Test Valley Flood Risk
In Test Valley, 1,118 of 73,066 properties (1.5%) are in areas at high or medium risk of flooding from rivers and the sea — at least a 1 in 100 chance in any year — per Environment Agency data updated 6 July 2026; that ranks 165th of 296 local authorities in England by number.
By bandProperties in Test Valley by flood-risk band
| Risk band | Chance of flooding each year | All properties | Homes |
|---|---|---|---|
| High | 3.3% (1 in 30) or greater chance in any year | 667 | 444 |
| Medium | between 1% and 3.3% (1 in 100 to 1 in 30) chance in any year | 451 | 305 |
| Low | between 0.1% and 1% (1 in 1,000 to 1 in 100) chance in any year | 1,135 | 900 |
| Very low | less than 0.1% (1 in 1,000) chance in any year | 54 | 38 |
749 of the high- or medium-risk properties are homes and 248 are non-residential. 194 postcodes in Test Valley have at least one property at high or medium risk.
Postcode districtsFlood risk across Test Valley
Counts are for the part of each district inside Test Valley.
Recorded floodsPast floods mapped in Test Valley
The Environment Agency has mapped flood outlines on 19 dates in postcode districts that mostly lie in Test Valley since 1995; the most recent started on 28 Feb 2014.
1990s 5 2000s 6 2010s 8
| Started | Place / name in the record | Source of flooding | Cause | Districts |
|---|---|---|---|---|
| 28 Feb 2014 | River Test Photography 5 outlines | Other | Groundwater/high water table | SO20 SO51 SP10 |
| 21 Feb 2014 | Chilbolton | Ordinary watercourse | Groundwater/high water table | SP10 |
| 16 Feb 2014 | World of Water, Romsey 15 outlines | Main river, other | Groundwater/high water table | SO51 SP11 |
| 14 Feb 2014 | Little Somborne 5 outlines | Ordinary watercourse, main river | Groundwater/high water table | SO20 SP11 |
| 13 Feb 2014 | Bransbury | Main river | Groundwater/high water table | SP10 |
| 9 Feb 2014 | Greatbridge Road by Railway 2 outlines | Main river | Groundwater/high water table | SO51 |
| 8 Feb 2014 | Budds Lane, Romsey 6 outlines | Main river | Groundwater/high water table | SO51 |
| 7 Feb 2014 | Greatbridge Road South, Romsey 3 outlines | Main river | Groundwater/high water table | SO51 |
| 1 Dec 2002 – 1 Mar 2003 | Charlton River 363 outlines | Ephemeral watercourse | Groundwater/high water table | SP10 SP11 |
| 1 Jan 2001 – 1 Apr 2001 | River Dun West Tytherley 6 outlines | Ephemeral watercourse | Groundwater/high water table | SO20 |
| 1 Dec 2000 – 1 May 2001 | Sombourne St King's Somborne 25 outlines | Ephemeral watercourse, main river | Groundwater/high water table | SO20 SO51 SP10 SP11 |
| 1 Nov 2000 – 1 May 2001 | River Test Braishfield 8 outlines | Ephemeral watercourse, main river | Groundwater/high water table | SO20 SO51 SP11 |
| 1 Oct 2000 – 1 May 2001 | Pilhill Brook Monxton 2 outlines | Main river | Groundwater/high water table | SP11 |
| 11 May 2000 | River Anton Upper Clatford | Not recorded | Not recorded | SP10 |
| 24 Dec 1999 | Tadburn Lake Romsey | Not recorded | Not recorded | SO51 |
| 13 Feb 1995 – 6 Mar 1995 | Upper Test Wherwell 4 outlines | Main river | Channel capacity exceeded (no raised defences) | SP10 |
| 1 Feb 1995 – 27 Apr 1995 | Sombourne Stream Kings Somborne 11 outlines | Ephemeral watercourse | Groundwater/high water table | SO20 SP11 |
| 30 Jan 1995 – 17 Apr 1995 | Wallop Brook Nether Wallop | Main river | Groundwater/high water table | SO20 |
| 1 Jan 1995 – 1 Apr 1995 | Lower Test 384 outlines | Ephemeral watercourse, other | Groundwater/high water table | SO20 SO51 SO52 SP10 SP11 |
What this page shows, and what it misses
The Environment Agency's count of properties in each postcode that sit in areas of land at very low, low, medium or high risk of flooding from rivers and the sea, allowing for flood defences and their condition, added up here by postcode district and local authority. Every property in England is counted once, so the share is of all properties in the area.
It misses: surface water (heavy rain), groundwater, sewer and reservoir flooding; Wales, Scotland and Northern Ireland; and anything about a single building. A band describes the land a property stands on, not its floor level or flood protection, so it is not a forecast for any one home. Past floods come from the EA's Recorded Flood Outlines and are placed in the postcode district whose centre is nearest (within 12 km), so a flood near a boundary can be listed under a neighbour. Older records are patchy, and a flood with no outline is not listed.
"Test Valley" means the local authority area (ONS code E07000093), not only the town centre.
If you live in Test Valley
- Check your own address on gov.uk; it also covers surface water.
- Sign up for free flood warnings: gov.uk/get-flood-warnings. Floodline: 0345 988 1188.
- What is in force now: flood warnings UK · river levels.
- Never walk or drive through flood water: why shallow water kills.
FAQQuestions people ask
Is Test Valley at risk of flooding?
In Test Valley, 1,118 of 73,066 properties (1.5%) are in areas at high or medium risk of flooding from rivers and the sea — at least a 1 in 100 chance in any year — per Environment Agency data updated 6 July 2026; that ranks 165th of 296 local authorities in England by number.
Which parts of Test Valley have the most properties at flood risk?
Postcode district SO51 has the most: 572 properties at high or medium risk (3.1% of its properties in Test Valley). The table on this page lists every district.
When did Test Valley last flood?
The Environment Agency has mapped flood outlines on 19 dates in postcode districts that mostly lie in Test Valley since 1995; the most recent started on 28 Feb 2014.
Does this include surface water flooding?
No. These counts cover flooding from rivers and the sea only. Surface water (heavy rain) flooding affects more properties in England; check it for one address on gov.uk's long-term flood risk service.
Flood risk counts: Environment Agency, Risk of Flooding from Rivers and Sea – Postcodes in Areas at Risk and Recorded Flood Outlines, used under the Open Government Licence v3.0. © Environment Agency copyright and/or database right 2025. All rights reserved. Some features of this information 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.
Local authority of each postcode: Office for National Statistics postcode lookup (May 2026), licensed under the Open Government Licence v3.0. Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. District centres and place names: postcodes.io (ONS/OS open data). Totals, ranks and grouping are Global Incident Tracker's own calculations; the Environment Agency does not endorse them.