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Does Marchwood flood?

Hampshire
42postcodes in the EA rivers-and-sea dataset
7river gauges within 10 km
5tidal gauges within 10 km
3years with a mapped flood record within 5 km
🏠 Thinking of buying in Marchwood? Get the detailed Property Flood-Risk Report for any Marchwood postcode — official risk band, recorded floods since 1703, warning history, river behaviour and nearby storm overflows. £19 one-off, instant. Learn more →

Flood warnings in force near Marchwood

From the Environment Agency (England). Always check the GOV.UK Check for Flooding service or call Floodline on 0345 988 1188.

What the Environment Agency's rivers-and-sea flood-risk data says about Marchwood

Ordnance Survey places 42 postcodes in Marchwood 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 412 properties in the EA dataset's likelihood bands.

EA likelihood bandPostcodes (worst band)Properties in the EA datasetof which homes
High165028
Medium10115103
Low14165136
Very low28273
All bands42412340

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.

Rivers and live river levels near Marchwood

Environment Agency gauges within 10 km of Marchwood watch Tanners Brook, Bartley Water, River Test, River Itchen, Beaulieu River, Monks Brook.

Distances are from the middle of Marchwood's at-risk postcodes. Tidal and structure gauges are shown as readings only — the tide and sluice gates move them, not floods. A gauge with no recent reading shows no level.

The watercourse nearest Marchwood

The nearest watercourse on the river map is Cracknore Hard Stream, about 310 m from the middle of Marchwood's at-risk postcodes. It flows into the River Test about 2.2 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 Cracknore Hard Stream nearest the middle of Marchwood's at-risk postcodes. 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.

Flood warning areas near Marchwood

13 Environment Agency flood warning areas lie within 10 km of Marchwood. The EA has issued 268 flood warnings and alerts for them since 2006, most recently on 25 Oct 2026.

Recorded floods near Marchwood

Floods whose mapped extent (EA Recorded Flood Outlines) reached within ~5 km of Marchwood, most recent first. Records, not floods: no outline on the record is not evidence a place has not flooded. See them on the map →

…and 12 earlier recorded floods on the map.

Rainfall near Marchwood

Marchwood gets about 863 mm of rain a year on average (wettest month November, 105 mm; driest July, 48 mm). That is 26% drier than the UK as a whole, which averages 1,163 mm a year. Source: Met Office HadUK-Grid 1991–2020 (5 km grid), 2.1 km from the place centre.

The nearest rain gauge, Rainfall station (8.1 km away), recorded 9.3 mm in the last 24 hours and 100.7 mm in the last 7 days (latest reading 28 min ago).

At-risk postcodes in Marchwood

Every postcode Ordnance Survey places in Marchwood that appears in the EA's rivers-and-sea dataset, worst band first. Each links to its own flood-risk page.

High likelihood (16)

SO40 4AFSO40 4AHSO40 4ARSO40 4AUSO40 4BDSO40 4BESO40 4BLSO40 4LBSO40 4SDSO40 4SYSO40 4UXSO40 4WTSO40 4XESO40 4XGSO40 4XSSO40 4ZD

Medium likelihood (10)

SO40 4ADSO40 4ALSO40 4AQSO40 4ASSO40 4AWSO40 4AXSO40 4BXSO40 4LESO40 4SQSO40 4UY

Low likelihood (14)

SO40 4AGSO40 4AJSO40 4ANSO40 4APSO40 4ATSO40 4BJSO40 4JXSO40 4SESO40 4UBSO40 4WHSO40 4XRSO40 4XTSO40 4XUSO40 4YR

Very low likelihood (2)

SO40 4AASO40 4AB

Postcode districts

SO40 · 42

Sources

FloodRadar summarises public flood data. It is not a flood-risk survey of any property, and it does not replace official GOV.UK flood warnings or the GOV.UK long-term flood risk service.

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.

Recorded Flood Outlines, flood warning areas and warning history © Environment Agency copyright and/or database right 2025. Licensed under the Open Government Licence v3.0.

River levels and rainfall: Environment Agency real-time flood-monitoring data, updated every 15 minutes (Open Government Licence v3.0).

Average rainfall: HadUK-Grid v1.3.2, Met Office. Contains public sector information licensed under the Open Government Licence v3.0.

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.

All data sources & licences