floodchecker

POSTCODES IN SW4

936 postcodes checked

Low river/sea risk
Flood Zone 3
0% · 0
Flood Zone 2
0% · 0
Flood Zone 1
100% · 936

Rivers and the sea, Environment Agency Flood Map for Planning. Counts postcodes, not homes.

Flood risk in SW4 (Lambeth)

Of the 936 postcodes in SW4 – covering Lambeth – none has its centre in Flood Zone 2 or 3 on the Environment Agency’s Flood Map for Planning. River and sea flood risk across the district is low.

Flood zones only cover rivers and the sea, and ignore flood defences. Surface water from heavy rain can affect any street, including in Zone 1.

Flood zones by postcode sector

Each sector is the first part of the postcode plus the first digit after the space.

Postcodes in Flood Zones 2 and 3, by postcode sector in SW4
SectorPostcodesZone 3Zone 2
SW4 01690%0%
SW4 4150%0%
SW4 61980%0%
SW4 72000%0%
SW4 81700%0%
SW4 91840%0%

Main rivers in London

  • River Thames – Tidal from Teddington Lock to the estuary

  • River Lea – The Lee Valley, Stratford and Bow Creek

  • River Wandle – Croydon, Merton and Wandsworth

More on the area in our London flood risk guide.

How these figures are worked out

We took the centre point of every live postcode in SW4 from OS Code-Point Open and tested it against the Environment Agency’s Flood Map for Planning, as published in the flood-risk-zone dataset (version of 5 November 2026). A postcode counts once, whether it has one home or forty, and a postcode whose centre is just outside a zone still counts as Zone 1. Updated November 2026.

For one address, the free postcode check looks at the zones around the postcode, and the full report adds surface water, reservoirs, recorded floods and defences.

FAQ

SW4 flood questions

None of the 936 postcodes in SW4 has its centre in Flood Zone 2 or 3, so the district is in Flood Zone 1 – low probability of flooding from rivers and the sea. Surface water flooding is mapped separately.

Check a SW4 postcode

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