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Boyle's Bar, Slane, Co. MeathPhoto: Nigel Thompson · CC BY-SA 2.0
D−Hazard risk Grade
Flood & hazards in Slane · EPA, GSI and OPW data

In Slane, radon is the measure to watch: about 15% of homes are estimated over the reference level

Landslide ground weighs most on Slane’s grade: with 4.8% of homes on it, it grades D−. Radon and landslide ground set it: its share of low-lying homes would have lifted the grade, and flood only ever counts against a town.

15%of homes over the radon level
In brief

What stands out about Slane’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.

Few homes by big waterUnder 2% of homes stand low by a big river, lake or the sea. Small streams, drains and groundwater aren’t in that measure.High radonAn estimated 15% of homes are above the radon reference level: a higher share than in 86% of Irish towns.Landslide-prone ground4.8% of homes stand on ground rated high or moderately high for landslides: a higher share than in 98% of Irish towns.
By hazard

What Slane faces

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

Low-lying homes

0.3%of homes low by a big river, lake or the sea
a lower share than in 52% of Irish towns
About 2 homes

Radon

15%of homes estimated over the reference level
more radon than in 86% of Irish towns
100% of homes in a High Radon Area

Landslides

4.8%of homes on high or moderately high ground
more homes on it than in 98% of Irish towns
Rated from the ground and its slope

Ground heights

100%of homes on detailed ground heights
Enough to measure flood (80% needed)
Of 582 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

Slane grades D− for hazard risk

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

Radon (15%)Better than 16% of Irish towns
Landslide ground (4.8%)Better than 2% of Irish towns
Low-lying homes (0.3%)Not counted: it would have raised the grade

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, never for it: Slane’s share of low-lying homes would have raised its grade, so it isn’t counted, and radon and landslide ground set it.

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

Few of Slane’s homes stand low by a big river, lake or the sea

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. Smaller streams, drains and groundwater aren’t in this measure, so a low figure doesn’t mean a town never floods.

By a river, lake or estuary0.3%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 Slane sits among 231 Irish towns
43%None
6%Under 0.5%Slane
4%0.5–1%
7%1–2%
8%2–5%
6%5–10%
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; Slane has more than 48% of them.

582
homes counted
2
homes standing low by big water
0%
County Meath’s median
0.7%
median of Irish towns

Low-lying homes across County Meath’s towns · 5 towns measured in detail

Trim1.7%
Navan1.5%
Dunboyne0%
Enfield0%
Athboy0%

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

The River Boyne at Slane Castle peaked at 2.85 m in December 1954

Each winter’s highest level (October to September) at the OPW’s Slane Castle gauge, 0.5 km from Slane on the same river, since 1940, in metres above the gauge’s zero. Nine days in ten it runs between 0.51 m and 1.50 m.

Each winter’s highest level, metres
Winter 1940–41: highest 1.92 m · 36 days above the normal rangeWinter 1941–42: highest 1.74 m · 17 days above the normal rangeWinter 1942–43: highest 1.69 m · 14 days above the normal rangeWinter 1943–44: highest 1.55 m · 3 days above the normal rangeWinter 1944–45: highest 2.05 m · 42 days above the normal rangeWinter 1945–46: highest 2.27 m · 30 days above the normal rangeWinter 1946–47: highest 2.30 m · 46 days above the normal rangeWinter 1947–48: highest 2.31 m · 35 days above the normal rangeWinter 1948–49: highest 1.87 m · 17 days above the normal rangeWinter 1949–50: highest 1.77 m · 14 days above the normal rangeWinter 1950–51: highest 1.75 m · 12 days above the normal rangeWinter 1951–52: highest 1.88 m · 35 days above the normal rangeWinter 1952–53: highest 1.53 m · 1 days above the normal rangeWinter 1953–54: highest 1.82 m · 7 days above the normal rangeWinter 1954–55: highest 2.85 m on 9 December 1954 · 64 days above the normal rangeWinter 1955–56: highest 1.67 m · 4 days above the normal rangeWinter 1956–57: highest 1.78 m · 17 days above the normal rangeWinter 1957–58: highest 1.95 m · 30 days above the normal rangeWinter 1958–59: highest 1.51 m · 1 days above the normal rangeWinter 1959–60: highest 1.88 m · 43 days above the normal rangeWinter 1960–61: highest 2.01 m · 46 days above the normal rangeWinter 1961–62: highest 1.64 m · 8 days above the normal rangeWinter 1962–63: highest 1.70 m · 7 days above the normal rangeWinter 1963–64: highest 1.68 m · 10 days above the normal rangeWinter 1964–65: highest 2.05 m · 36 days above the normal rangeWinter 1965–66: highest 2.31 m · 64 days above the normal rangeWinter 1966–67: highest 1.83 m · 14 days above the normal rangeWinter 1967–68: highest 2.08 m · 24 days above the normal rangeWinter 1968–69: highest 2.25 m · 39 days above the normal rangeWinter 1969–70: highest 1.77 m · 8 days above the normal rangeWinter 1970–71: highest 1.77 m · 13 days above the normal rangeWinter 1971–72: highest 1.62 m · 2 days above the normal rangeWinter 1972–73: highest 1.37 m · 0 days above the normal rangeWinter 1973–74: highest 1.50 m · 0 days above the normal rangeWinter 1974–75: highest 1.98 m · 18 days above the normal rangeWinter 1975–76: highest 1.53 m · 4 days above the normal rangeWinter 1976–77: highest 1.70 m · 23 days above the normal rangeWinter 1977–78: highest 1.82 m · 8 days above the normal rangeWinter 1978–79: highest 2.64 m on 28 December 1978 · 19 days above the normal rangeWinter 1979–80: highest 2.54 m on 19 March 1980 · 50 days above the normal rangeWinter 1980–81: highest 2.23 m · 17 days above the normal rangeWinter 1981–82: highest 2.04 m · 24 days above the normal rangeWinter 1982–83: highest 2.38 m · 40 days above the normal rangeWinter 1983–84: highest 2.20 m · 38 days above the normal rangeWinter 1984–85: highest 2.35 m · 26 days above the normal rangeWinter 1985–86: highest 2.23 m · 18 days above the normal rangeWinter 1986–87: highest 1.90 m · 17 days above the normal rangeWinter 1987–88: highest 2.14 m · 34 days above the normal rangeWinter 1988–89: highest 1.53 m · 2 days above the normal rangeWinter 1989–90: highest 2.50 m on 7 February 1990 · 20 days above the normal rangeWinter 1990–91: highest 2.04 m · 27 days above the normal rangeWinter 1991–92: highest 2.18 m · 8 days above the normal rangeWinter 1992–93: highest 2.49 m · 11 days above the normal rangeWinter 1993–94: highest 2.15 m · 50 days above the normal rangeWinter 1994–95: highest 2.50 m · 34 days above the normal rangeWinter 1995–96: highest 2.25 m · 19 days above the normal rangeWinter 1996–97: highest 1.77 m · 10 days above the normal rangeWinter 1997–98: highest 1.94 m · 21 days above the normal rangeWinter 1998–99: highest 2.33 m · 26 days above the normal rangeWinter 1999–00: highest 2.01 m · 17 days above the normal rangeWinter 2000–01: highest 2.65 m on 6 November 2000 · 19 days above the normal rangeWinter 2001–02: highest 2.23 m · 21 days above the normal rangeWinter 2002–03: highest 2.54 m on 15 November 2002 · 30 days above the normal rangeWinter 2003–04: highest 1.88 m · 8 days above the normal rangeWinter 2004–05: highest 2.41 m · 10 days above the normal rangeWinter 2005–06: highest 1.66 m · 7 days above the normal rangeWinter 2006–07: highest 2.19 m · 34 days above the normal rangeWinter 2007–08: highest 2.51 m on 17 August 2008 · 35 days above the normal rangeWinter 2008–09: highest 1.77 m · 6 days above the normal rangeWinter 2009–10: highest 2.49 m · 33 days above the normal rangeWinter 2010–11: highest 2.21 m · 23 days above the normal rangeWinter 2012–13: highest 2.30 m · 20 days above the normal rangeWinter 2013–14: highest 2.16 m · 45 days above the normal rangeWinter 2014–15: highest 2.23 m · 16 days above the normal rangeWinter 2015–16: highest 2.41 m · 58 days above the normal rangeWinter 2016–17: highest 1.52 m · 1 days above the normal rangeWinter 2017–18: highest 2.18 m · 16 days above the normal rangeWinter 2018–19: highest 2.27 m · 16 days above the normal rangeWinter 2019–20: highest 2.70 m on 24 February 2020 · 84 days above the normal rangeWinter 2021–22: highest 2.21 m · 19 days above the normal rangeWinter 2022–23: highest 2.15 m · 56 days above the normal rangeWinter 2023–24: highest 2.14 m · 52 days above the normal rangeWinter 2024–25: highest 1.51 m · 1 days above the normal rangeWinter 2025–26: highest 2.42 m · 61 days above the normal range’54–55’19–20’00–01Record 2.85 m, 1954Top of normal range
1940–412025–26
The highest days on record
  • 9 December 19542.85 m
  • 24 February 20202.70 m
  • 6 November 20002.65 m
  • 28 December 19782.64 m
  • 19 March 19802.54 m
  • 15 November 20022.54 m

Since 1940 the River Boyne has run above its usual top on 1,991 days, most of them in the winters of 2019–20 and 1954–55.

Measured by its highest day, last winter (2025–26) was the 12th-highest of the 84 on record here.

The OPW gives the bank-full level here as 2.00 m: above it the river spills out of its channel.

Source: OPW Hydro-Data (waterlevel.ie/hydro-data), Slane Castle gauge (station 07012): 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 Slane

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; Slane is covered by County Meath’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 Slane can’t be counted here.

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

Flood scheme

No OPW flood relief scheme protects Slane

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 Slane
Protected places in the county
4
Laytown-Bettystown-Mornington-Donacarney, Dunboyne, Duleek, Clonee
Nearest protected place
9.7 km
Duleek, as the crow flies
Low-lying homes
0.3%
the share a scheme would be built for

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

In County Meath, OPW schemes protect parts of 4 other places, including Laytown-Bettystown-Mornington-Donacarney, Dunboyne, Duleek, Clonee.

The protected places nearest here
TownSchemeDesigned forHomes behind itAway
Duleek MeathDuleek Flood Relief Scheme1 in 10012%9.7 km
Laytown-Bettystown-Mornington-Donacarney MeathMornington Flood Relief Scheme1 in 1009.1%18 km
Dunboyne MeathRiver Tolka (Clonee and Dunboyne) Scheme1 in 10014%33 km
Clonee MeathRiver Tolka (Clonee and Dunboyne) Scheme1 in 10057%34 km
Mulhuddart DublinRiver Tolka (Fingal) Flood Relief Scheme1 in 100under 0.1%36 km
Clonsilla DublinRiver Tolka (Clonee and Dunboyne) Scheme1 in 1000.5%36 km

Official flood maps and past floods: floodinfo.ie

Landslides

4.8% of Slane’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

SlaneCounty Meath’s medianmedian of Irish towns
High or moderately high4.8%
0%10%

That is a higher share than in 98% of Irish towns; the median is 0% for County Meath’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 15% of Slane’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.

10% of homes estimated above the reference level · 10–20% (High Radon Area)15% of homes estimated above the reference level · 10–20% (High Radon Area)1.2% of homes estimated above the reference level · 1–5% of homes1.3% of homes estimated above the reference level · 1–5% of homes0% of homes estimated above the reference level · Under 1% of homes0.4% 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 homes31% of homes estimated above the reference level · Over 20% (High Radon Area)29% of homes estimated above the reference level · Over 20% (High Radon Area)6.8% of homes estimated above the reference level · 5–10% 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 homes26%
10–20% (High Radon Area) · Slane11%
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; 100% of Slane’s homes are in one. The map is an estimate by area: two neighbouring houses can differ a lot.

100%
of homes in a High Radon Area
0.5%
County Meath’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

3 EPA-licensed sites within 5 km of Slane’s centre, none inside it

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

0
licensed sites inside Slane
3
licensed sites within 5 km of the centre
4.4 km
to the nearest: C & N Oils Limited
The 8 nearest licensed sites
SiteLicence and activityAway
C & N Oils LimitedIndustrial Emissions licence4.4 km
Dawn Meats Ireland Unlimited CompanyIndustrial Emissions licence · food and drink4.7 km
Mr Dermot CrinionIndustrial Emissions licence · intensive farming4.7 km
Starrus Eco Holdings Limited (Slane)Industrial Emissions licence · waste5.0 km
JCM Farm LimitedIndustrial Emissions licence · intensive farming5.5 km
Broomfield Pig Farm LimitedIndustrial Emissions licence · intensive farming6.0 km
Knockharley LandfillIndustrial Emissions licence · waste7.2 km
Mr David MurrayIndustrial Emissions licence · intensive farming8.3 km
What the 10 licensed sites within 10 km do
ActivitySites
Intensive farming5
Waste3
Not classed in the register1
Food and drink1

Within 5 km: 3 under Industrial Emissions licences.

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 Slane

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

TullyallenKentstownDuleekNavanDroghedaArdeeTullyallenKentstownDuleekNavanDroghedaArdeeSlane
TownLow-lyingRadonLandslides
Slane0.3%15%4.8%
Tullyallen
1,697 · 8.9 km		–1.3%0%
Kentstown
1,195 · 8.9 km		–6.8%0%
Duleek
4,899 · 9.7 km		–10%0%
Navan
33,886 · 11 km		1.5%0%under 0.1%
Drogheda
44,135 · 13 km		1.6%1.1%under 0.1%
Ardee
5,478 · 16 km		35%1.6%0%

Of the places around Slane, Ardee has the most homes standing low by big water (35%), 16 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 Slane 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 Slane
  • 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.
  • On a slope, ask the seller about cracks, drainage and any past ground movement.
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 Slane

Does Slane flood?

Smaller streams, drains and groundwater aren’t in that measure, so it doesn’t mean the town never floods. For a single address, the OPW’s official flood maps and past floods are on floodinfo.ie.

Is radon a problem in Slane?

The EPA’s map estimates that about 15% of homes around Slane are above the radon reference level of 200 Bq/m³: a higher share than in 86% of Irish towns. 100% of its homes are in a High Radon Area. The only way to know a house is a three-month test.

Is Slane at risk of landslides?

4.8% of Slane’s homes stand on ground rated high or moderately high for landslides. Most slides happen on steep slopes and peat after heavy rain.

Is Slane at risk from the sea?

None of Slane’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; 0.3% stand low by rivers, lakes and estuaries.

How does Slane compare with the places around it?

Radon estimates around Slane run from 0% in Navan to 10% in Duleek; Slane’s own is 15%. Among the places measured in detail, Ardee has the largest share of homes standing low (35%).

How is Slane’s Hazard risk Grade worked out?

Slane grades D−: 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).