Photo: Tony Grist · Public domain

Flood & hazards in Crosby · Environment Agency

None of Crosby’s homes are at high or medium risk from rivers or the sea; 29% are from surface water

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. Crosby grades A for hazard risk: #1 of 25 in Merseyside.

1flood warnings since 2006 0%at low risk

In brief

What stands out about Crosby’s hazards

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

Rain, not the river29% of homes sit where heavy rain can flood the streets; none are at risk from rivers or the sea.1 flood warning since 2006For the parts of Crosby the Environment Agency warns directly; the most recent on 4 December 2013.Low radonEvery 1 km square over Crosby is in the lowest radon band: under 1% of homes above the action level.

By hazard

What Crosby 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.

Hazard risk Grade

Crosby grades A for hazard risk

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

Homes at high or medium flood risk (0%)Fewer than 86% 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 Crosby

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.

HighMediumLowrivers & seaHighMediumLowsurface waterCrosby’s built-up area

No home in Crosby is in the high or medium band for rivers or the sea. 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

0% of Crosby’s homes are at high or medium risk from rivers or the sea

The Environment Agency’s national map, allowing for defences. None are in the low-risk band.

High risk0%of homes · 1 in 30 a year or more0 homes, EA count

Medium risk0%of homes · 1 in 30 to 1 in 1000 homes, EA count

Low risk0%of homes · 1 in 100 to 1 in 1,0000 homes, EA count

Where Crosby sits among 3,735 UK towns

35%NoneCrosby

23%Under 0.5%

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.

Towns its size: 6th of 138 from the fewest homes at risk

#	Town	People	High or med.
1	Dudley West Midlands	64,277	0%
2	Smethwick West Midlands	56,343	0%
3	Bootle Merseyside	53,722	0%
4	Bloxwich West Midlands	51,891	0%
5	Hinckley Leicestershire	50,729	0%
6	Crosby Merseyside	50,218	0%
7	Ashton-under-Lyne Greater Manchester	48,595	0%
8	Grays Essex	44,340	0%
…
137	Tonbridge Kent	36,136	7.9%
138	Exmouth Devon	35,502	9.8%

UK towns of 35,000 to 70,000 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

29% of Crosby’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 water29%

Rivers and the sea0%

0%24.5%49% of homes

About 20% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 8.7% at medium risk: roughly 6,380 households. A further 15% face a low risk from surface water. That is more than 99% of UK towns.

~6,380

households at high or medium risk

15%

of homes at low risk

99%

of UK towns have a smaller share

28,322

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.

Flood history

Crosby has flooded in 2 recorded years since 2012

Every flood the Environment Agency has mapped inside Crosby’s built-up area, newest first. The record is fullest for big river floods; small and surface-water floods are often missing.

2013December 2013: The sea came in1 hectare inside today’s built-up area
2012September 2012: River flooding recordedUnder 1 hectare inside today’s built-up area

6 of Crosby’s households today live inside the outline of a recorded flood.

Flood warnings

No flood warning or alert is in force for Crosby · 1 warning in 20 years

The Environment Agency has 1 flood warning area and 3 alert areas reaching into the town; warnings since the service began in 2006.

Now: no flood warnings or alerts for Crosby (checked 4 November 2026, 22:45). Check for flooding on GOV.UK →

Warnings and alerts each year for areas in Crosby

Flood warning (flooding expected)Flood alert (flooding possible)

Of the 1 warnings, 1 were for Merseyside coastline at Crosby. 2013 had the most warnings (1); 2020 the most alerts (11).

The most recent warning was on 4 December 2013.

Show the 4 warning and alert areas

Area	Kind	Since 2006	Now
Merseyside coastline at Crosby	Warning area	1	None
Mersey Estuary from Liverpool and Wirral to Widnes	Alert area	49	None
Wirral catchment with Heswall, Ellesmere Port, Bebington, Hoylake and Wallasey	Alert area	21	None
Coast from Formby to Crosby	Alert area	13	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.

Radon

Crosby 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).

Under 1%

Share of the town’s area in each band

Under 1% of homes100%

Every 1 km square over Crosby 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 Crosby

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

LitherlandBootleHightownAintreeMaghullLydiateWallaseyCrosby

ABCD

Town	People	High or medium	Low	Hazard
Crosby	50,218	0%	0%	A
Litherland	18,752	0%	0%	A
Bootle	53,722	0%	0%	A
Hightown	2,018	0%	0%	A
Aintree	6,212	0%	0%	A
Maghull	20,367	1.9%	3.2%	C⁻
Lydiate	6,516	0%	under 0.1%	B⁺
Wallasey	85,619	0.2%	0.5%	B⁻

Maghull, 3.8 miles north-east, has the most homes at risk around Crosby (1.9% at high or medium).

Be ready

Get ready for what Crosby 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.
Crosby’s warning areas include Merseyside coastline at Crosby.

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 Crosby

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.
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.

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

Questions about flooding and hazards in Crosby

Does Crosby flood?

The last flood the Environment Agency recorded inside the town was in December 2013. 0% 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 29% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Crosby grades A for hazard risk against UK towns.

Which parts of Crosby are at risk of flooding?

From rivers and the sea, the places the Environment Agency warns directly: Merseyside coastline at Crosby. 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 Crosby last flood?

The recorded flood outlines inside the town run from 2012 to 2013 (2 years); the largest was in 2013. Flood warnings have been issued for parts of the town since 2006, most recently on 4 December 2013.

Is Crosby at risk of surface water flooding?

About 20% of homes are at high risk and 8.7% at medium risk from surface water, against 0% 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 Crosby?

Not by the atlas: every 1 km square over Crosby 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 Crosby now?

No flood warning or alert was in force near Crosby at 4 November 2026, 22:45. 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 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.