Flood Risk Assessment in Cumbria

Our team at Unda use years of experience to prepare comprehensive flood risk assessments and drainage strategies for commercial and residential sites across Cumbria. A flood risk assessment in Cumbria shows your local planning authority that a development will stay safe from flooding for its whole lifetime, without pushing flood risk onto anyone else.

Cumbria is one of the wettest places in the United Kingdom, drained by three great river systems — the Eden in the north and east, the Derwent in the north and west, and the Kent and Leven in the south — that rise in the high Lakeland fells and reach the sea within a few short, steep miles. We assess every source that matters here, from those rivers and the surface water that overwhelms the towns to the tides on the Solway and Morecambe Bay coasts, then deal directly with the Environment Agency and the relevant Lead Local Flood Authority on your behalf. We guide architects, planning consultants, developers, landowners, home buyers and businesses through to a decision, whether the report is needed for planning, a property purchase, mortgage or insurance, BREEAM, or a surface-water drainage strategy.

If you need a quote or want to talk a site through, contact one of our experienced flood risk consultants on 01293 214444.

Cumbria's rivers rise in some of the steepest, wettest ground in England and reach the sea within hours, so a flood here is decided by what happens upstream and how the rain, the rivers and the tide combine — read them together, or an assessment will not stand up to the Lead Local Flood Authority.

Flood risk assessment in Cumbria at a glance

• One of the wettest counties in England. Open to Atlantic weather and ringed by high fells, Cumbria records some of the heaviest rainfall in the country, with steep, fast-responding rivers that turn a downpour into a flood peak in hours.
• Storm Desmond set the UK rainfall record. In December 2015, 341.4 mm of rain fell at Honister Pass in 24 hours; the Eden, Derwent and Kent flooded together and around 7,465 properties were flooded across the county.
• Two Lead Local Flood Authorities. Since April 2023, Cumberland Council and Westmorland and Furness Council have been the Lead Local Flood Authorities for the county. We work with both.
• Flood Zone 1 is not a free pass. Since the 2025 PPG update, surface water risk can trigger an assessment even on a Flood Zone 1 site.

Check flood risk anywhere in Cumbria

Cumbria is outlined below. Screen any postcode in the county against Environment Agency data for rivers and sea, surface water and the planning flood zones, with a climate outlook to 2125. It is an indicative first pass, not a substitute for a site-specific assessment.

Flood risk in Cumbria: the Eden, the Derwent, the Kent and the coast

River flooding dominates Cumbria. Almost the whole county drains through three river systems that rise in the central fells and fall steeply to the sea: the Eden in the north and east, the Derwent in the north and west, and the Kent and Leven in the south. Add intense rainfall, surface water in the towns and a tidal coast on the Solway and Morecambe Bay, and most sites here face more than one source at once.

Because the catchments are short and steep, rain that falls on the fells reaches the towns below within hours rather than days, which is why Carlisle, Kendal, Cockermouth, Keswick and Appleby have all flooded repeatedly. Understanding which watercourse drives the risk on a given site, and how quickly it responds, is the heart of a credible fluvial flood risk assessment.

• Rivers (fluvial). The Eden and its tributaries the Caldew and Petteril through Carlisle, the Derwent and Cocker at Cockermouth, the Greta at Keswick and the Kent at Kendal flood the valley floors. Land in Flood Zones 2 and 3 along these corridors almost always needs an FRA.
• Surface water (pluvial). Now the most widespread flood risk in England. Intense Lakeland rainfall overwhelms drains in the built-up parts of Carlisle, Kendal and the coastal towns. Since the 2025 PPG update, surface water on the Flood Map for Planning can trigger an assessment even on a Flood Zone 1 site.
• Tidal and coastal. The Solway Firth, the Duddon and Kent estuaries and Morecambe Bay put the west and south coasts — Workington, Maryport, Whitehaven, Barrow, Grange-over-Sands and Ulverston — at risk from high tides and surge, sometimes combining with river flows. See tidal flooding.
• Groundwater and sewers. Permeable valley gravels and limestone can raise water tables that flood low ground and basements without showing on a river map, and the surface-water sewer network backs up in heavy rain — the Lead Local Flood Authority's responsibility. See groundwater flooding and the role the LLFA plays.

Carlisle is the textbook case for why a single map is never enough: three rivers — the Eden, the Caldew and the Petteril — converge in the city, while low-lying neighbourhoods nearby flood from surface water that has nowhere to drain by gravity. A scheme there has to reconcile both. Our notes on the sources of flood risk and on surface water and planning set out how these sources interact.

A history of flooding in Cumbria

These dated events are why authorities here scrutinise development so closely, and why a flood risk assessment in Cumbria has to be evidence-led rather than generic. Each one reshaped local policy and the flood defences a developer now has to design around.

• 1822 and 1968 — the Eden at Carlisle. The River Eden has a long record of flooding Carlisle, with major events in 1822 and again in 1968, when more than 2,500 properties flooded across the area — most of them in the city.
• January 2005 — the Carlisle flood. The Eden, Caldew and Petteril burst together after about nine inches of rain; around 1,800–2,700 properties flooded, three people died and damage ran to roughly £400 million. It triggered the Carlisle flood defences that followed.
• November 2009 — Cockermouth and the Derwent. A then-record 316.4 mm of rain fell at Seathwaite in 24 hours; the Derwent and Cocker overwhelmed Cockermouth, around 1,300 properties flooded and PC Bill Barker lost his life when Northside bridge at Workington collapsed.
• December 2015 — Storm Desmond. 341.4 mm of rain fell at Honister Pass in 24 hours, a UK record. The Eden, Derwent and Kent flooded simultaneously, around 7,465 properties were flooded across Kendal, Carlisle, Appleby, Keswick and Cockermouth, and insured losses were put at roughly £1.3 billion — sediment evidence suggests the worst flooding in more than 500 years.

A pattern runs through all of it: ground that flooded once tends to flood again. A robust assessment treats this recorded history as evidence, not background colour.

Flood defences and schemes protecting Cumbria

Major investment followed 2005, 2009 and 2015, and the schemes change what a development next to them has to prove. A new defence reduces the chance of flooding, but it never removes it, and planning policy still expects the residual risk to be assessed.

• Carlisle Flood Risk Management Scheme. Walls, embankments, storage and pumping along the Eden, Caldew and Petteril, with the first phases completed by 2010 and further work on the Caldew and at Warwick Bridge progressing through 2024–25.
• Kendal and the Kent catchment. A multi-phase Environment Agency scheme is raising protection through Kendal and then Burneside, Staveley and Ings, combining linear defences in the town with upstream storage in the catchment.
• Cockermouth and Keswick. Cockermouth's roughly £4.4 million scheme, completed in 2013, added self-closing barriers and raised defences on the Derwent and Cocker, with later schemes protecting Keswick on the Greta.
• A system under pressure. Steep catchments, record rainfall and climate change mean defences are repeatedly tested, and several were damaged in later high flows — so a defended site is rarely the end of the flood risk story.

The catch for developers is the one we set out in residual flood risk and why a site stays in a flood zone after defences are built: the Flood Map for Planning is drawn as if the defences are not there, so a defended site can still sit in Flood Zone 3. Climate change makes this sharper still, which is why an assessment applies the Environment Agency's allowances over the development's lifetime.

Planning policy and your Lead Local Flood Authority in Cumbria

Two kinds of authority set the rules. The Environment Agency leads on the main rivers — the Eden, Derwent, Kent and the rest — and on the sea. A Lead Local Flood Authority (LLFA) leads on surface water, groundwater and ordinary watercourses, and since April 2023 Cumbria has two of them: Cumberland Council and Westmorland and Furness Council.

Local government reorganisation abolished Cumbria County Council in 2023 and replaced it with two unitary authorities, each its own LLFA: Cumberland Council covers Carlisle, Allerdale and Copeland in the north and west; Westmorland and Furness Council covers Eden, South Lakeland and Barrow in the south. A developer deals with whichever council covers the site, alongside the Environment Agency and the role the LLFA plays as statutory consultee on surface water drainage. Within the Lake District and Yorkshire Dales National Parks the relevant National Park Authority is the planning authority, while the council remains the LLFA. Our overview of who manages flood risk in England explains how the pieces fit together.

Your assessment and drainage strategy must satisfy national policy — the NPPF and its Planning Practice Guidance — and the local framework: each council's Local Flood Risk Management Strategy, its Strategic Flood Risk Assessment and the adopted and emerging Local Plans. Where a higher-risk site is involved, the Sequential and Exception Tests apply, and the right vulnerability classification has to be argued. On drainage, the 2025 national SuDS standards and the four pillars of SuDS shape what each LLFA will accept, with runoff from new development normally restricted towards greenfield rates and attenuated for a climate-adjusted 1-in-100-year storm.

What your flood risk assessment in Cumbria must show

• Risk assessed from every credible source, using the Flood Map for Planning and local data.
• An appropriate location, tested against the Sequential Test where policy requires it.
• Safe for its lifetime, once the climate change allowances are applied.
• No increase in flood risk elsewhere, with attenuation and, where needed, compensatory storage.
• Residual risk managed, with safe access, egress and finished floor levels. Get one of these wrong and the application stalls, as our note on LLFA drainage objections shows.

Development and flood risk assessment in Cumbria

From garden villages around Carlisle to the regeneration of Barrow and conversions in the Lake District, the kind of site you bring forward shapes the assessment you need. The right scope is the difference between a clean approval and a drainage objection that holds an application up for months.

• Urban extensions and garden villages. Large schemes such as St Cuthbert's Garden Village south of Carlisle are multi-phase developments where surface-water drainage and the Eden and Caldew floodplains shape the masterplan.
• Riverside and town-centre regeneration. Regeneration along the Eden, Kent and Derwent through Carlisle, Kendal and Cockermouth frequently sits in Flood Zones 2 and 3, needing finished floor levels, safe access and egress and often compensatory flood storage.
• Coastal and industrial investment. Major investment around Barrow, Workington and the west-coast energy sites brings employment and housing land where tidal risk and extensive impermeable area make the drainage strategy central to the application.
• Rural, tourism and agricultural schemes. Conversions, holiday accommodation and farm diversification across the Lakeland valleys often turn on surface water and ordinary watercourses rather than a main river, and on the right drainage information for planning.

Climate change is not optional here. A Cumbria assessment must apply the Environment Agency's allowances for higher river flows and rainfall over the development's lifetime — generally 100 years for housing — which sets floor levels, freeboard and how much attenuation a drainage scheme needs.

Home buyers and businesses come to us too. A flood risk question can affect a purchase and house prices, and a conveyancing search is not the same thing as a planning-grade assessment. Knowing which you actually need saves time and money, and our guide on whether you can do your own assessment explains where the line falls.

How Unda helps with flood risk assessment in Cumbria

We act as the accurate translation layer between your scheme and the requirements set by the Environment Agency, the relevant Cumbria LLFA and national planning policy. We are experts on the county's flooding, not a generic report mill.

A flood risk assessment in Cumbria from Unda assesses every credible source — the rivers and their tributaries, surface water, groundwater, the tide on the coast, sewers and any ordinary watercourse on the boundary — compares modelled flood levels against your proposed floor levels, sets safe access and egress, and recommends mitigation the regulators will accept. We are a CIWEM Business Partner with chartered members, and a senior consultant signs off every report. Where the council needs it, a surface-water drainage strategy sits alongside the assessment as a separate report so the two cases stay consistent and an objection has nowhere to land.

Flood risk assessments and related reports for every situation in Cumbria

A flood risk assessment, a Sequential or Exception Test and a drainage strategy are three distinct reports. They often travel together in a planning submission, but they answer different questions: is the site safe, should the development be here, and where does the surface water go. We prepare all three, alongside the right form of assessment for buyers, lenders and BREEAM.

Flood risk assessments

• Flood risk assessment for planning. The core report, site-specific and prepared to satisfy the NPPF, the Environment Agency and your Cumbria LPA. Groundwater and, where needed, flood modelling are assessed within it rather than as separate reports.
• Homebuyer and property-purchase survey. For conveyancing, where a search has flagged river, surface-water or coastal risk and you need the actual building assessed, not a broad map.
• Flood risk assessment for insurance. Property-specific evidence for brokers and underwriters where premiums have risen or cover has been restricted — common in towns with a flood history.
• Flood risk assessment for BREEAM. Structured around BREEAM Pol 03, which is credit-driven rather than safety-driven, so a planning FRA alone rarely satisfies it.
• Groundwater flood risk. A defensible design water table for valley-gravel and limestone sites and any basement — assessed as a source within the FRA, or as a standalone hydrogeological assessment on complex sites.

Sequential and Exception Tests

The Sequential and Exception Tests are a separate, locational report about whether a development should be in a higher-risk location at all. The Sequential Test defines an area of search, identifies reasonably available lower-risk sites and justifies the proposed site; the Exception Test is the second gate where development still needs to proceed. A clean site-specific assessment showing the development is not actually within an area at risk can remove the need at application stage — a live policy area, as our note on what the Yatton judgment means for planning explains.

Drainage strategy and SuDS

• Sustainable drainage strategy (SuDS). Surface-water engineering — calculates existing versus proposed runoff and proposes SuDS to hold discharge within the LLFA's standards.
• Preliminary drainage design. The early, outline read that flags infiltration issues before they affect layout and land value.
• Discharge of drainage conditions. The detailed stage to discharge a pre-commencement or pre-occupation drainage condition.
• Flood modelling. 1D and 2D hydraulic modelling — a technique that feeds the assessment, Sequential Test or drainage design where national mapping is not enough, which matters on Cumbria's fast-responding rivers.

Early in a drainage strategy it helps to know whether the ground will take water: our free geology and ground conditions map and BRE 365 infiltration rate calculator give an indicative read before a trial pit, and the drainage calculators help size the scheme. You can screen a postcode on our flood risk map, see the projects we have delivered, and every report is overseen by a chartered flood risk consultant who stays involved past the report to answer objections.

Cumbria flood resources and contacts

The most reliable Cumbria flood information comes from the lead authorities. For an immediate threat to life during a flood, always call 999; for a power cut during flooding, call 105.

• Check for flooding in Cumbria. Environment Agency live warnings, river levels and maps at check-for-flooding.service.gov.uk; sign up for flood warnings or call Floodline on 0345 988 1188.
• Cumberland Council flood risk. Strategy, developer guidance and reporting for the north and west at Cumberland Council.
• Westmorland and Furness flood risk. Flooding, the Strategic Flood Risk Assessment and developer advice for the south at Westmorland and Furness Council.
• The Flood Hub. Practical guidance, scheme updates and community resources for Cumbria at thefloodhub.co.uk/cumbria.
• North West Regional Flood and Coastal Committee. Regional investment and priorities via the North West RFCC.
• Live river levels. Whether the Eden, Derwent or Kent are running high right now via our live river levels map.

For flooding from blocked or burst sewers, contact United Utilities, the water and sewerage company for the county. For broader policy context, our notes on the Environment Agency's planning role and on flood zones 1, 2 and 3 are a good starting point.

Flood risk assessment in Cumbria: frequently asked questions