Does KT21 flood?

Yes — parts of the KT21 district carry real flood risk: 4 of its 6 at-risk postcodes reach the Environment Agency's High likelihood band. The KT21 postcode district covers Ashtead Lanes & Common, close to Leatherhead, Ewell, Tolworth, and surrounding villages in parts of England and Surrey.

6 postcodes in the KT21 district appear in the Environment Agency's rivers-and-sea flood-risk dataset — worst bands: 4 high, 2 low. A postcode not listed here has no properties in any recorded risk band (which is good news, but never proof it cannot flood).

Free preview first · full report £19

Which KT21 postcodes are at risk?

KT21 1PZ up to High KT21 1QD up to High KT21 2ED up to High KT21 2EQ up to High KT21 1QB up to Low KT21 1QF up to Low

Rivers and flooding history near KT21

The rivers that matter here, each monitored live on FloodRadar:

Leatherhead on the River Mole — 3.5 km away, highest on record 3.74m
Bourne Hall GS — 5.1 km away
Ewell on the Hogsmill River — 5.3 km away, highest on record 0.80m
Ewell GS — 5.4 km away

407 official flood warnings and alerts have been raised within ~10 km of the district's centre since 2006 (56 at warning level or above), most recently 30 March 2026. Warnings cover flood areas, not individual addresses.

Recorded flood extents near the district (Environment Agency record):

LeatherheadSTW_Dec2013 (2013) — about 3.8 km from the centre
LeatherheadUS2_Dec2013 (2013) — about 3.6 km from the centre
LeatherheadDS1_Dec2013 (2013) — about 3.7 km from the centre
February 1990 flooding — about 3.6 km from the centre

Records, not floods: no outline on the record is not evidence a place has not flooded.

🏠 Buying or renting in KT21? The full property flood-risk report covers any postcode here — the official likelihood band, every recorded flood nearby with distances, warning history year by year, how the local rivers behave, and an insurance outlook, print-ready for £19. See what's in the report →

Flood risk in nearby postcode districts

KT22 KT19 KT23 KT18 KT24 KT17 KT16 KT15

Band = the worst likelihood band of any property in that postcode (EA Risk of Flooding from Rivers & Sea, defence-adjusted, area-level). Check any postcode in detail — or get the full £19 property report — at the property flood-risk report. © Environment Agency copyright and/or database right 2025. All rights reserved. Some features of this map are based on digital spatial data from the Centre for Ecology & Hydrology, © NERC (CEH). © Crown Copyright and Database Rights 2025 OS AC0000807064. This product is produced in part from PAF® and Multiple Residence Data, the copyright in which is owned by Royal Mail Group Limited and/or Royal Mail Group plc. All rights reserved. Licence number AC0000807064.