Photo: Richard Humphrey · CC BY-SA 2.012% of Keswick’s homes are at high or medium risk from rivers or the sea, more than in 96% of UK towns
On the Environment Agency’s maps, which allow for flood defences, “high or medium” means at least a 1 in 100 chance of flooding from rivers or the sea in any year. Hazard risk puts Keswick at D−.
What stands out about Keswick’s hazards
From the Environment Agency’s maps and records and the BGS radon atlas, below.
What Keswick faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Rivers and the sea
Surface water
Past floods
The River Derwent
Flood warnings
Radon
Keswick grades D− for hazard risk
Flood risk from rivers and the sea, against all UK towns.
The share of homes at high or medium risk from rivers and the sea, ranked against every UK town of 1,000 or more: fewer homes at risk is better. Towns with none at high or medium risk are ordered by their share at low risk, so they don’t all share one score. Surface water and radon aren’t graded: they are described below.
Where the water goes in Keswick
Turn layers on and off. Blue is the risk from rivers and the sea; pink is where heavy rain collects. Both allow for flood defences.
The river and sea risk follows the River Greta, the St Johns Beck and the Glendermackin. Surface-water risk is patchier: dips, underpasses and small streams.
12% of Keswick’s homes are at high or medium risk from rivers or the sea
The Environment Agency’s national map, allowing for defences. A further 5.6% are at low risk.
Share of each UK town’s homes at high or medium risk from rivers and the sea. 35% of UK towns have none; Keswick has more than 96% of towns.
| # | Town | People | High or med. | |
|---|---|---|---|---|
| 1 | Finningley South Yorkshire | 5,919 | 0% | |
| 2 | Leiston Suffolk | 5,919 | 0% | |
| 3 | West Hallam Derbyshire | 5,912 | 0% | |
| … | ||||
| 658 | Cross Hills North Yorkshire | 4,809 | 12% | |
| 659 | Lostwithiel Cornwall | 3,067 | 12% | |
| 660 | Keswick Cumbria | 4,465 | 12% | |
| 661 | Whalley Lancashire | 3,411 | 12% | |
| 662 | Wilton Wiltshire | 4,300 | 12% | |
| … | ||||
| 694 | Chapel St Leonards Lincolnshire | 3,435 | 66% | |
| 695 | Gilberdyke East Riding of Yorkshire | 3,028 | 70% | |
UK towns of 3,000 to 6,000 people.
The Environment Agency’s Risk of Flooding from Rivers and Sea (NaFRA2, June 2026) counts each postcode’s homes by band; the shares weight those postcodes by Census 2021 households. The EA counts include homes built since 2021.
Rivers and the sea, more than heavy rain, are Keswick’s flood risk
Surface water is rain that falls faster than drains and the ground can take it. It is mapped separately from rivers and the sea, and it is not in the Hazard risk Grade.
About 5.1% of homes are at high risk of surface-water flooding (a 1 in 30 chance or more each year) and 3.1% at medium risk: roughly 180 households. A further 8.1% face a low risk from surface water. That is more than 88% of UK towns.
Our estimate: every address in the town (ONS NSUL) read on the Environment Agency’s Risk of Flooding from Surface Water map (NaFRA2, 2025), each postcode’s share weighted by its Census 2021 households. Neither agency publishes a count of homes for surface water, so treat it as a guide; one street can differ from the next.
Keswick has flooded in 9 recorded years since 1977, most of all in 2015
Every flood the Environment Agency has mapped inside Keswick’s built-up area, newest first. The record is fullest for big river floods; small and surface-water floods are often missing.
- 2021October 2021: River flooding recorded2 hectares inside today’s built-up area
- 2020February 2020: River flooding recorded4 hectares inside today’s built-up area
- 2015December 2015: River flooding recorded59 hectares inside today’s built-up area
- 2009November 2009: River flooding recorded37 hectares inside today’s built-up area · Keswick flooding
- 2008October 2008: River flooding recorded1 hectare inside today’s built-up area · Keswick Campsite & Rugby Club
- 2005January 2005: River flooding recorded34 hectares inside today’s built-up area
Show all 9
- 1999November 1999: River flooding recorded2 hectares inside today’s built-up area
- 1985December 1985: The sea came in29 hectares inside today’s built-up area
- 1977October 1977: River flooding recorded10 hectares inside today’s built-up area
Floodwater covered 59 hectares of what is now Keswick in 2015, the largest flood the record holds here (December).
514 of Keswick’s households today live inside the outline of a recorded flood.
Since 2015, the largest recorded flood inside the town covered 4 hectares.
The River Derwent at Portinscale: highest 4.27 m, in November 2009
The highest level each winter (October to September) at the Environment Agency’s Portinscale gauge (Portinscale), since 1990. The river normally runs between 0.31 m and 1.33 m here.
- 19 November 20094.27 m
- 8 January 20053.33 m
- 31 January 19952.93 m
- 5 December 20152.92 m
- 26 October 20082.88 m
- 28 October 20212.81 m
The River Derwent has topped its normal range on 1,070 days since 1990, most in the winters of 1999–00 and 2023–24. By its highest day, the winter of 2025–26 was the 10th-highest of the 32.
Environment Agency Hydrology API, Portinscale (station 751007), daily maximum level; the record and normal range from the EA’s stage scale. Live river levels are on GOV.UK’s Check for flooding.
No flood warning or alert is in force for Keswick · 190 warnings in 20 years
The Environment Agency has 11 flood warning areas and 2 alert areas reaching into the town; warnings since the service began in 2006.
Of the 190 warnings, 112 were for Keswick Campsite and 43 for River Greta at Keswick, Keswick Campsite, Rugby Club and Quinta. 2015 had the most warnings (34); 2008 the most alerts (34).
The most recent warning was on 26 February 2026.
Show the 13 warning and alert areas
| Area | Kind | Since 2006 | Now |
|---|---|---|---|
| Keswick Campsite | Warning area | 112 | None |
| River Greta at Keswick, Keswick Campsite, Rugby Club and Quinta | Warning area | 43 | None |
| River Greta at Keswick, Fitz Park and Riverside Flats areas | Warning area | 18 | None |
| Elliot Park at Keswick | Warning area | 4 | None |
| River Greta at Keswick, Elliot Park, Main Street and Pencil Works area | Warning area | 3 | None |
| River Greta at Keswick, Crosthwaite Road, Limepots Road, High Hill and Church Lane areas | Warning area | 3 | None |
| River Greta at Keswick, Main Street, Bank Street and Greta Side | Warning area | 2 | None |
| River Greta at Keswick, Penrith Road and Wordsworth Street | Warning area | 2 | None |
| Greta Street and Penrith Road at Keswick | Warning area | 1 | None |
| River Greta at Keswick, The Forge area | Warning area | 1 | None |
| River Greta at Keswick, Lattrigg Close, Brundholme Gardens, Calvert's Bridge and Keswick Bridge | Warning area | 1 | None |
| Upper River Derwent, Stonethwaite Beck and Derwent Water | Alert area | 206 | None |
| Rivers Greta, St Johns Beck and Bassenthwaite Lake | Alert area | 112 | None |
Environment Agency Historic Flood Warnings (first issues only, not updates; “flood watch” counted as an alert before 2011) and the real-time flood-monitoring API. Sign up for free warnings on GOV.UK or call Floodline, 0345 988 1188.
Parts of Keswick are in radon Affected Areas, at the low end
Radon is a natural radioactive gas from the ground; long exposure raises the risk of lung cancer. The atlas gives the chance that a home in each 1 km square is above the UK action level (200 Bq/m³).
6% of Keswick’s built-up area is in a radon Affected Area (1% of homes or more above the action level).
The squares are indicative: each takes the highest band found anywhere inside it, so most homes in a coloured square are below it. Only a three-month test in the home gives a real answer.
BGS/UKHSA Indicative Atlas of Radon in Great Britain, version 3. Check an address at UKradon.org.
Flood risk in the places around Keswick
Share of homes at high or medium and at low risk from rivers and the sea. Tap a town for its page.
| Town | People | High or medium | Low | Hazard |
|---|---|---|---|---|
| Keswick | 4,465 | 12% | 5.6% | D− |
| Cockermouth | 8,859 | 10% | 5.7% | D− |
Keswick has more homes at high or medium risk than any neighbour in the table.
Get ready for what Keswick faces
Free warnings, what to do in a cloudburst, and what to check before you move.
- Sign up free for Environment Agency flood warnings by text, call or email.
- Floodline: 0345 988 1188, 24 hours.
- Keswick’s warning areas include River Greta at Keswick, Crosthwaite Road, Limepots Road, High Hill and Church Lane areas and River Greta at Keswick, Fitz Park and Riverside Flats areas.
- Surface water rises in minutes, often with no warning issued: stay out of underpasses and dips.
- Keep the gullies and drains outside your home clear of leaves.
- Report a blocked road drain to the council.
- Test over three months, in a living room and a bedroom.
- Above 200 Bq/m³, a small sump and fan usually fixes it.
- New homes in radon areas are built with protection: basic from 3%, full from 10%.
- Check the address on GOV.UK’s long-term flood risk service: it gives rivers and sea and surface water separately.
- Ask whether the home has flooded or had a flood insurance claim; the TA6 property form asks the seller.
- Homes built before 2009 can get flood cover through Flood Re, the government-backed scheme; newer homes can’t.
- Check radon for the address on UKradon.org (a small fee) or ask the seller for a test result.
What this data can and can’t tell you
- Defences are counted. Both agencies’ maps allow for flood defences and the chance they are overtopped or fail, so a town behind a defence scheme can show few homes at high risk and many at low risk.
- Surface water is our estimate. Neither agency publishes a count of homes at risk from surface water, so we read each address on the map. A flat on a hill and a basement in a dip can share a postcode.
- Past floods are what was recorded. The flood outlines come from surveys, aerial photographs and reports; many small floods, and most surface-water floods, were never mapped.
- One town, many streets. Risk is street by street. Check a specific address on GOV.UK’s long-term flood risk service before you buy or rent.
Questions about flooding and hazards in Keswick
Does Keswick flood?
The last flood the Environment Agency recorded inside the town was in October 2021. 12% of homes are at high or medium risk from rivers and the sea on the Environment Agency’s maps, which allow for flood defences. About 8.2% of homes are at high or medium risk from surface water, when heavy rain overwhelms the drains. Keswick grades D− for hazard risk against UK towns.
Which parts of Keswick are at risk of flooding?
From rivers and the sea, the places the Environment Agency warns directly: Keswick Campsite, River Greta at Keswick, Keswick Campsite, Rugby Club and Quinta, River Greta at Keswick, Fitz Park and Riverside Flats areas and Elliot Park at Keswick. Surface water can collect in low spots anywhere in the town. Check a specific address on GOV.UK’s long-term flood risk service.
When did Keswick last flood?
The recorded flood outlines inside the town run from 1977 to 2021 (9 years); the largest was in 2015. Flood warnings have been issued for parts of the town since 2006, most recently on 26 February 2026.
Is Keswick at risk of surface water flooding?
About 5.1% of homes are at high risk and 3.1% at medium risk from surface water, against 12% at high or medium risk from rivers and the sea. Surface water floods come with little warning, and the agencies don’t issue warnings for them.
Is radon a problem in Keswick?
6% of the town’s built-up area is in a radon Affected Area on the BGS/UKHSA atlas. Most homes are below it; a three-month test is the only way to know.
Are there flood warnings in Keswick now?
No flood warning or alert was in force near Keswick at 4 November 2026, 23:16. Live warnings are on GOV.UK’s Check for flooding service and Floodline, 0345 988 1188.
Contains Environment Agency information © Environment Agency and/or database right 2026. Contains British Geological Survey materials © UKRI 2026.
Sources: Environment Agency Risk of Flooding from Rivers and Sea, postcodes in areas at risk (June 2026); Natural Resources Wales Flood Risk Assessment Wales (May 2026); ONS Census 2021 households by postcode · Environment Agency Risk of Flooding from Surface Water (NaFRA2, 2025) and Natural Resources Wales Flood Risk Assessment Wales surface water and small watercourses, read at every address (ONS National Statistics UPRN Lookup, September 2026) and weighted by Census 2021 households by postcode · Environment Agency Recorded Flood Outlines and Natural Resources Wales historic flood map, inside the ONS 2022 built-up-area boundary · Environment Agency Hydrology API (daily maximum river level) and flood-monitoring stage scales · Environment Agency real-time flood-monitoring API · Environment Agency Historic Flood Warnings (January 2006 to June 2026) and flood warning and alert areas · BGS/UKHSA Indicative Atlas of Radon in Great Britain, version 3, by 1 km square · TownRatings grades: our own summary of the data, ranked against UK towns only. All under the Open Government Licence v3.0.
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.