Flood Risk Assessment in Cumbria

A flood risk assessment in Cumbria now has to begin by naming the right council and the right plan, because Cumbria County Council and its six districts were abolished in April 2023. Cumberland Council covers the north and west and Westmorland and Furness Council the south and east. Inside the Lake District and Yorkshire Dales national parks, the park authority decides the application. The flooding has not changed. Short, steep rivers carry rain from the fells to Carlisle, Keswick, Cockermouth or Kendal within hours, and the coast runs from the Solway Firth to Morecambe Bay.

Our consultants assess flood risk for Cumbrian planning applications, buyers, lenders and insurers, and write the sequential and exception tests and surface water drainage strategies that often go with them. We work on sites in Silloth, Workington, Penrith, Windermere, Barrow-in-Furness and everywhere between.

Storm Desmond put 341.4 mm of rain on Honister Pass in the 24 hours to 6pm on 5 December 2015, a UK record, and about 6,300 households and businesses across Cumbria flooded that month.

Questions about a Cumbrian site can go straight to one of our consultants on 01293 214444 or by email to enquiries@unda.co.uk.

Who decides a planning application in Cumbria since April 2023?

On 1 April 2023 two unitary councils replaced the county council and the districts. Cumberland Council took over the former Allerdale, Carlisle and Copeland areas; Westmorland and Furness Council took over Barrow-in-Furness, Eden and South Lakeland. Each is the planning authority outside the national parks and the lead local flood authority for its whole area, parks included. Neither has adopted a local plan of its own yet, so an application is still judged against the plan of the district it would once have gone to.

Westmorland and Furness published a Level 1 Strategic Flood Risk Assessment in 2026 for its planning area outside both parks. It maps rivers, the sea, surface water, groundwater, sewers, canals and reservoirs as evidence for the council's plan to 2045. In Cumberland the former districts' assessments still stand until the new plan's evidence replaces them. Inside the parks the national park authority decides the application, but drainage on a major scheme is still reviewed by Cumberland or Westmorland and Furness as lead local flood authority.

Screening a Cumbrian postcode before the detailed work

Type a postcode into the map below to see the Environment Agency's flood zones, surface water and reservoir layers at that point, or open our full flood risk map for anywhere in England. It is also the quickest way to see a Cumbria flood map for a single address. The coral line follows the two councils' areas, which together make up the county. A screen like this cannot see a floor level, a culverted beck under a farmyard or the wall that holds back a river, which is why a site-specific assessment still has to follow it.

Flood Zones 2 and 3 describe river and sea flooding only. Surface water, groundwater and reservoir flooding are mapped separately, and our guide to flood zones in England explains how each zone is drawn and what it means for an application.

Rivers that carry rain from the fells to the towns within hours

Most of Cumbria's rivers rise on the Lakeland fells or the Pennine edge and reach a town a few hours after heavy rain. In November 2009 the Seathwaite Farm gauge in Borrowdale caught 316.4 mm in 24 hours, then a UK record. The Centre for Ecology and Hydrology put the Derwent's peak at Camerton at a return period of 500 to more than 2,000 years. Rivers cause most of the county's flooding. The table also shows where surface water (Windermere) and the tide (Whitehaven) add to it.

The River Eden, River Cocker and River Lune have pages of their own, with their gauges and flood histories. For flood monitoring across Cumbria, our live river levels map shows the Environment Agency's gauges on these rivers; the June 2016 flood action plan counted 72 flood warning areas in the county, with more planned.

Cumbria floods since 2005, and what each one changed

Flooding in Cumbria on the largest scale has come in winter, from rivers, after days of rain on saturated fells. Each one changed the defences or the evidence, and each left reports that an assessment for a nearby site should read.

1. January 2005. The Eden, Caldew and Petteril flooded more than 1,800 properties in Carlisle. The Environment Agency's £38 million Carlisle scheme followed and was finished in 2010.
2. 18 to 20 November 2009. Up to 372 mm of rain fell in three days. A government summary counted 2,239 properties affected and 25 bridges closed for more than six weeks, and a police officer died when a road bridge in Workington collapsed.
3. 5 and 6 December 2015. Storm Desmond brought 341.4 mm to Honister Pass in 24 hours and 405 mm to Thirlmere, a 48-hour UK record. About 6,300 households and businesses flooded across the county. By the 2016 flood action plan's count that included about 1,500 homes in Kendal and a similar number in Carlisle, and Keswick's Section 19 report found 515 properties affected there, with defences overtopped or bypassed in nine places.
4. June 2016. The Cumbria Flood Action Plan committed up to £72 million to better protect at least 4,300 homes by 2021, with 48 community flood action groups by then active in the county.
5. May 2024 onwards. Flooding in May 2024 led to Cumberland Council investigations at Great Corby, Cumwhinton and Kates Beck Lane in the Carlisle district, with further reports since for Thursby and, in 2026, Wigton.

Those last reports are Section 19 flood investigations, and both councils publish them: Cumberland lists more than 40 since 2011 and Westmorland and Furness lists 28, from Appleby and Ambleside to Windermere and Pooley Bridge. They name the streets, culverts and becks that flooded, which no flood zone map shows.

What Cumbria's drainage standard asks of new development

Both councils still use the Cumbria Development Design Guide, written by the former county council and last revised in January 2023, as the local standard for sustainable drainage. Its drainage chapter makes greenfield runoff the target for every developed site, and it sets no separate, looser rate for previously developed land.

• Peak rates. For the 1 in 1, 1 in 30 and 1 in 100 year storms, with climate change and urban creep added, runoff from the finished site must not exceed the greenfield peak for the same storm, worked out by the IH124 or FEH methods.
• Volume. Runoff from the 1 in 100 year, six-hour storm must not exceed the greenfield volume, or the extra water must be shown not to raise flood risk on or off the site.
• Where the water goes. Into the ground first, then a watercourse or other surface water body, then a surface water sewer, and a combined sewer only when nothing else is possible.
• Exceedance. Runoff stays inside the drainage system up to a 1 in 30 year storm, no building or vulnerable plant floods in a 1 in 100 year storm with climate change, and anything larger follows routes that keep clear of property.
• Urban creep. Future extensions and paved gardens are allowed for by adding 10% to the impermeable area on schemes of 25 homes a hectare or fewer, falling to 2% at 50 or more, and nothing for flats.

On top of the guide, major schemes are tested against the 2025 national standards for sustainable drainage, which policy F8 of the NPPF now expects all development to follow. In the Lake District, Policy 03 also asks every proposal to show where its surface water will be discharged. Infiltration comes first in the order, so it pays to find out early whether the ground will take water: our ground conditions and soakaway checker gives a first read before any trial pit is dug.

The Solway, the west coast and Morecambe Bay

Cumbria's coast runs from the Solway Firth past Silloth, Maryport, Workington and Whitehaven, then south to Millom on the Duddon estuary, Barrow-in-Furness, Walney Island and the Kent and Leven estuaries in Morecambe Bay. Tidal flooding here often arrives with river or surface water rather than on its own. The county's risk assessment notes that Pow Beck in Whitehaven backs up at high tide, and that rising sea levels will make tide-locked outfalls in Barrow-in-Furness more of a problem for surface water.

• Millom and Haverigg. In January 2026 Cumberland Council announced £40 million from the Environment Agency, with Local Levy and United Utilities contributions, for a flood scheme to protect hundreds of homes and local businesses.
• Walney Island. Westmorland and Furness is running a resilience and adaptation pathways assessment, with a public survey, to help the island plan for its future.
• The whole coast. The former county council led a Cumbria Coastal Strategy to assess coastal flooding and erosion over the long term and the condition of the defences along it.

For coastal sites we prepare flood risk assessments and flood risk due diligence. The long-term policy for each stretch of shore is set in a shoreline management plan (our explainer covers hold the line and managed realignment), and our note on sea level rise sets out the allowances an assessment applies over a building's lifetime.

Building in the Lake District and the Yorkshire Dales

Much of Cumbria lies in one of the two national parks, and both grew on 1 August 2016. The boundary orders added about 70 km² to the Lake District, from Birkbeck Fells to Whinfell and around Sizergh Fell and the Lyth valley, and took the Yorkshire Dales into the Orton Fells, the northern Howgills, Wild Boar Fell, Mallerstang, Firbank Fell and the fells west of the Lune.

Small schemes in the parks, such as a barn conversion, a holiday let, a campsite or an extension in a valley village beside a beck, are still read against flood policy. Policy 03 of the Lake District Local Plan follows national flood policy, backs natural flood management, and asks every proposal to show how its surface water will be discharged. Our guides to barn conversions, holiday lets and farm diversification and campsites and glamping cover what each kind of scheme triggers.

Lake District floods can come from several sources at once. In Keswick in December 2015 the Greta was the main cause, but the Derwent, Derwentwater itself, Cuddy Beck and blocked culverts all added to it, and Westmorland and Furness has published investigations for Ambleside, Grasmere, Windermere and Troutbeck Bridge as well. Upstream storage and natural flood management are now part of the county's response, including on the Kent above Kendal.

The Cumbria Flood Partnership and the schemes still being built

After Storm Desmond the government set up the Cumbria Floods Partnership, which first met in January 2016. Its flood action plan, published that June, had five strands: stronger defences, upstream management, maintenance, resilience and water level management boards. Since reorganisation the work runs through the Cumbria Strategic Flood and Coastal Erosion Risk Management Partnership, on transitional terms while a permanent successor is formed (Westmorland and Furness, December 2024). It is one of five sub-regional partnerships reporting to the North West Regional Flood and Coastal Committee, and its scheme pages sit on The Flood Hub.

• In progress. Carlisle, where new phases are built to Storm Desmond levels with an allowance for climate change; Kendal, with Burneside, Staveley and Ings and storage upstream; and Appleby.
• Proposed. Cockermouth, and the River Caldew through Carlisle.
• Completed. Low Crosby and Rickerby, beside the Eden near Carlisle.
• No drainage boards. There are no internal drainage boards in Cumbria, so land drainage consents go to the councils or, on a main river, the Environment Agency.

A defence lowers the chance of flooding but does not move land out of the flood zone, because flood zones are drawn as if the defences were not there. Our pages on residual flood risk and on why a site stays in a flood zone after new defences explain what an assessment behind a Cumbrian wall or embankment still has to show.

Is a flood risk assessment in Cumbria needed for your proposal?

Policy F4 in chapter 18 of the NPPF sets the national triggers: any site in Flood Zone 2 or 3, a Flood Zone 1 site of one hectare or more, and land that the Environment Agency's maps or the council's evidence show at risk from surface water or another source. On drainage, the county guide described above then applies on top.

A site at risk only from surface water can sometimes do without the sequential test: under policy F5 the test is not needed where the assessment shows the development will be safe, and our note on the surface water exemption sets out the conditions. Our NPPF flood risk guidance explains how chapter 18 works above the eight Cumbrian plans.

Reports for Cumbrian sites, from fell farms to the coastal works

The three main reports answer different questions. A flood risk assessment asks whether a development and the people in it will be safe; the sequential and exception tests ask whether it should be built there at all; a drainage strategy shows where the rain that lands on it will go. The consultants who write them are chartered, a senior consultant signs each one off, and Unda is a CIWEM Business Partner. Any of these can be prepared for a site anywhere in Cumbria:

• Several sources at once. A beck, a lake, the tide and a blocked culvert can all reach the same Cumbrian plot. A flood risk assessment weighs every one of them.
• Planning applications. Whether the case officer works for Cumberland, Westmorland and Furness or a national park authority, a flood risk assessment for planning answers the plan's flood policy and chapter 18 of the NPPF.
• Buying a home. Streets in Carlisle, Keswick, Appleby and Kendal that flooded in 2015 can be flagged by a search or a lender, and a flood risk survey for property purchase sets out what the flag means for that house before you exchange.
• Homes in a flood zone. Where housing is proposed in Flood Zone 2 or 3, a sequential and exception test looks for reasonably available sites at lower risk and, where the exception test applies, shows the scheme is safe and brings wider benefits.
• Major schemes. On ten homes or more, Cumberland or Westmorland and Furness reviews the drainage strategy against the county's own standard and the national one.
• Greenfield rates. A surface water drainage strategy works out the greenfield peaks and volume the Cumbrian standard asks for and sizes the storage that holds runoff to them.
• Pre-commencement conditions. Many Cumbrian permissions come with a condition reserving the drainage details, and discharge of drainage conditions supplies the calculations, layout and maintenance plan the council asks for before work starts.
• Premiums after 2015. Owners in towns that flooded in Storm Desmond can use a flood risk assessment for insurance to show an insurer the risk to the building as it stands now, with the newer defences taken into account.
• Coastal and industrial land. On the west coast and around Barrow-in-Furness, where outfalls can be tide-locked, flood risk due diligence tests a site before it is bought or refinanced.
• Shops, hotels and campsites. Keswick's investigation named supermarkets, a museum, hotels and campsites among the properties hit in 2015, and a business continuity flood risk assessment plans how a business keeps trading when the water rises.
• Beyond the sewer network. Farms, holiday lets and valley houses away from the public sewer need a foul drainage strategy, and South Lakeland's policy DM6 expects a sewer connection wherever one is available.
• Rising groundwater. The county strategy records groundwater affecting up to 12 properties a year on Aynam Road in Kendal and regularly flooding Kennedy Street in Ulverston; a groundwater flood risk assessment tests basements and soakaways against it.
• Fast rivers without site levels. Where the Environment Agency's data gives no flood level for a site on the Eden, the Derwent or the Kent, flood modelling provides one.
• Behind the defences. Homes and holiday lets that rely on the Carlisle, Keswick or Kendal defences, or sit in one of the county's flood warning areas, may need a flood warning and evacuation plan saying when and how people leave.
• Land for the new plans. With new local plans due from Cumberland in 2028 and Westmorland and Furness in 2029, and the Lake District's review in 2028, a flood risk feasibility study tests land before it is promoted.

Town pages inside Cumbria, and the counties next door

For a site in one of these towns, its own page goes further into the streets, the defences and the policies that apply:

• Carlisle. Where the Eden, Caldew and Petteril meet, with the 2005 and 2015 floods and the city's scheme phases.
• Cockermouth. At the confluence of the Derwent and the Cocker, flooded in 2009 and again in 2015, with a scheme still at the proposal stage.
• Kendal. On the Kent, where the 2016 flood action plan counted about 1,500 homes flooded in Storm Desmond, and where the flood scheme is being built in phases.

Over the county boundary, our pages for Lancashire, Northumberland, County Durham and Yorkshire cover the neighbouring authorities, and every county and town we cover is listed under areas.

Reporting flooding in Cumbria, and who deals with what

If floodwater puts anyone in danger, ring 999; ring 105 for a power cut. Otherwise, the body to contact depends on where the water is coming from.

The county's Local Flood Risk Management Strategy, adopted on 10 November 2022 just before reorganisation, is still the strategy both councils work to. Its action plan and the risk assessment that ranks Cumbria's communities are published as annexes alongside it.

Questions about flood risk assessments in Cumbria

Whether the site is a farmyard above Ullswater or a plot on the Barrow waterfront, our consultants can tell you what it needs. Call 01293 214444 or email enquiries@unda.co.uk.