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Flood & hazards in Chigwell · Environment Agency

In Chigwell, heavy rain puts more homes at risk than rivers or the sea: 10%, against under 0.1%

On the Environment Agency’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. Chigwell’s Hazard risk Grade is B: #22 of 81 in Essex.

0warnings in force0.2%at low risk
In brief

What stands out about Chigwell’s hazards

From the Environment Agency’s maps and records and the BGS radon atlas, below.

Rain, more than the river10% of homes sit where heavy rain can flood the streets, against under 0.1% at risk from rivers and the sea.The River Roding ran its 7th-highest in January 20251.67 m at Loughton on 6 January 2025, 20 cm under the record set in 2000.Low radonEvery 1 km square over Chigwell is in the lowest radon band: under 1% of homes above the action level.
By hazard

What Chigwell faces

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

Rivers and the sea

under 0.1%of homes at high or medium risk
Fewer than the typical UK town · more than 38% of towns
2 homes by the EA’s own count

Surface water

10%of homes at high or medium risk
More than 92% of UK towns
About 470 households

The River Roding

1.59 mhighest in winter 2025–26 at Loughton
15th-highest of 36 winters
Record 1.86 m, October 2000

Flood warnings

0flood warnings since 2006
84 flood alerts for the wider area
Never warned

Radon

0%of the town in a radon Affected Area
Highest band here: Under 1% of homes
No square of 5% or more
Not on this page: coastal erosion, subsidence and shrink-swell ground (the British Geological Survey licenses it), groundwater flooding and reservoir failure.
Hazard risk Grade

Chigwell grades B for hazard risk

Flood risk from rivers and the sea, against all UK towns.

Homes at high or medium flood risk (under 0.1%)Fewer than 61% of UK towns

The share of homes at high or medium risk from rivers and the sea, ranked against every UK town of 1,000 or more: fewer homes at risk is better. Towns with none at high or medium risk are ordered by their share at low risk, so they don’t all share one score. Surface water and radon aren’t graded: they are described below.

Flood map

Where the water goes in Chigwell

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.

© OpenStreetMap contributors · EA NaFRA2
HighMediumLowrivers & seaHighMediumLowsurface waterChigwell’s built-up area

The river and sea risk follows the River Roding. Surface-water risk is spread across the town, in dips, underpasses and along small streams, which is why more homes are exposed to it.

Rivers and the sea

Under 0.1% of Chigwell’s homes are at high or medium risk from rivers or the sea

The Environment Agency’s national map, allowing for defences. A further 0.2% are at low risk.

High riskunder 0.1%of homes · 1 in 30 a year or more1 homes, EA count
Medium riskunder 0.1%of homes · 1 in 30 to 1 in 1001 homes, EA count
Low risk0.2%of homes · 1 in 100 to 1 in 1,00010 homes, EA count
Where Chigwell sits among 3,735 UK towns
35%None
23%Under 0.5%Chigwell
9%0.5–1%
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; Chigwell has more than 38% of towns.

Towns its size: 109th of 382 from the fewest homes at risk
#TownPeopleHigh or med.
1Hale Greater Manchester16,7160%
2Patchway Gloucestershire16,5170%
3Wymondham Norfolk16,3340%
…
107Bishop's Cleeve Gloucestershire16,323under 0.1%
108Cudworth and Shafton South Yorkshire12,472under 0.1%
109Chigwell Essex12,251under 0.1%
110Attleborough Norfolk11,236under 0.1%
111Brimington Derbyshire11,068under 0.1%
…
381Bentley South Yorkshire12,04440%
382Dunscroft and Hatfield South Yorkshire14,00051%

UK towns of 9,000 to 17,000 people.

The Environment Agency’s Risk of Flooding from Rivers and Sea (NaFRA2, June 2026) counts each postcode’s homes by band; the shares weight those postcodes by Census 2021 households. The EA counts include homes built since 2021.

Surface water

10% of Chigwell’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 water10%
Rivers and the seaunder 0.1%
0%10.5%21% of homes

About 6.9% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 3.1% at medium risk: roughly 470 households. A further 8.5% face a low risk from surface water. That is more than 92% of UK towns.

~470
households at high or medium risk
8.5%
of homes at low risk
92%
of UK towns have a smaller share
5,225
addresses read on the map

Our estimate: every address in the town (ONS NSUL) read on the Environment Agency’s Risk of Flooding from Surface Water map (NaFRA2, 2025), 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.

River levels

The River Roding at Loughton: highest 1.86 m, in October 2000

The highest level each winter (October to September) at the Environment Agency’s Loughton gauge (Loughton), since 1990. The river normally runs between 0.03 m and 1.30 m here.

Highest level each winter, metres
Winter 1990–91: highest 0.65 m · 0 days above the normal rangeWinter 1991–92: highest 0.81 m · 0 days above the normal rangeWinter 1992–93: highest 1.39 m · 3 days above the normal rangeWinter 1993–94: highest 1.60 m · 5 days above the normal rangeWinter 1994–95: highest 1.30 m · 2 days above the normal rangeWinter 1995–96: highest 0.90 m · 0 days above the normal rangeWinter 1996–97: highest 0.31 m · 0 days above the normal rangeWinter 1997–98: highest 1.13 m · 0 days above the normal rangeWinter 1998–99: highest 1.11 m · 0 days above the normal rangeWinter 1999–00: highest 1.22 m · 0 days above the normal rangeWinter 2000–01: highest 1.86 m on 30 October 2000 · 14 days above the normal rangeWinter 2001–02: highest 1.55 m · 5 days above the normal rangeWinter 2002–03: highest 1.55 m · 10 days above the normal rangeWinter 2003–04: highest 1.22 m · 0 days above the normal rangeWinter 2004–05: highest 1.17 m · 0 days above the normal rangeWinter 2005–06: highest 0.87 m · 0 days above the normal rangeWinter 2006–07: highest 1.43 m · 4 days above the normal rangeWinter 2007–08: highest 1.41 m · 2 days above the normal rangeWinter 2008–09: highest 1.73 m on 10 February 2009 · 7 days above the normal rangeWinter 2009–10: highest 1.49 m · 16 days above the normal rangeWinter 2010–11: highest 1.63 m · 9 days above the normal rangeWinter 2011–12: highest 1.64 m · 11 days above the normal rangeWinter 2012–13: highest 1.62 m · 18 days above the normal rangeWinter 2013–14: highest 1.65 m · 25 days above the normal rangeWinter 2014–15: highest 1.60 m · 5 days above the normal rangeWinter 2015–16: highest 1.70 m on 24 June 2016 · 13 days above the normal rangeWinter 2016–17: highest 1.32 m · 1 days above the normal rangeWinter 2017–18: highest 1.41 m · 15 days above the normal rangeWinter 2018–19: highest 0.82 m · 0 days above the normal rangeWinter 2019–20: highest 1.80 m on 21 December 2019 · 18 days above the normal rangeWinter 2020–21: highest 1.73 m on 15 January 2021 · 27 days above the normal rangeWinter 2021–22: highest 1.58 m · 8 days above the normal rangeWinter 2022–23: highest 100.00 m on 9 February 2023 · 24 days above the normal rangeWinter 2023–24: highest 1.66 m · 28 days above the normal rangeWinter 2024–25: highest 1.67 m on 6 January 2025 · 6 days above the normal rangeWinter 2025–26: highest 1.59 m · 13 days above the normal range’22–23’00–01’19–20Record 1.86 m, 2000Top of normal range
1990–912025–26
The highest days on record
  • 9 February 2023100.00 m
  • 30 October 20001.86 m
  • 21 December 20191.80 m
  • 10 February 20091.73 m
  • 15 January 20211.73 m
  • 24 June 20161.70 m

The River Roding has topped its normal range on 289 days since 1990, most in the winters of 2023–24 and 2020–21. By its highest day, the winter of 2025–26 was the 15th-highest of the 36.

Environment Agency Hydrology API, Loughton (station 5470TH), daily maximum level; the record and normal range from the EA’s stage scale. Live river levels are on GOV.UK’s Check for flooding.

Flood warnings

No flood warning or alert is in force for Chigwell · 0 warnings in 20 years

The Environment Agency has 0 flood warning areas and 1 alert area reaching into the town; warnings since the service began in 2006.

Now: no flood warnings or alerts for Chigwell (checked 8 November 2026, 07:29). Check for flooding on GOV.UK →
Warnings and alerts each year for areas in Chigwell
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Flood warning (flooding expected)Flood alert (flooding possible)
Show the 1 warning and alert areas
AreaKindSince 2006Now
Middle River RodingAlert area84None

Environment Agency Historic Flood Warnings (first issues only, not updates; “flood watch” counted as an alert before 2011) and the real-time flood-monitoring API. Sign up for free warnings on GOV.UK or call Floodline, 0345 988 1188.

Radon

Chigwell is in the lowest radon 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).

TQ4291: Under 1% of homes above the action levelTQ4292: Under 1% of homes above the action levelTQ4391: Under 1% of homes above the action levelTQ4392: Under 1% of homes above the action levelTQ4393: Under 1% of homes above the action levelTQ4394: Under 1% of homes above the action levelTQ4491: Under 1% of homes above the action levelTQ4492: Under 1% of homes above the action levelTQ4493: Under 1% of homes above the action levelTQ4494: Under 1% of homes above the action levelTQ4495: Under 1% of homes above the action levelTQ4592: Under 1% of homes above the action level© OpenStreetMap contributors · BGS/UKHSA
Under 1%
Share of the town’s area in each band
Under 1% of homes100%

Every 1 km square over Chigwell is in the lowest band: fewer than 1 in 100 homes are expected to be above the action level.

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

Neighbours

Flood risk in the places around Chigwell

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

Chigwell Row: Hazard risk ABuckhurst Hill: Hazard risk B+Redbridge: Hazard risk CLoughton: Hazard risk CAbridge: Hazard risk CTheydon Bois: Hazard risk B+Waltham Forest: Hazard risk C−Chigwell RowBuckhurst HillRedbridgeLoughtonAbridgeTheydon BoisWaltham ForestChigwell
ABCD
TownPeopleHigh or mediumLowHazard
Chigwell12,251under 0.1%0.2%B
Chigwell Row2,1150%0%A
Buckhurst Hill11,7490%0.3%B+
Redbridge309,5091.4%2.3%C
Loughton33,3380.8%2%C
Abridge1,6511%0.3%C
Theydon Bois3,5400%under 0.1%B+
Waltham Forest278,1291.6%3%C−

Waltham Forest, 4.3 miles south-west, has the most homes at risk around Chigwell (1.6% at high or medium). Chigwell Row, Buckhurst Hill and Theydon Bois have none.

Be ready

Get ready for what Chigwell faces

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

Get the warnings
  • Sign up free for Environment Agency flood warnings by text, call or email.
  • Floodline: 0345 988 1188, 24 hours.
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.
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.
Before you buy or rent in Chigwell
  • Check the address on GOV.UK’s long-term flood risk service: it gives rivers and sea and surface water separately.
  • 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.
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.
  • One town, many streets. Risk is street by street. Check a specific address on GOV.UK’s long-term flood risk service before you buy or rent.

Check the long-term flood risk for an address on GOV.UK →

Questions about flooding and hazards in Chigwell

Does Chigwell flood?

Under 0.1% of homes are at high or medium risk from rivers and the sea on the Environment Agency’s maps, which allow for flood defences. About 10% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Chigwell grades B for hazard risk against UK towns.

Is Chigwell at risk of surface water flooding?

About 6.9% of homes are at high risk and 3.1% at medium risk from surface water, against under 0.1% 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 Chigwell?

Not by the atlas: every 1 km square over Chigwell is in the lowest band, where fewer than 1 in 100 homes are expected to be above the action level.

Are there flood warnings in Chigwell now?

No flood warning or alert was in force near Chigwell at 8 November 2026, 07:29. Live warnings are on GOV.UK’s Check for flooding service and Floodline, 0345 988 1188.

Contains Environment Agency information © Environment Agency and/or 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 Hydrology API (daily maximum river level) and flood-monitoring stage scales · Environment Agency real-time flood-monitoring API · Environment Agency Historic Flood Warnings (January 2006 to June 2026) and flood warning and alert areas · 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.