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Does Blackwater flood? 41 postcodes in Blackwater are in the Environment Agency's rivers-and-sea flood-risk data (30 High likelihood) — the breakdown is further down this page.
No official flood warning is active nearby and the closest river stations are within normal ranges.
Updated 2026-10-09 15:12:16 UTC · Official GOV.UK warnings · Flood preparation & help guide
Blackwater is a town in the Hart District of Hampshire, England. It forms part of the Farnborough/Aldershot Built-up Area and almost is contiguous with Camberley, and situated 32 miles (51 km) west-southwest of London.
Ordnance Survey places 41 postcodes in Blackwater in the Environment Agency's rivers-and-sea flood-risk dataset (Risk of Flooding from Rivers and Sea). Each postcode is counted once, under the worst band any of its properties reaches; together they hold 300 properties in the EA dataset's likelihood bands.
| EA likelihood band | Postcodes (worst band) | Properties in the EA dataset | of which homes |
|---|---|---|---|
| High | 30 | 159 | 144 |
| Medium | 0 | 8 | 8 |
| Low | 11 | 133 | 127 |
| Very low | 0 | 0 | 0 |
| All bands | 41 | 300 | 279 |
This dataset covers flooding from rivers and the sea only — one of five flood sources. Surface water, groundwater, sewers and reservoirs are assessed separately, so a postcode missing from it is not proof that a place cannot flood. The band describes the land around properties (allowing for defences), not any single address and not today's conditions.
Camberley · Sandhurst · Frimley · Farnborough · Yateley · Crowthorne · Ash Vale · Bracknell
Flood-risk bands: © 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.
Place names: Contains OS data © Crown copyright and database rights 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Contains National Statistics data © Crown copyright and database right 2026. Licensed under the Open Government Licence v3.0.
The nearest watercourse on the river map is Blackwater River, about 60 m from the middle of Blackwater's gauges. It flows into the River Loddon about 18 km downstream.
A gauge downstream shows water that has already passed this point; one upstream sees it first. Distances along the river are from the point on Blackwater River nearest the middle of Blackwater's gauges. From Ordnance Survey’s river map (OS Open Rivers), which leaves out small streams, ditches and culverts, so a nearer one may exist. This describes where water goes on the map; it says nothing about flooding at any address. Contains OS data © Crown copyright and database rights 2026.
Blackwater is monitored by 1 Environment Agency river level station on the River Blackwater, in Hampshire. Water levels are updated every 15 minutes, providing real-time flood monitoring for the area.
The River Blackwater is monitored by 1 station (Blackwater Bridge). Each station records water levels continuously, with data synced to FloodRadar every 5 minutes.
There are 8 Environment Agency flood warning areas within 10km of Blackwater. When the EA issues a flood warning for any of these areas, it will appear on this page. These include: Cove Brook at Farnborough including Hawley Bridge, Hampshire; Cove Brook at West Farnborough including West Heath and Rafborough; River Blackwater including Badshot Lea, Aldershot, Farnborough, Camberley, Sandhurst, Eversley, Bramshill and Swallowfield, and the Cove Brook at Farnborough and Cove; River Blackwater at Camberley and Sandhurst including Frimley Business Park, Shepherd Meadows Nature Reserve and Trilakes Country Park, Surrey and Berkshire.
There are 3 storm overflows within 5km of Blackwater. None of the 3 with a reporting monitor are currently discharging. Enable "Sewage" on the map above to see their locations.
Each has its own page of live status and past discharges:
If flooding is forecast in Blackwater, call Floodline on 0345 988 1188 for the latest information. Move valuables upstairs, turn off gas and electricity if safe to do so, and avoid walking or driving through flood water. Sign up for flood warnings on any station page above to receive email alerts when water levels rise. For emergency numbers, a preparation checklist and insurance guidance, see our flood help & preparation guide.
Blackwater gets about 729 mm of rain a year on average (wettest month November, 83 mm; driest March, 47 mm). That is 37% drier than the UK as a whole, which averages 1,163 mm a year. See the rain gauges →
A thirty-year average for the area, not a forecast and not a flood risk on its own. Source: Met Office HadUK-Grid 1991–2020 (5 km grid), 3.2 km away. Average rainfall: HadUK-Grid v1.3.2, Met Office. Contains public sector information licensed under the Open Government Licence v3.0.
Floods whose mapped extent (EA Recorded Flood Outlines) reached within ~5 km of the town centre — most recent first. These are records of mapped extents, not a full list of floods. See them on the map →
Records, not floods: no outline on the record is not evidence a place has not flooded.
Current verdict: Normal. No official flood warning is active nearby and the closest river stations are within normal ranges.
Blackwater has river level monitoring on River Blackwater — 1 monitoring station in total.
Use the GOV.UK Check for Flooding service (check-for-flooding.service.gov.uk) or call Floodline on 0345 988 1188 (24 hours). You can also set up free FloodRadar email or browser alerts from any station page above.
Follow official advice: move valuables and vehicles to safety, never walk or drive through flood water, turn off gas and electricity if safe, and check on vulnerable neighbours. See our flood preparation guide at floodradar.co.uk/flood-help.
Yes — the Environment Agency's Recorded Flood Outlines dataset shows 5 recorded flood extents around the town centre since 1703, most recently in 1990. That is a count of mapped extents, not of separate floods. Records, not floods: no outline on the record is not evidence a place has not flooded. See the flood history link below.
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