Does SO17 flood?

Yes — parts of the SO17 district carry real flood risk: 15 of its 25 at-risk postcodes reach the Environment Agency's High likelihood band. The SO17 postcode district covers Portswood, Swaythling, close to Woolston, Southampton, Millbrook, and surrounding villages in parts of Hampshire and England.

25 postcodes in the SO17 district appear in the Environment Agency's rivers-and-sea flood-risk dataset — worst bands: 15 high, 4 medium, 4 low, 2 very 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 SO17 postcodes are at risk?

Rivers and flooding history near SO17

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

Riverside Park on the River Itchen — 1.6 km away, highest on record 2.19m
Stoneham Lane on the Monks Brook — 3.4 km away, highest on record 1.01m
STONEHAM LANE GS — 3.5 km away
Shirley Pond on the Tanners Brook — 3.9 km away, highest on record 14.43m

392 official flood warnings and alerts have been raised within ~10 km of the district's centre since 2006 (94 at warning level or above), most recently 19 February 2026. Warnings cover flood areas, not individual addresses.

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

Winter 13/14 East Hampshire Aerial Photography (2014) — about 16.1 km from the centre
10/03/2008 Priory Road (2008) — about 0.5 km from the centre
10/03/2008 Woodmill (2008) — about 1.2 km from the centre
10/03/2008 Riverside Park (2008) — about 0.4 km from the centre

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

🏠 Buying or renting in SO17? 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

SO16 SO18 SO15 SO19 SO14 SO20 SO21 SO22

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.