Flood Risk Assessment in Preston

A flood risk assessment in Preston, Lancashire, begins with the River Ribble, which is tidal by the time it reaches the city. The Environment Agency names its Broadgate and Riversway warning areas after the Ribble estuary rather than the river, and its Penwortham gauge, on the bank opposite Broadgate, rises and falls with the tide. Savick Brook, a second main river, crosses Fulwood, Cadley and the Larches before reaching the estuary by the docks. We write flood risk assessments in Preston for planning submissions, for buyers before exchange and for lenders and insurers, alongside sequential and exception tests and surface water drainage strategies.

Here Preston means the city's continuous built-up area, which the Office for National Statistics maps in two parts, Preston and Fulwood. That takes in the city centre, Avenham, Frenchwood, Fishwick, Deepdale, Plungington, Ribbleton, Brookfield and Grange; Ashton-on-Ribble, Broadgate, Riversway and the docks, the Larches and Lea to the west; and Fulwood, Sharoe Green, Cadley, Ingol and Tanterton to the north, across most of the PR1 and PR2 postcode districts. Penwortham and Walton-le-Dale, over the river in South Ribble, and Cottam, Broughton and Grimsargh on the northern fringe are mapped as separate places.

Preston's Core Strategy names southwest Preston, alongside Croston, Penwortham and Walton-le-Dale, as an area where inappropriate development in flood risk areas is to be avoided. Broadgate, Ashton's riverside and the Riversway docklands all sit within that description, new walls or not.

To discuss an address in Preston, call 01293 214444 or email enquiries@unda.co.uk. Before we quote, we check the site against the estuary and Savick Brook warning areas and the Central Lancashire flood studies.

Is Preston in a flood zone? The tidal Ribble and Savick Brook warning areas

Parts of it are. The Flood Map for Planning shows Flood Zone 3 along the Ribble as it passes the city, and the 2025 Level 1 SFRA records a wider spread of Flood Zone 2 around Preston Dock on the west side. Large parts of the northern and eastern suburbs, Fulwood and Ribbleton among them, are in Flood Zone 1. Seven Environment Agency warning areas cover streets inside the outline:

Two different triggers sit behind these. The Broadgate and Riversway areas respond to high tides and surges in the estuary, which is why the Penwortham record was set in April 2024 rather than during a winter flood. The Avenham and Fishwick areas respond to river flow: upstream at Samlesbury the Ribble reached 6.56 m on 26 December 2015, 1.5 m above the level at which property flooding becomes possible there. Our live river levels map shows the Ribble, Darwen and Lostock gauges as they report.

Search a PR1 or PR2 postcode on the map

Enter a postcode below to see the planning flood zones, surface water extents and any warnings in force, or use our flood risk map for an address anywhere in England. The coral line traces the built-up area of Preston and Fulwood from the Office for National Statistics.

Savick Brook through Fulwood, Cadley and the Larches

Savick Brook is shown as main river on the Environment Agency's statutory map where it runs through Fulwood and Cadley, so the Agency rather than the county council regulates works on its banks there. The SFRA lists it among the Central Lancashire watercourses with tidal reaches, and its lowest section now carries a navigation: the Millennium Ribble Link, which opened in July 2002 and joins the Lancaster Canal to the Ribble through nine locks, one of them a sea lock.

• Fulwood Bridge and Talbot Street. The upstream warning area runs from Sharoe Green Lane to the railway line and names the terraces around Talbot Street and Black Bull Lane.
• Cadley and Mill Lane. Downstream, between Woodplumpton Road and Black Bull Lane, the warning lists Drakes Close, Seymour Road, Mill Lane and Mill Gate.
• Fulwood Barracks. The 2025 Level 2 SFRA assessed the 16.9 hectare barracks site on Watling Street Road for housing. It drains to an unnamed tributary of Savick Brook, only about 1% of it is at surface water risk, and the residual risk comes from culverts to the north that could block (Level 2 SFRA, Preston sites).
• The Lancaster Canal. The Canal & River Trust's records in the SFRA show five overtopping incidents on the canal at Cottam between 2010 and 2014, just west of Ingol and Tanterton.

Because the brook's lower reach is tide-influenced, a high tide in the estuary can hold water back up the channel while rain is still falling on Fulwood. A site near the brook is assessed for both, and for what happens if a culvert under one of the estates is blocked.

Floods recorded in Preston since 2015

Recorded property flooding in the city since 2015 has mostly come a few buildings at a time, from heavy rain, blocked gullies and overloaded drains. The county council's flood reports and the 2025 SFRA list these events:

1. 26 December 2015. The Pavilion in Avenham Park and a property in the Cadley area flooded internally, according to the county council's district flood report for Preston (Lancashire County Council, 2017).
2. June and August 2016. Heavy rain flooded the outside of one property in the city in June and two in August.
3. November 2017. Intense rain caused surface water flooding to three properties in the city.
4. June 2018. A blocked gully flooded the outside of a property in Fulwood; Sharoe Green Lane is on the county council's list of affected streets.
5. 9 February 2020. The Ribble set its highest reading at the Walton-le-Dale gauge, 5.45 m, more than a metre above the level at which property flooding becomes possible.
6. June 2020. Surface water and combined sewer flooding in Preston, Broughton and Woodplumpton, recorded in the North West flood risk management plan.
7. 12 July 2021. A band of intense rain put Lower Bank Road and Watling Street Road in Fulwood, and Fylde Road and Patten Street near the university, on the county council's list of affected streets.
8. 9 April 2024. The tidal Ribble reached 6.06 m at Penwortham, the highest level on record there.

Apart from the pavilion on the Avenham riverside, these sources list no buildings in the city flooded by the Ribble in that period. The question a site-specific assessment in Preston has to answer is what happens behind the defences if they overtop, breach or are left open.

The new Broadgate walls and floodgates: what they change for a site

Phase 1 of the Environment Agency's Preston and South Ribble scheme is complete. In Broadgate and Riverside the old defences gave way to precast concrete wall panels, with glass panels on top between the Gas Pipe Bridge and the Miller Garden apartments, and the floodwall now continues to the Miller Park entrance beside the West Coast Main Line, reopened on 17 June 2026 (The Flood Hub).

• Four floodgates. Two at the Miller Park entrance, one near Ribble Cottage and one at Miller Garden Apartments. They stand open and are closed by the Environment Agency only when a flood warning is issued.
• Who it protects. The scheme as a whole is designed to better protect around 5,000 homes and businesses on the Ribble and the Darwen (scheme overview).
• What is still under way. Phase 2, raising defences in Walton-le-Dale on the South Ribble side, is under construction. Maintenance on the existing Frenchwood defences has been completed.
• What the defences were built to. The SFRA lists ten walls and twenty embankments on the Ribble through the city. Where the design standard is recorded, most are 1 in 100 year defences.

None of this moves a site out of Flood Zone 3 on the planning map, which shows land as if the defences were absent, so the sequential test still applies to a new home in Broadgate. What changes is the evidence: an assessment for a site behind the walls draws on the defended model, the residual risk from a breach or an open gate, and the access route along the river. Our guide to flood defences and residual risk explains the difference.

Riversway, Strand Road and Wallend Road: docklands land in the 2025 SFRA

The west of the city, from the docks to Ashton-on-Ribble, holds the larger brownfield and employment sites. The Level 2 SFRA tested three of them against the estuary and river models, with climate change added:

Employment is a less vulnerable use, so none of these needs the exception test, although unallocated land still faces the sequential test. Each needs an assessment that deals with the breach case and with depths that rise as the estuary does. Homes or a hotel on the same land would be more vulnerable, and in Flood Zone 3a would need the exception test too.

Policy 29 and draft Policy EN10: what a flood risk assessment in Preston must show

Preston City Council decides applications under the Central Lancashire Core Strategy of July 2012 and its own Local Plan 2012 to 2026, with the National Planning Policy Framework. The replacement Central Lancashire Local Plan was submitted in June 2025 and is still at examination:

The SFRA adds that the national surface water map can pick out land in Flood Zone 1 with drainage problems, and that this evidence should inform the sequential test. So a Preston site outside the river zones can still be asked to show it is the better choice when a surface water flow path crosses it.

Combined sewers, groundwater and the reservoir map in Preston

Away from the river, the problem lies in the drainage under the older city. The SFRA, drawing on the county's flood strategy, notes that much of Preston's system is made up of combined sewers, which carry foul and surface water in the same pipe and can surcharge in a storm. Its surface water mapping marks the city among the high-risk areas of Central Lancashire.

• United Utilities programme. The company has allocated £25 million to a Preston climate resilience programme for delivery by 2030, looking at natural flood management, SuDS, sewer separation and rainwater harvesting (Preston City Council).
• Sewer capacity. Core Strategy clause 29(f) asks for development to be timed so it does not exceed sewer capacity, so a connection to a combined sewer needs the receiving network addressed early.
• Groundwater. JBA's groundwater map in the SFRA picks out parts of the city, and the SFRA asks for groundwater to be checked site by site, particularly where infiltration is proposed.
• Reservoirs. The SFRA notes that the main reservoir risk in Preston, on the Environment Agency's reservoir flood map, falls on the city centre. An assessment records it as a residual risk alongside the river and the tide.

For a brownfield site off Fylde Road or in Plungington, that usually means a drainage strategy that separates surface water from the existing combined connection and slows it before it leaves the site. Our note on foul, surface water and combined sewers sets out how to tell them apart on the records.

Reports for Preston sites, from a Fulwood terrace to the docks

Each report is written for the address: which side of the defences it sits on, whether the tide or Savick Brook reaches it, where its water goes and what the council, a lender or an insurer has asked for.

• Applying to Preston City Council. A scheme in Flood Zone 2 or 3, or on a hectare or more anywhere, needs a flood risk assessment for planning that answers Policy 29 and the Central Lancashire SFRA.
• Every source at one address. A flood risk assessment weighs the tidal Ribble, Savick Brook, surface water, the combined sewers, groundwater and the reservoir map for the site in question.
• Buying in Broadgate or Fulwood. Before exchange on a house by the river or near Savick Brook, a flood risk survey for property purchase checks the building against its warning area and the defences in front of it.
• New homes on unallocated land. Behind the Broadgate walls the planning map still shows Flood Zone 3, so new dwellings there need a sequential and exception test report.
• Foul and surface water together. A drainage strategy shows where both go and what United Utilities will accept, which matters where the street sewer is combined.
• Ten homes or more. Major schemes go to the county council for comment, so a surface water drainage strategy sets the discharge rate and the SuDS features against the 2025 national standards.
• After permission. We prepare the calculations, layout evidence and maintenance plan needed for the discharge of drainage conditions on a Preston consent.
• Breach and tide. On the docklands and Strand Road land the SFRA asks for a breach of the Ribble embankment to be modelled at application stage, and flood modelling is how that breach is tested.
• Premises at Riversway. Businesses at Riversway, on Strand Road or by Wallend Road can use a business continuity flood risk assessment to plan around the estuary warnings.
• When the gates close. Flats and workplaces behind the Miller Park and Ribble Cottage floodgates often need a flood warning and evacuation plan tied to the Broadgate warnings.

Penwortham, Walton-le-Dale and the edges of the city

Penwortham, Lower Penwortham, Walton-le-Dale and Bamber Bridge sit across the Ribble in South Ribble, which is a separate planning authority working from the same Central Lancashire SFRA and the same county drainage rules; the Fishwick and Frenchwood defences face them across the river. To the north and west, Cottam, Broughton and the North West Preston growth area under Local Plan Policy MD2 are inside Preston's council area but outside the outline, and the Level 2 SFRA places land there in the Savick Brook and Woodplumpton Brook catchments.

The River Darwen, which our Blackburn page follows through that town, joins the Ribble at Walton-le-Dale just upstream of the city. Blackpool has its own unitary council and flood authority, covered on our Blackpool page, and the wider county is on our Lancashire page and in our areas we cover. Looking for Preston Park in Brighton or East Preston near Worthing? Those are on our Brighton and Hove and West Sussex pages.

Who handles which flood in Preston

Responsibility in the city is split by the source of the water:

Work in or beside an ordinary watercourse needs the county council's ordinary watercourse consent; work on the Ribble or the main river length of Savick Brook needs the Environment Agency's permission instead.

Questions people ask about Preston sites

For a house on Riverside, a yard near Strand Road or a plot off Watling Street Road, call 01293 214444 or email enquiries@unda.co.uk. Unda Consulting Limited is a CIWEM Business Partner, and a senior consultant signs off every report our chartered consultants prepare.