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The village green, PenallyPhoto: Humphrey Bolton · CC BY-SA 2.0
–Not graded
Flood & hazards in Penally · NRW

In Penally, 0.8% of homes face high or medium risk from rivers or the sea and 0.4% from surface water

On Natural Resources Wales’s maps, which allow for flood defences, “high or medium” means at least a 1 in 100 chance of flooding from rivers or the sea in any year (1 in 200 for the sea in Wales). Penally has no Hazard risk Grade.

In brief

What stands out about Penally’s hazards

From Natural Resources Wales’s maps and records and the BGS radon atlas, below.

By hazard

What Penally faces

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

Not on this page: coastal erosion, subsidence and shrink-swell ground (the British Geological Survey licenses it), groundwater flooding and reservoir failure.
Flood map

Where the water goes in Penally

Turn layers on and off. Blue is the risk from rivers and the sea; pink is where heavy rain collects. Both allow for flood defences.

Knightson Brook: 1990Recorded flood: 2012Recorded flood: 2025© OpenStreetMap contributors · NRW FRAW
RiversSeaSurface waterdarker = higher riskPenally’s built-up area

The river and sea risk follows the Ritec and the Irish Sea. Surface-water risk is patchier: dips, underpasses and small streams.

Rivers and the sea

0.8% of Penally’s homes are at high or medium risk from rivers or the sea

Natural Resources Wales’s national map, allowing for defences. A further 1.4% are at low risk.

High risk0.7%of homes · 1 in 30 a year or more
Medium riskunder 0.1%of homes · 1 in 30 to 1 in 100 (sea: 200)
Low risk1.4%of homes · 1 in 100 (sea: 200) to 1 in 1,000
Where Penally sits among 3,735 UK towns
35%None
23%Under 0.5%
9%0.5–1%Penally
11%1–2%
11%2–5%
5%5–10%
3%10–20%
2%20% +

Share of each UK town’s homes at high or medium risk from rivers and the sea. 35% of UK towns have none; Penally has more than 64% of towns.

Natural Resources Wales’s Flood Risk Assessment Wales map (May 2026) tested against every address in the village (ONS NSUL), weighted by Census 2021 households. Rivers and sea can overlap; the worse band counts.

Surface water

Rivers and the sea, more than heavy rain, are Penally’s flood risk

Surface water is rain that falls faster than drains and the ground can take it. It is mapped separately from rivers and the sea, and it is not in the Hazard risk Grade.

Surface water0.4%
Rivers and the sea0.8%
0%7%14% of homes

About 0.3% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and under 0.1% at medium risk. A further 0% face a low risk from surface water. That is more than 4% of UK towns.

0
households at high or medium risk
0%
of homes at low risk
4%
of UK towns have a smaller share
732
addresses read on the map

Our estimate: every address in the village (ONS NSUL) read on Natural Resources Wales’s Flood Risk Assessment Wales map of surface water and small watercourses, each postcode’s share weighted by its Census 2021 households. Neither agency publishes a count of homes for surface water, so treat it as a guide; one street can differ from the next.

Flood history

Penally has flooded in 3 recorded years since 1990, most of all in 2012

Every flood Natural Resources Wales has mapped inside Penally’s built-up area, newest first. The record is fullest for big river floods; small and surface-water floods are often missing.

  1. 2025November 2025: River flooding recorded6 hectares inside today’s built-up area
  2. 2012December 2012: River flooding recorded10 hectares inside today’s built-up area · Tenby Flood History
  3. 1990April 1990: The Knightson Brook overflowed8 hectares inside today’s built-up area · Ritec and Knightson Brook Flooding
The worst: 201210 ha

Floodwater covered 10 hectares of what is now Penally in 2012, the largest flood the record holds here (December).

1 of Penally’s households today live inside the outline of a recorded flood.

Since 2012, the largest recorded flood inside the village covered 6 hectares.

Flood warnings

Natural Resources Wales warns 1 area in Penally

Natural Resources Wales issues flood alerts and warnings for Wales; the Environment Agency’s live service covers England only. Both run Floodline, 0345 988 1188.

Show the 3 warning and alert areas
AreaKindRiver or sea
Pembrokeshire coastAlert areaIrish Sea
South PembrokeshireAlert areaRitec
River Ritec at TenbyWarning areaRitec

Flood warnings in Wales (NRW) →

Radon

Parts of Penally are in radon Affected Areas, up to the 10–30% band

Radon is a natural radioactive gas from the ground; long exposure raises the risk of lung cancer. The atlas gives the chance that a home in each 1 km square is above the UK action level (200 Bq/m³).

SS1098: 10–30% of homes above the action levelSS1099: 10–30% of homes above the action levelSS1198: 10–30% of homes above the action levelSS1199: 10–30% of homes above the action levelSN1100: 10–30% of homes above the action levelSS1299: 10–30% of homes above the action levelSN1200: 10–30% of homes above the action level© OpenStreetMap contributors · BGS/UKHSA
10–30%
Share of the village’s area in each band
10–30% of homes100%

100% of Penally’s built-up area is in a radon Affected Area (1% of homes or more above the action level), and 100% in squares of 5% or more.

The squares are indicative: each takes the highest band found anywhere inside it, so most homes in a coloured square are below it. Only a three-month test in the home gives a real answer.

BGS/UKHSA Indicative Atlas of Radon in Great Britain, version 3. Check an address at UKradon.org.

Neighbours

Flood risk in the places around Penally

Share of homes at high or medium and at low risk from rivers and the sea. Tap a town for its page.

ABCD
TownPeopleHigh or mediumLowHazard
Penally8070.8%1.4%—
Tenby4,0920.3%1.1%B−
Saundersfoot2,5151.1%0.8%C
Wooden1,3000%0%A
Kilgetty1,2470%0%A
Pembroke7,9633%0.3%C−
Pembroke Dock9,6591.2%0.7%C
Narberth2,3650.2%under 0.1%B−

Pembroke, 8.4 miles west, has the most homes at risk around Penally (3% at high or medium). Wooden and Kilgetty have none.

Be ready

Get ready for what Penally faces

Free warnings, what to do in a cloudburst, and what to check before you move.

Get the warnings
  • Sign up free for Natural Resources Wales flood warnings by text, call or email.
  • Floodline: 0345 988 1188, 24 hours.
  • Penally’s warning areas include River Ritec at Tenby.
Sign up ↗
In a cloudburst
  • Surface water rises in minutes, often with no warning issued: stay out of underpasses and dips.
  • Keep the gullies and drains outside your home clear of leaves.
  • Report a blocked road drain to the council.
Radon
  • Test over three months, in a living room and a bedroom.
  • Above 200 Bq/m³, a small sump and fan usually fixes it.
  • New homes in radon areas are built with protection: basic from 3%, full from 10%.
UKradon ↗
Before you buy or rent in Penally
  • Check the address on Natural Resources Wales’s flood map: it shows rivers, the sea and surface water.
  • Ask whether the home has flooded or had a flood insurance claim; the TA6 property form asks the seller.
  • Homes built before 2009 can get flood cover through Flood Re, the government-backed scheme; newer homes can’t.
  • Check radon for the address on UKradon.org (a small fee) or ask the seller for a test result.
How to read these numbers

What this data can and can’t tell you

  • Defences are counted. Both agencies’ maps allow for flood defences and the chance they are overtopped or fail, so a town behind a defence scheme can show few homes at high risk and many at low risk.
  • Surface water is our estimate. Neither agency publishes a count of homes at risk from surface water, so we read each address on the map. A flat on a hill and a basement in a dip can share a postcode.
  • Past floods are what was recorded. The flood outlines come from surveys, aerial photographs and reports; many small floods, and most surface-water floods, were never mapped.
  • One town, many streets. Risk is street by street. Check a specific address on Natural Resources Wales’s flood risk map before you buy or rent.
  • Wales is measured slightly differently. NRW publishes no count of homes at risk, so each address in the village is tested against its map. Addresses include garages, chapels and shops, and NRW’s medium band for the sea runs to 1 in 200 (England’s stops at 1 in 100), so Welsh figures lean a little higher than English ones.

Natural Resources Wales flood risk map →

Questions about flooding and hazards in Penally

Does Penally flood?

The last flood Natural Resources Wales recorded inside the village was in November 2025. 0.8% of homes are at high or medium risk from rivers and the sea on Natural Resources Wales’s maps, which allow for flood defences. About 0.4% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains.

Which parts of Penally are at risk of flooding?

From rivers and the sea, the places Natural Resources Wales warns directly: River Ritec at Tenby. Surface water can collect in low spots anywhere in the village. Check a specific address on NRW’s flood risk map.

When did Penally last flood?

The recorded flood outlines inside the village run from 1990 to 2025 (3 years); the largest was in 2012.

Is Penally at risk of surface water flooding?

About 0.3% of homes are at high risk and under 0.1% at medium risk from surface water, against 0.8% at high or medium risk from rivers and the sea. Surface water floods come with little warning, and the agencies don’t issue warnings for them.

Is radon a problem in Penally?

100% of the village’s built-up area is in a radon Affected Area on the BGS/UKHSA atlas, and 100% is in 1 km squares where 5% or more of homes may be above the action level. Most homes are below it; a three-month test is the only way to know.

Where can I find flood warnings for Penally?

Natural Resources Wales issues flood warnings and alerts for Wales on its flood warnings service, and runs Floodline (0345 988 1188) with the Environment Agency.

Contains Natural Resources Wales information © Natural Resources Body for Wales and database right. Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Contains British Geological Survey materials © UKRI 2026.

Sources: Environment Agency Risk of Flooding from Rivers and Sea, postcodes in areas at risk (June 2026); Natural Resources Wales Flood Risk Assessment Wales (May 2026); ONS Census 2021 households by postcode · Environment Agency Risk of Flooding from Surface Water (NaFRA2, 2025) and Natural Resources Wales Flood Risk Assessment Wales surface water and small watercourses, read at every address (ONS National Statistics UPRN Lookup, September 2026) and weighted by Census 2021 households by postcode · Environment Agency Recorded Flood Outlines and Natural Resources Wales historic flood map, inside the ONS 2022 built-up-area boundary · BGS/UKHSA Indicative Atlas of Radon in Great Britain, version 3, by 1 km square · TownRatings grades: our own summary of the data, ranked against UK towns only. All under the Open Government Licence v3.0.

Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.