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Market Square, TregaronPhoto: Chris Andrews · CC BY-SA 2.0
–Not graded
Flood & hazards in Tregaron · NRW

1.5% of Tregaron’s homes are at high or medium flood risk from rivers or the sea, 1.3% 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). Tregaron has no Hazard risk Grade.

In brief

What stands out about Tregaron’s hazards

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

By hazard

What Tregaron 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 Tregaron

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.

Recorded flood: 1987© OpenStreetMap contributors · NRW FRAW
RiversSeaSurface waterdarker = higher riskTregaron’s built-up area

The river and sea risk follows the Brennig and the Teifi. Surface-water risk is patchier: dips, underpasses and small streams.

Rivers and the sea

1.5% of Tregaron’s homes are at high or medium risk from rivers or the sea

Natural Resources Wales’s national map, allowing for defences. A further 28% are at low risk.

High risk0.9%of homes · 1 in 30 a year or more
Medium risk0.6%of homes · 1 in 30 to 1 in 100 (sea: 200)
Low risk28%of homes · 1 in 100 (sea: 200) to 1 in 1,000
Where Tregaron sits among 3,735 UK towns
35%None
23%Under 0.5%
9%0.5–1%
11%1–2%Tregaron
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; Tregaron has more than 75% 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

1.3% of Tregaron’s homes are at high or medium risk from surface water

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 water1.3%
Rivers and the sea1.5%
0%17.5%35% of homes

About 1.1% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 0.2% at medium risk: roughly 10 households. A further 0.3% face a low risk from surface water. That is more than 13% of UK towns.

~10
households at high or medium risk
0.3%
of homes at low risk
13%
of UK towns have a smaller share
748
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

Tregaron has flooded in 1 recorded year since 1987

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

  1. 1987October 1987: River flooding recorded5 hectares inside today’s built-up area
The worst: 19875 ha

Floodwater covered 5 hectares of what is now Tregaron in 1987, the largest flood the record holds here (October).

75 of Tregaron’s households today live inside the outline of a recorded flood.

Flood warnings

Natural Resources Wales warns 1 area in Tregaron

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 2 warning and alert areas
AreaKindRiver or sea
Upper TeifiAlert areaTeifi
River Brennig at TregaronWarning areaBrennig

Flood warnings in Wales (NRW) →

Radon

Parts of Tregaron are in radon Affected Areas, up to the 5–10% 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).

SN6759: 5–10% of homes above the action levelSN6760: 5–10% of homes above the action levelSN6859: 5–10% of homes above the action levelSN6860: 5–10% of homes above the action level© OpenStreetMap contributors · BGS/UKHSA
5–10%
Share of the village’s area in each band
5–10% of homes100%

100% of Tregaron’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 Tregaron

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

Lampeter: Hazard risk C+LampeterTregaron
ABCD
TownPeopleHigh or mediumLowHazard
Tregaron8781.5%28%—
Lampeter2,5050.7%0.6%C+

Tregaron has more homes at high or medium risk than any neighbour in the table.

Be ready

Get ready for what Tregaron 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.
  • Tregaron’s warning areas include River Brennig at Tregaron.
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 Tregaron
  • 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 Tregaron

Does Tregaron flood?

The last flood Natural Resources Wales recorded inside the village was in October 1987. 1.5% 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 1.3% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains.

Which parts of Tregaron are at risk of flooding?

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

When did Tregaron last flood?

The recorded flood outlines inside the village run from 1987 to 1987 (1 years); the largest was in 1987.

Is Tregaron at risk of surface water flooding?

About 1.1% of homes are at high risk and 0.2% at medium risk from surface water, against 1.5% 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 Tregaron?

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 Tregaron?

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.