Does SM3 flood?

Yes — parts of the SM3 district carry real flood risk: 5 of its 17 at-risk postcodes reach the Environment Agency's High likelihood band. The SM3 postcode district covers Stonecot, North Cheam, close to Morden, Worcester Park, New Malden, and surrounding villages in parts of Greater London and Surrey.

17 postcodes in the SM3 district appear in the Environment Agency's rivers-and-sea flood-risk dataset — worst bands: 5 high, 2 medium, 10 low. A postcode not listed here has no properties in any recorded risk band (which is good news, but never proof it cannot flood).

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Which SM3 postcodes are at risk?

SM3 9DT up to High SM3 9QL up to High SM3 9QN up to High SM3 9RE up to High SM3 9RL up to High SM3 9EA up to Medium SM3 9RH up to Medium SM3 9BJ up to Low SM3 9DR up to Low SM3 9EB up to Low SM3 9HX up to Low SM3 9QJ up to Low SM3 9QQ up to Low SM3 9QZ up to Low SM3 9RA up to Low SM3 9RJ up to Low SM3 9RN up to Low

Rivers and flooding history near SM3

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

North Cheam on the Pyl Brook — 0.4 km away, highest on record 2.92m
Morden Park on the Pyl Brook — 1.6 km away, highest on record 2.40m
Worcester Park on the Beverley Brook — 2.1 km away, highest on record 2.85m
Kings College on the Pyl Brook — 2.6 km away, highest on record 2.52m

461 official flood warnings and alerts have been raised within ~10 km of the district's centre since 2006 (25 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):

September 1968 flooding — about 1 km from the centre

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

🏠 Buying or renting in SM3? 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

SM4 SM1 SM5 SM6

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.