Does GU20 flood?

Yes — parts of the GU20 district carry real flood risk: 8 of its 12 at-risk postcodes reach the Environment Agency's High likelihood band. The GU20 postcode district covers Windlesham & Chobham, Bagshot, close to Chobham, Virginia Water, Blackwater, and surrounding villages in parts of Surrey and Hampshire.

12 postcodes in the GU20 district appear in the Environment Agency's rivers-and-sea flood-risk dataset — worst bands: 8 high, 1 medium, 3 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 GU20 postcodes are at risk?

GU20 6AF up to High GU20 6BX up to High GU20 6DJ up to High GU20 6EP up to High GU20 6ET up to High GU20 6EX up to High GU20 6HD up to High GU20 6HE up to High GU20 6BY up to Medium GU20 6HP up to Low GU20 6JF up to Low GU20 6LQ up to Low

Rivers and flooding history near GU20

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

Bagshot on the Windle Brook — 2.5 km away, highest on record 1.65m
Millbourne Bridge on the Mill Bourne — 4 km away, highest on record 2.73m
Grants Bridge on the Addlestone Bourne — 4.2 km away, highest on record 2.50m
Trumps Green on the Chertsey Bourne — 7.4 km away, highest on record 2.07m

200 official flood warnings and alerts have been raised within ~10 km of the district's centre since 2006 (3 at warning level or above), most recently 14 March 2026. Warnings cover flood areas, not individual addresses.

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

Winter 2013/2014 (2013) — about 12.9 km from the centre
06JanuaryNewYear2003 (2002) — about 3.1 km from the centre
September 1968 flooding — about 5.6 km from the centre

🏠 Buying or renting in GU20? 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

GU19 GU21 GU18 GU22 GU17 GU23 GU16 GU24

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.