5.9% of Fermoy’s homes stand low beside the River Blackwater

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 estuary5.9%of homes within 5 m of the water’s level
Near the sea0%of homes below 4 m, within 2 km of the sea
Measured in detail100%of homes on detailed ground heights
Where Fermoy sits among 231 Irish towns
43%None
6%Under 0.5%
4%0.5–1%
7%1–2%
8%2–5%
6%5–10%Fermoy
8%10–20%
18%20% +

Share of each town’s homes standing low by big water, for the towns measured in detail. 43% have none; Fermoy has more than 69% of them.

Towns its size: 25th of 40, from the fewest low-lying homes
#TownPeopleLow-lying
1Dubber Dublin7,9410%
2Edenderry Offaly7,8880%
3Perrystown Dublin7,5810%
…
23Dock Limerick6,2583.7%
24Sallins Kildare6,2694.3%
25Fermoy Cork6,7205.9%
26Buncrana Donegal6,9719.6%
27Farranshone Limerick7,87411%
…
39Baldoyle Dublin7,86477%
40O'Connell Street Dublin6,749100%

The 40 Irish towns nearest its size that are measured in detail.

1,978
homes counted
~120
homes standing low by big water
5.2%
County Cork’s median
0.7%
median of Irish towns

Low-lying homes across County Cork’s towns · 15 towns measured in detail

Cork City Centre100%
Sunday's Well33%
Clonakilty27%
Youghal22%
Gillabbey14%
Shandon9%
Fermoy5.9%

Fermoy ranks 7th of County Cork’s 15 towns measured in detail, counting from the most low-lying homes.

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.

River levels

November 2024 brought the River Blackwater’s 5th-highest day at Fermoy Bridge (downstream) since 2001

Each winter’s highest level (October to September) at the OPW’s Fermoy Bridge (downstream) gauge, in Fermoy, since 2001, in metres above the gauge’s zero. Nine days in ten it runs between 0.10 m and 1.68 m.

Each winter’s highest level, metres
Winter 2001–02: highest 3.63 m · 29 days above the normal rangeWinter 2002–03: highest 3.08 m · 27 days above the normal rangeWinter 2005–06: highest 3.32 m · 30 days above the normal rangeWinter 2007–08: highest 4.22 m on 10 January 2008 · 30 days above the normal rangeWinter 2008–09: highest 3.21 m · 23 days above the normal rangeWinter 2009–10: highest 4.51 m on 20 November 2009 · 49 days above the normal rangeWinter 2010–11: highest 2.65 m · 13 days above the normal rangeWinter 2011–12: highest 3.18 m · 29 days above the normal rangeWinter 2012–13: highest 2.79 m · 31 days above the normal rangeWinter 2013–14: highest 3.81 m on 31 December 2013 · 57 days above the normal rangeWinter 2014–15: highest 3.00 m · 12 days above the normal rangeWinter 2016–17: highest 3.05 m · 10 days above the normal rangeWinter 2017–18: highest 3.62 m · 37 days above the normal rangeWinter 2018–19: highest 3.53 m · 36 days above the normal rangeWinter 2019–20: highest 2.84 m · 42 days above the normal rangeWinter 2020–21: highest 4.49 m on 24 February 2021 · 42 days above the normal rangeWinter 2021–22: highest 2.78 m · 21 days above the normal rangeWinter 2022–23: highest 3.79 m on 12 January 2023 · 44 days above the normal rangeWinter 2023–24: highest 3.16 m · 46 days above the normal rangeWinter 2024–25: highest 4.03 m on 24 November 2024 · 31 days above the normal rangeWinter 2025–26: highest 3.56 m · 37 days above the normal range’09–10’20–21Record 4.71 m, 2015Top of normal range
2001–022025–26
The highest days on record
  • 30 December 20154.71 m
  • 20 November 20094.51 m
  • 24 February 20214.49 m
  • 10 January 20084.22 m
  • 24 November 20244.03 m
  • 13 January 20103.94 m

Since 2001 the River Blackwater has run above its usual top on 676 days, most of them in the winters of 2013–14 and 2009–10.

Measured by its highest day, last winter (2025–26) was the 9th-highest of the 21 on record here.

Source: OPW Hydro-Data (waterlevel.ie/hydro-data), Fermoy Bridge (downstream) gauge (station 18107): 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 Fermoy

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; Fermoy 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 Fermoy can’t be counted here.

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

Flood scheme

2 flood relief schemes protect parts of Fermoy

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

Designed for
1 in 100 years
the flood it is built to hold back
Homes behind it
6.3%
in the area the Fermoy South Flood Relief Scheme protects
Schemes
2
Fermoy North Flood Relief Scheme · Fermoy South Flood Relief Scheme
Protected places in the county
3
across County Cork, this town included

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 Cork, OPW schemes protect parts of 2 other places, including Mallow, Dunmanway.

The protected places nearest here
TownSchemeDesigned forHomes behind itAway
Fermoy CorkFermoy South Flood Relief Scheme1 in 1006.3%–
Mallow CorkMallow South & West Flood Relief Scheme1 in 1002.6%25 km
Clonmel TipperaryClonmel (North & East) Flood Relief Scheme1 in 1007.4%46 km
Annacotty LimerickMulkear River (Ballymackeogh) Flood Relief Scheme1 in 101.1%61 km
Carrick-on-Suir TipperaryCarrick-on-Suir Flood Relief Scheme1 in 504.3%64 km
Dunmanway CorkDunmanway Flood Relief Scheme1 in 10014%74 km

Official flood maps and past floods: floodinfo.ie

Landslides

0.1% of Fermoy’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

FermoyCounty Cork’s medianmedian of Irish towns
High or moderately high0.1%
0%5%

That is a higher share than in 71% 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 9.7% of Fermoy’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.

4.9% of homes estimated above the reference level · 1–5% of homes25% of homes estimated above the reference level · Over 20% (High Radon Area)1.2% of homes estimated above the reference level · 1–5% of homes13% of homes estimated above the reference level · 10–20% (High Radon Area)20% of homes estimated above the reference level · Over 20% (High Radon Area)7.9% of homes estimated above the reference level · 5–10% of homes8.1% of homes estimated above the reference level · 5–10% of homes9.4% of homes estimated above the reference level · 5–10% of homes0.3% of homes estimated above the reference level · Under 1% of homes10% of homes estimated above the reference level · 10–20% (High Radon Area)5.6% of homes estimated above the reference level · 5–10% of homes2.1% of homes estimated above the reference level · 1–5% of homes0.2% of homes estimated above the reference level · Under 1% of homes© OpenStreetMap contributors · EPA
Under 1% of homes1–5% 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 homes38%
5–10% of homes · Fermoy26%
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; 7.7% of Fermoy’s homes are in one. The map is an estimate by area: two neighbouring houses can differ a lot.

7.7%
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

2 EPA-licensed sites lie inside Fermoy

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

2
licensed sites inside Fermoy
6
licensed sites within 5 km of the centre
0.7 km
to the nearest: Superwarm Homes (Limerick) Limited
The 7 nearest licensed sites
SiteLicence and activityAway
Superwarm Homes (Limerick) LimitedIndustrial Emissions licenceinside
Microbio (Ireland) LimitedIndustrial Emissions licence · chemicalsinside
Waste Recovery Services (Fermoy) LimitedWaste licence3.1 km
Veolia Environmental Services Technical Solutions Ltd, Corrin, Fermoy, CorkIndustrial Emissions licence · waste3.2 km
Mr Kevin AhernIndustrial Emissions licence · intensive farming3.2 km
Dairygold Agri Business LimitedIndustrial Emissions licence · intensive farming4.3 km
Mr Liam O'ConnellIndustrial Emissions licence · intensive farming6.3 km
What the 7 licensed sites within 10 km do
ActivitySites
Intensive farming3
Waste2
Not classed in the register1
Chemicals1

Within 5 km: 5 under Industrial Emissions 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 Fermoy

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

KilworthRathcormacMitchelstownWatergrasshillKilworthRathcormacMitchelstownWatergrasshillFermoy
TownLow-lyingRadonLandslides
Fermoy5.9%9.7%0.1%
Kilworth
1,179 · 5.1 km		0%0.3%0%
Rathcormac
1,957 · 6.9 km		0%9.4%0%
Mitchelstown
3,744 · 14 km		–10%0%
Watergrasshill
1,840 · 15 km		–1.2%0%

Fermoy has more of its homes standing low by big water than any measured place around it; the next is Kilworth (0%).

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

Be ready

Get ready for what Fermoy 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 Fermoy
  • 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.
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 Fermoy

Does Fermoy flood?

About 5.9% of Fermoy’s homes stand low beside the River Blackwater: a higher share than in 69% 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 Fermoy?

The EPA’s map estimates that about 9.7% of homes around Fermoy are above the radon reference level of 200 Bq/m³: a higher share than in 79% of Irish towns. 7.7% of its homes are in a High Radon Area. The only way to know a house is a three-month test.

Is Fermoy at risk of landslides?

0.1% of Fermoy’s homes stand on ground rated high or moderately high for landslides. Most slides happen on steep slopes and peat after heavy rain.

Is Fermoy at risk from the sea?

None of Fermoy’s homes stands below 4 m within 2 km of the sea, so the sea plays no part in its share of low-lying homes; 5.9% stand low by rivers, lakes and estuaries.

How does Fermoy compare with the places around it?

Radon estimates around Fermoy run from 0.3% in Kilworth to 10% in Mitchelstown; Fermoy’s own is 9.7%.

How is Fermoy’s Hazard risk Grade worked out?

Fermoy grades C: 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 · flood schemes: OPW flood relief scheme benefiting areas · 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).