Dorset Flood Risk
In Dorset, 4,603 of 249,144 properties (1.8%) 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 28th of 296 local authorities in England by number.
By bandProperties in Dorset 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 | 2,857 | 1,516 |
| Medium | between 1% and 3.3% (1 in 100 to 1 in 30) chance in any year | 1,746 | 1,159 |
| Low | between 0.1% and 1% (1 in 1,000 to 1 in 100) chance in any year | 7,229 | 5,064 |
| Very low | less than 0.1% (1 in 1,000) chance in any year | 1,853 | 1,428 |
2,675 of the high- or medium-risk properties are homes and 1,331 are non-residential. 868 postcodes in Dorset have at least one property at high or medium risk.
Postcode districtsFlood risk across Dorset
Counts are for the part of each district inside Dorset.
| District | Properties | High + medium | High | Share |
|---|---|---|---|---|
| DT4 | 23,148 | 522 | 211 | 2.3% |
| DT3 | 15,959 | 508 | 391 | 3.2% |
| DT2 | 20,397 | 492 | 330 | 2.4% |
| DT6 | 18,043 | 464 | 271 | 2.6% |
| DT11 | 19,290 | 427 | 219 | 2.2% |
| BH21 | 22,900 | 407 | 113 | 1.8% |
| BH19 | 9,265 | 351 | 305 | 3.8% |
| DT5 | 7,804 | 276 | 262 | 3.5% |
| BH22 | 14,788 | 232 | 194 | 1.6% |
| SP8 | 9,290 | 209 | 103 | 2.2% |
| BH20 | 13,541 | 152 | 128 | 1.1% |
| DT9 | 12,219 | 124 | 72 | 1.0% |
| DT7 | 3,227 | 118 | 74 | 3.7% |
| DT8 | 4,777 | 105 | 31 | 2.2% |
| DT10 | 8,573 | 44 | 24 | 0.5% |
| DT1 | 13,168 | 42 | 27 | 0.3% |
| BH24 | 4,986 | 39 | 37 | 0.8% |
| SP7 | 8,842 | 36 | 27 | 0.4% |
| BH13 | 52 | 21 | 21 | 40.4% |
| BH31 | 6,742 | 7 | 5 | 0.1% |
| BA22 | 509 | 7 | 2 | 1.4% |
| TA18 | 29 | 5 | 2 | 17.2% |
| BH16 | 7,454 | 3 | 2 | 0.0% |
| EX13 | 50 | 3 | 3 | 6.0% |
| BH15 | 26 | 3 | 1 | 11.5% |
| SP6 | 1,719 | 2 | 0 | 0.1% |
| BA21 | 10 | 2 | 1 | 20.0% |
| SP5 | 1,422 | 1 | 1 | 0.1% |
| TA20 | 692 | 1 | 0 | 0.1% |
| BH18 | 222 | 0 | 0 | 0.0% |
Recorded floodsPast floods mapped in Dorset
The Environment Agency has mapped flood outlines on 116 dates in postcode districts that mostly lie in Dorset since 1824; the most recent started on 21 Oct 2021.
1820s 1 1890s 2 1950s 2 1960s 2 1970s 5 1980s 4 1990s 40 2000s 28 2010s 31 2020s 1
| Started | Place / name in the record | Source of flooding | Cause | Districts |
|---|---|---|---|---|
| 21 Oct 2021 – 22 Oct 2021 | Gillingham 8 outlines | Main river | Channel capacity exceeded (no raised defences) | BH21 DT10 DT11 SP8 |
| 24 Dec 2014 | Maiden Newton to | Main river | Channel capacity exceeded (no raised defences) | DT2 |
| 20 Feb 2014 | Milborne St Andrew to | Main river | Channel capacity exceeded (no raised defences) | DT11 |
| 19 Feb 2014 | This represents flooding in the area in | Drainage | Local drainage/surface water | BH22 |
| 18 Feb 2014 | Winterborne Clenston to | Main river | Groundwater/high water table | DT11 |
| 17 Feb 2014 | This represents flooding in the area in | Not recorded | Not recorded | DT7 |
| 14 Feb 2014 | This represents flooding in the area in | Drainage | Local drainage/surface water | BH31 |
| 7 Feb 2014 | Wareham to | Main river | Channel capacity exceeded (no raised defences) | BH20 |
| 5 Feb 2014 | Chiswell to 3 outlines | Sea | Overtopping of defences | BH19 DT5 |
| 23 Jan 2014 | Mere to 2 outlines | Main river | Channel capacity exceeded (no raised defences) | DT8 SP8 |
| 9 Jan 2014 – 27 Feb 2014 | Flood Extents to 11 outlines | Main river | Channel capacity exceeded (no raised defences) | BH16 BH20 BH21 BH22 DT1 DT10 DT11 DT2 |
| 8 Jan 2014 | This represents flooding in the area in | Drainage | Local drainage/surface water | DT7 |
| 7 Jan 2014 | Wimborne Minster to 2 outlines | Main river, ordinary watercourse | Channel capacity exceeded (no raised defences) | BH21 DT1 |
| 6 Jan 2014 | Chiswell to 4 outlines | Sea, main river | Channel capacity exceeded (no raised defences) | BH31 DT2 DT5 |
| 5 Jan 2014 | Charminster to 3 outlines | Main river, sea | Channel capacity exceeded (no raised defences) | DT2 DT5 DT8 |
| 4 Jan 2014 – 17 Feb 2014 | This represents flooding in the area in 4 outlines | Main river, drainage | Channel capacity exceeded (no raised defences) | BH21 DT2 DT6 DT8 |
| 2 Jan 2014 | This represents flooding in the area in | Main river | Local drainage/surface water | DT9 |
| 1 Jan 2014 | Spetisbury to 2 outlines | Main river, ordinary watercourse | Channel capacity exceeded (no raised defences) | DT11 SP7 |
| 30 Dec 2013 | This represents flooding in the area in | Drainage | Local drainage/surface water | BH22 |
| 25 Dec 2013 | West Moors, Ferndown to | Main river | Channel capacity exceeded (no raised defences) | BH22 |
| 24 Dec 2013 – 28 Mar 2014 | Donhead St Andrew to 8 outlines | Main river, ordinary watercourse | Channel capacity exceeded (no raised defences) | BH21 BH22 DT10 DT11 SP7 |
| 23 Dec 2013 | This represents flooding in the area in 5 outlines | Ordinary watercourse, main river | Channel capacity exceeded (no raised defences) | BH21 BH31 DT9 |
| 10 Feb 2013 | This represents flooding in the area in 2 outlines | Drainage | Local drainage/surface water | DT6 |
| 27 Jan 2013 | This represents flooding in this area | Drainage | Local drainage/surface water | DT7 |
| 24 Jan 2013 | This represents flooding in the area in | Sewer | Other | DT6 |
| 22 Dec 2012 | This represents flooding in the area in | Drainage | Local drainage/surface water | BH31 |
| 24 Nov 2012 | This represents flooding in the area in 2 outlines | Not recorded | Not recorded | DT6 |
| 7 Nov 2012 | This represents flooding in the area in | Main river | Channel capacity exceeded (no raised defences) | DT7 |
| 1 Nov 2012 | This represents flooding in the area in | Not recorded | Not recorded | DT7 |
| 7 Jul 2012 – 24 Nov 2012 | This represents flooding in the area in 21 outlines | Ordinary watercourse, other | Other | DT1 DT3 DT6 DT7 DT8 DT9 |
| 6 Jul 2012 – 7 Jul 2012 | This represents flooding in the area in | Drainage | Other | DT6 |
| 1 Jul 2012 | This represents flooding in the area in 3 outlines | Not recorded | Not recorded | DT1 DT7 |
| 11 Feb 2009 | Stour Flood 71 outlines | Main river | Channel capacity exceeded (no raised defences) | BH21 DT11 |
| 10 Feb 2009 | This represents flooding in the area in 2 outlines | Main river | Not recorded | BH22 BH31 |
| 6 Feb 2009 | This represents flooding in the area in | Ordinary watercourse | Other | BH31 |
| 1 Jan 2009 | This represents flooding in the area in | Ordinary watercourse | Channel capacity exceeded (no raised defences) | DT6 |
| 13 Dec 2008 | This represents flooding in the area in | Main river | Not recorded | DT8 |
| 12 Sep 2008 | This represents flooding in the area in 5 outlines | Main river, ordinary watercourse | Not recorded | DT8 |
| 15 Dec 2007 | This represents flooding in the area in | Ordinary watercourse | Channel capacity exceeded (no raised defences) | DT6 |
| 8 Dec 2007 | This represents flooding in the area in | Ordinary watercourse | Channel capacity exceeded (no raised defences) | DT6 |
Showing the 40 most recent of 116 dates.
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.
"Dorset" means the local authority area (ONS code E06000059), not only the town centre.
If you live in Dorset
- 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 Dorset at risk of flooding?
In Dorset, 4,603 of 249,144 properties (1.8%) 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 28th of 296 local authorities in England by number.
Which parts of Dorset have the most properties at flood risk?
Postcode district DT4 has the most: 522 properties at high or medium risk (2.3% of its properties in Dorset). The table on this page lists every district.
When did Dorset last flood?
The Environment Agency has mapped flood outlines on 116 dates in postcode districts that mostly lie in Dorset since 1824; the most recent started on 21 Oct 2021.
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.