Photo: John Bradley · CC BY-SA 3.0Heavy rain is Maghull’s main flood risk: 26% of homes, against 1.9% from rivers or the sea
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. Maghull grades C− for hazard risk.
What stands out about Maghull’s hazards
From the Environment Agency’s maps and records and the BGS radon atlas, below.
What Maghull faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Rivers and the sea
Surface water
Past floods
The Dovers Brook
Flood warnings
Radon
Maghull grades C− for hazard risk
Flood risk from rivers and the sea, against all 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.
Where the water goes in Maghull
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.
The river and sea risk follows the River Alt, the Whinney Brook and the Dovers Brook. Surface-water risk is spread across the town, in dips, underpasses and along small streams, which is why more homes are exposed to it.
1.9% of Maghull’s homes are at high or medium risk from rivers or the sea
The Environment Agency’s national map, allowing for defences. A further 3.2% are at low risk.
Share of each UK town’s homes at high or medium risk from rivers and the sea. 35% of UK towns have none; Maghull has more than 78% of towns.
| # | Town | People | High or med. | |
|---|---|---|---|---|
| 1 | Cramlington Northumberland | 28,846 | 0% | |
| 2 | Burntwood Staffordshire | 27,891 | 0% | |
| 3 | Daventry Northamptonshire | 27,783 | 0% | |
| … | ||||
| 256 | Sevenoaks Kent | 26,474 | 1.8% | |
| 257 | Coalville Leicestershire | 21,975 | 1.8% | |
| 258 | Maghull Merseyside | 20,367 | 1.9% | |
| 259 | Hazel Grove Greater Manchester | 20,163 | 1.9% | |
| 260 | Guisborough North Yorkshire | 18,091 | 1.9% | |
| … | ||||
| 339 | Dunscroft and Hatfield South Yorkshire | 14,000 | 51% | |
| 340 | Goole East Riding of Yorkshire | 20,173 | 94% | |
UK towns of 14,000 to 29,000 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.
Heavy rain puts about 13.7 times as many Maghull homes at risk as rivers and the sea do
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.
About 18% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 7.4% at medium risk: roughly 2,280 households. A further 13% face a low risk from surface water. That is more than 99% of UK towns.
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.
Maghull has flooded in 11 recorded years since 1969
Every flood the Environment Agency has mapped inside Maghull’s built-up area, newest first. The record is fullest for big river floods; small and surface-water floods are often missing.
- 2020August 2020: River flooding recordedUnder 1 hectare inside today’s built-up area · Liverpool Road North
- 2019September 2019: The Dovers Brook overflowedUnder 1 hectare inside today’s built-up area · Dovers Brook, Maghull
- 2015December 2015: River flooding recorded1 hectare inside today’s built-up area · Sefton Lane, Maghull, Hall Lane, Maghull, Foxhouse Lane, Maghull, Powderworks Lane, Melling
- 2012September 2012: River flooding recorded1 hectare inside today’s built-up area
- 2011February 2011: River flooding recordedUnder 1 hectare inside today’s built-up area · Maghull at Hall Lane
- 2010July 2010: River flooding recordedUnder 1 hectare inside today’s built-up area · Sefton Lane
Show all 11
- 2004August 2004: The Dover's Brook overflowed2 hectares inside today’s built-up area · Dover's Brook Flooding
- 1995January 1995: River flooding recordedUnder 1 hectare inside today’s built-up area
- 1994October 1994: River flooding recordedUnder 1 hectare inside today’s built-up area
- 1970November 1970: River flooding recordedUnder 1 hectare inside today’s built-up area
- 1969November 1969: River flooding recordedUnder 1 hectare inside today’s built-up area
29 of Maghull’s households today live inside the outline of a recorded flood.
The Dovers Brook in January 2025 rose to its highest level since 2013
The highest level each winter (October to September) at the Environment Agency’s Dovers Bridge gauge (Sefton), since 2013. The river normally runs between 0.20 m and 1.76 m here.
- 1 January 20252.59 m
- 20 January 20212.56 m
- 24 July 20232.54 m
- 4 October 20202.54 m
- 30 September 20242.49 m
- 21 October 20232.40 m
The Dovers Brook has topped its normal range on 15 days since 2013, most in the winters of 2018–19 and 2022–23. By its highest day, the winter of 2025–26 was the 3rd-highest of the 5.
Environment Agency Hydrology API, Dovers Bridge (station 694748), 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.
No flood warning or alert is in force for Maghull · 43 warnings in 20 years
The Environment Agency has 3 flood warning areas and 1 alert area reaching into the town; warnings since the service began in 2006.
Of the 43 warnings, 20 were for Whinney Brook and Dovers Brook at Maghull, around Sefton Lane and the Waste Transfer Station and 12 for Whinney Brook and Dovers Brook at Maghull, beside Hall Lane, Fouracres and Sefton Lane. 2019 had the most warnings (10); 2024 the most alerts (12).
The most recent warning was on 1 January 2025.
Show the 4 warning and alert areas
| Area | Kind | Since 2006 | Now |
|---|---|---|---|
| Whinney Brook and Dovers Brook at Maghull, around Sefton Lane and the Waste Transfer Station | Warning area | 20 | None |
| Whinney Brook and Dovers Brook at Maghull, beside Hall Lane, Fouracres and Sefton Lane | Warning area | 12 | None |
| Fouracres and The Crescent at Maghull | Warning area | 11 | None |
| River Alt, Formby to Huyton | Alert area | 64 | None |
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.
Maghull 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).
Every 1 km square over Maghull 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.
Flood risk in the places around Maghull
Share of homes at high or medium and at low risk from rivers and the sea. Tap a town for its page.
Maghull has more homes at high or medium risk than any neighbour in the table.
Get ready for what Maghull faces
Free warnings, what to do in a cloudburst, and what to check before you move.
- Sign up free for Environment Agency flood warnings by text, call or email.
- Floodline: 0345 988 1188, 24 hours.
- Maghull’s warning areas include Whinney Brook and Dovers Brook at Maghull, beside Hall Lane, Fouracres and Sefton Lane and Whinney Brook and Dovers Brook at Maghull, around Sefton Lane and the Waste Transfer Station.
- 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.
- 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.
- 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.
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 GOV.UK’s long-term flood risk service before you buy or rent.
Questions about flooding and hazards in Maghull
Does Maghull flood?
The last flood the Environment Agency recorded inside the town was in August 2020. 1.9% 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 26% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Maghull grades C− for hazard risk against UK towns.
Which parts of Maghull are at risk of flooding?
From rivers and the sea, the places the Environment Agency warns directly: Whinney Brook and Dovers Brook at Maghull, around Sefton Lane and the Waste Transfer Station, Whinney Brook and Dovers Brook at Maghull, beside Hall Lane, Fouracres and Sefton Lane and Fouracres and The Crescent at Maghull. Surface water can collect in low spots anywhere in the town. Check a specific address on GOV.UK’s long-term flood risk service.
When did Maghull last flood?
The recorded flood outlines inside the town run from 1969 to 2020 (11 years); the largest was in 2004. Flood warnings have been issued for parts of the town since 2006, most recently on 1 January 2025.
Is Maghull at risk of surface water flooding?
About 18% of homes are at high risk and 7.4% at medium risk from surface water, against 1.9% 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 Maghull?
Not by the atlas: every 1 km square over Maghull 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 Maghull now?
No flood warning or alert was in force near Maghull at 3 November 2026, 12:55. 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 Recorded Flood Outlines and Natural Resources Wales historic flood map, inside the ONS 2022 built-up-area boundary · 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.