Flood Risk Assessment in Blackpool

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

Blackpool sits on the open Fylde coast, where the live issues are rarely a river. The seafront is held by hard sea defences, the streets behind them flood from surface water when the drains and combined sewers fill, and the water table rides high in the blown sand and peat the town is built on. We read those sources together — the defended tidal coast, the surface water that overwhelms the urban drainage, and the groundwater rising from below — then deal directly with the Environment Agency and Blackpool Council’s flood team 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.

Most of Blackpool screens as Flood Zone 1 only because the coast is defended — so the real test of a development here is surface water, drainage and the residual risk behind the sea wall, the things a generic desktop report misses and the council looks for first.

Flood risk assessment in Blackpool at a glance

• Surface water is the day-to-day risk. Flow routes follow the roads through the built-up town, and in heavy rain the combined and surface-water sewers reach capacity — the mechanism behind Blackpool’s worst recent flooding.
• The coast is defended, not risk-free. The entire Blackpool frontage is protected by hard sea defences, but a defended site still carries residual tidal risk and usually still needs that risk assessed.
• Blackpool is its own Lead Local Flood Authority. Blackpool Council — not Lancashire County Council — leads on surface water, groundwater and ordinary watercourses within the borough.
• Flood Zone 1 is not a free pass. Since the 2025 PPG update, surface water risk and critical drainage can trigger an assessment even on a Flood Zone 1 site.

Check flood risk anywhere in Blackpool

Blackpool is outlined below. Screen any postcode in the borough 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 Blackpool: the defended coast, surface water and groundwater

Blackpool’s flood risk does not come from a major river. It comes from three sources working together: the Irish Sea held back by the seafront defences, the surface water that overwhelms the town’s drains in heavy rain, and a high, tidally influenced water table in the sand and peat beneath the streets. Most sites here face more than one of these at once, which is why a single national map is never enough.

As the town grew, its small watercourses were largely culverted and connected to the combined sewer network, so on the surface Blackpool reads as a dense urban grid rather than a river catchment. That is exactly why surface water dominates: when intense rain falls on hard ground and the sewers reach capacity, the water has nowhere to go. Reading that picture correctly is the heart of a credible surface water flood risk assessment.

• Surface water (pluvial). Now the most widespread flood risk in England and the dominant one in Blackpool. The Environment Agency’s surface water mapping shows flow routes following roads through the main urban area, with isolated ponding affecting properties across the town. 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 Irish Sea is the high-consequence source. The whole frontage is defended, but the Flood Map for Planning is drawn as if those defences are not there, so land behind the sea wall can still sit in Flood Zone 2 or 3 and carries residual flood risk from overtopping or breach.
• Groundwater. Blackpool is built on blown sand, peat and tidal deposits over glacial till, with a tidally influenced water table and deeper pressurised aquifers. A high water table floods low-lying ground and basements without ever showing on a river map, and it is critical for any soakaway. See groundwater flooding.
• Sewers and ordinary watercourses. The surface-water and combined sewer network backs up in heavy rain, and the remaining open ditches behind the resort can surcharge. This is Blackpool Council’s responsibility as Lead Local Flood Authority rather than the Environment Agency’s — see the role the LLFA plays.

Because the ground is sand and peat with a high water table, infiltration is rarely the easy answer it looks like on paper, and assuming a soakaway will work is a common way to draw an objection. Our notes on the sources of flood risk and on whether flood maps are accurate set out how these sources interact on a real site.

A history of flooding in Blackpool

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

• 22 November 2017 — the surface-water flood. Blackpool Council’s Section 19 investigation recorded a storm it described as a once-in-64-year event. Ground and sewers were already saturated by earlier rainfall, the flat watercourses could not drain, and residents were forced from their homes. The failure of one of the five pumps at Anchorsholme pumping station made the flooding worse than it would otherwise have been.
• A pattern of coastal pressure. Long-term erosion and beach lowering on the open Fylde coast have driven repeated rounds of sea-defence investment, with the underlying clay at Anchorsholme exposed at times as the beach is lost.
• The lesson for assessments. Blackpool’s flooding turns on saturated ground, sewers at capacity and the performance of pumps and defences — not a river bursting its banks. An assessment that only reads the river-and-sea map misses what actually floods the town.

A pattern runs through all of it: ground that flooded once tends to flood again, and the failure of a single pump or defence is enough to do it. A robust assessment treats this recorded history as evidence, not background colour.

Sea defences and drainage schemes protecting Blackpool

Major investment protects Blackpool from the Irish Sea and from surface water, and those 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.

• The Anchorsholme Coast Protection Scheme. An Environment Agency-funded scheme in the north of the town, designed to protect around 5,000 homes from flooding and coastal erosion using rock groynes to raise beach levels and a rock revetment to absorb wave energy, with construction running from 2026. It sits alongside the Anchorsholme Park underground storage and long sea outfall built by United Utilities.
• The Blackpool South Surface Water Strategy. A roughly £30 million United Utilities scheme that separated surface water from the combined sewers across about 700 hectares of south Blackpool — new surface-water sewers, a 4,000 m³ detention tank at Fishers Field and 13,000 m³ of attenuation basins, discharging to sea via the Harrowside culvert — to cut spills and reduce surface-water flooding.
• A defended town, not a risk-free one. Defences from the recently rebuilt central seafront to older walls in the north have a finite life and a design standard, so climate change and continued development keep the system under pressure.

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 sea defences are not there, so a defended seafront site can still sit in Flood Zone 3. Our note on the difference between the long-term flood risk map and the Flood Map for Planning explains why the public risk map and the planning map disagree on the same defended site.

Planning policy and your Lead Local Flood Authority in Blackpool

Two kinds of authority set the rules. The Environment Agency leads on the sea and any main river. A Lead Local Flood Authority (LLFA) leads on surface water, groundwater and ordinary watercourses — and because Blackpool is a unitary authority, the LLFA is Blackpool Council itself, separate from Lancashire County Council next door.

Blackpool Council is the Lead Local Flood Authority for the borough under the Flood and Water Management Act 2010, working with Lancashire County Council and Blackburn with Darwen on the joint Lancashire and Blackpool flood risk management strategy. A developer here deals with Blackpool’s flood team, alongside the Environment Agency and the role the LLFA plays as statutory consultee on surface water drainage. 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: the Lancashire and Blackpool flood risk management strategy, the Strategic Flood Risk Assessment for the Fylde coast and Blackpool’s adopted Local Plan flood policies. The Environment Agency is a statutory consultee on sites in Flood Zones 2 and 3 and on Flood Zone 1 sites within an area it has defined as having critical drainage problems, which makes a critical drainage area check essential before the layout is fixed. 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 the council will accept.

What your flood risk assessment in Blackpool must show

• Risk assessed from every credible source — tidal, surface water, groundwater and sewers — 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 Environment Agency’s 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, housing and flood risk assessment in Blackpool

Blackpool is one of the most intensively regenerated towns in the North West, and the kind of site you bring forward shapes the assessment you need. Much of the work here is dense brownfield infill and change of use rather than greenfield release, which puts surface water and drainage at the centre of almost every application.

The town’s housing stock is unusual: street after street of Victorian and Edwardian terraces and former boarding and guest houses, many converted into flats and houses in multiple occupation, concentrated in the central and southern resort wards. Conversions, de-conversions back to family homes and holiday-apartment schemes all change the drainage and the occupancy of a building, and a change of use can bring flood risk and drainage into a planning application that an owner did not expect.

• Resort-core regeneration. Schemes such as the Blackpool Central leisure quarter at the foot of the Tower and the Talbot Gateway around the tram and rail interchange are large, high-density brownfield projects where surface-water drainage and residual tidal risk shape the design from the start.
• Housing renewal. The Central Drive and central housing regeneration programmes are clearing poor-quality converted stock and building new energy-efficient homes, where each plot’s drainage and runoff must be re-thought on constrained urban ground.
• Guest-house and HMO conversion. Converting, sub-dividing or de-converting the resort’s boarding houses changes occupancy and drainage, and many of these properties sit in areas covered by an Article 4 direction, so the planning route is rarely automatic.
• Marton Moss and the Airport Enterprise Zone. Employment and data-centre proposals on the low, flat, peaty ground at Marton Moss and the Blackpool Airport Enterprise Zone are drainage-critical: high groundwater and extensive impermeable area make the surface-water strategy the heart of the application.

Climate change is not optional here. A Blackpool assessment must apply the Environment Agency’s allowances for higher sea levels 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 doing your own assessment explains where the line falls.

How Unda helps with flood risk assessment in Blackpool

We act as the accurate translation layer between your scheme and the requirements set by the Environment Agency, Blackpool Council as Lead Local Flood Authority and national planning policy. We are experts on Blackpool’s flooding, not a generic report mill.

A flood risk assessment in Blackpool from Unda assesses every credible source — the defended tidal coast, surface water, the high water table and the combined sewers — 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 Blackpool

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 Blackpool Council. 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 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.
• 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 Blackpool’s sand, peat and tidal deposits 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 council’s required rate, working with Blackpool’s sandy, high-water-table ground.
• 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.

Because Blackpool’s ground is sand and peat with a high water table, infiltration often fails, so testing the ground early matters. Our free geology and ground conditions map and BRE 365 infiltration rate calculator give an indicative read before a trial pit, our note on whether you need infiltration testing and on permeable paving explain what the council expects, and the drainage calculators help size the scheme. You can screen a postcode on our flood risk map, and every report is overseen by a chartered flood risk consultant who stays involved past the report to answer objections.

Blackpool flood resources and contacts

The most reliable Blackpool 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 Blackpool. Environment Agency live warnings, river and sea levels and maps at check-for-flooding.service.gov.uk; sign up for flood warnings or call Floodline on 0345 988 1188.
• Blackpool Council flood risk. The Lead Local Flood Authority’s strategy, investigations and how to report flooding at Blackpool Council.
• Lancashire and Blackpool flood strategy. The joint Local Flood Risk Management Strategy 2021–2027 via Lancashire County Council.
• Fylde Coast Strategic Flood Risk Assessment. The 2024 Level 1 SFRA evidence base covering Blackpool, Fylde and Wyre via the Fylde Coast authorities.
• Sewer and water supply flooding. United Utilities is the water and sewerage company for Blackpool and the North West.
• Live river levels. Check whether nearby gauges are running high right now via our live river levels map.

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, and our hub of flood risk assessment services sets out the full picture. Blackpool sits within historic Lancashire, so our flood risk assessment in Lancashire page covers the wider county.

Flood risk assessment in Blackpool: frequently asked questions