Flood Risk Assessment in Deptford

A flood risk assessment in Deptford usually starts at Deptford Creek, the tidal last kilometre of the River Ravensbourne before it meets the Thames. Walls along the Creek and the Thames frontage keep the tide out of north Deptford. Even so, Lewisham's own site evidence places the riverside and Creekside land in Flood Zone 3. Our consultants prepare flood risk assessments in Deptford for planning, for buyers and their lenders, and for insurance, as well as sequential and exception tests and surface water drainage strategies.

On this page Deptford means two Lewisham wards. Evelyn runs from Convoys Wharf and the Pepys Estate along the river to Deptford Park and Evelyn Street. The Deptford ward takes in Deptford High Street, Deptford Creekside and the streets down to Deptford Broadway, close to Deptford Bridge, where the river turns tidal. Together they cover most of the SE8 postcode district and a corner of SE14. One boundary is easy to miss: a pocket west of the Creek, around St Nicholas's church and Deptford Green, belongs to the Royal Borough of Greenwich, so planning applications there go to Greenwich rather than Lewisham.

Lewisham's flood study models breaches in the Thames and Creek walls. By 2100 the water it shows covers much of the borough's northern tip, and across large parts of it the hazard is rated a danger to everyone.

To talk through a Deptford site with one of our flood risk consultants, call 01293 214444 or email enquiries@unda.co.uk.

Tide in the Creek, rain on the streets: what floods Deptford

Four sources shape most Deptford sites. The tide presses against the Thames and Creek walls, heavy rain falls on a densely built district drained by combined sewers, groundwater sits in the gravels and chalk under the north of the borough, and the Ravensbourne brings water down from south London. On a Creekside plot all four apply at once.

Because the Creek and the Ravensbourne are main rivers, the Environment Agency advises on schemes beside them, while Lewisham Council handles surface water and groundwater. Our explainers on tidal flooding and surface water flooding set out how each behaves.

Check a Deptford postcode, from Convoys Wharf to Creekside

Type a Deptford postcode below to screen it against Environment Agency data for rivers and the sea, surface water and reservoirs, or open our full flood risk map for anywhere in England. The coral outline follows the Evelyn and Deptford wards. Rotherhithe lies past its north-western corner, the Royal Borough of Greenwich across the Creek, and the Greenwich pocket by St Nicholas's church sits just outside it at the Creek mouth. The flood zone on the map ignores the walls, which is why a defended street can still be Flood Zone 3.

Wharf walls and the breach case along Deptford Creek

The Thames and Creek defences hold back almost every tide. What a Deptford assessment has to answer is the rest: water coming over or through a wall in an extreme event, and who is responsible for keeping each wall standing.

• Not every wall was built as a defence. The SFRA's list of informal defences in Lewisham includes the wharves along Deptford Creek, an embankment at the Deptford Environmental Centre and the walls of several buildings beside the Creek. They keep the tide out only because they are there, and since they were built for other purposes, a survey of their condition belongs in the evidence for any site that relies on them.
• Breaches tested from the Thames to the Creek. The Environment Agency's breach model, used in the SFRA, tests 20 m breaches in hard defences and 50 m in soft ones. At present-day levels the flooding inside Lewisham stays beside the Creek and between the river and the A200 Evelyn Street, with the worst hazard next to the walls. For 2100 it covers much of the northern tip of the borough. Our guide to residual flood risk explains how a site uses those results.
• Owners keep the walls. Policy SD7 asks applicants, where appropriate, to survey the defences and watercourse structures on their land and repair them, and riverside owners to raise the Thames walls in line with Thames Estuary 2100. The plan also asks for an undeveloped strip beside the walls: 16 m by tidal rivers and 8 m by fluvial ones, unless the council and the Environment Agency agree another distance. Walls that protect on paper but not in practice are the reason that survey matters.
• Two Thames Estuary 2100 units meet here. The Wandsworth to Deptford policy unit includes parts of Deptford, and the Greenwich policy unit starts between Deptford and Greenwich. Both carry policy P5. That means further action to reduce flood risk, with owners expected to adapt and raise their defences by 2050. The barrier is expected to last until about 2070. Our article on the Thames Barrier looks at what may follow it.
• The tide gauge downstream. At the Environment Agency's Charlton gauge, the statutory defence level is 5.18 m and the highest level on record is 4.74 m. Flooding of low-lying land becomes possible above 4.40 m, when alerts may be issued.

Deptford's flood record, from 1928 to the Tideway shaft

The record is thin. Most of the dates below come from the borough's own flood study, and few of them concern Deptford itself rather than the catchment upstream or London as a whole. So an assessment here leans on the Environment Agency's models more than on the local record.

1. 7 January 1928. The Thames flood that killed 14 people across London reached only the northern tip of what is now Lewisham, according to the Environment Agency's historic flood maps as summarised in the SFRA. The opposite bank was hit harder.
2. September 1968. Heavy rain sent the Ravensbourne, the Pool and the Quaggy over their banks upstream, worst around Lewisham shopping centre, Ladywell Fields and Lewisham Hospital. Deptford Creek carries that same catchment to the Thames; our article on the Great Flood of 1968 tells the wider story.
3. 2006 to 2011. Bursts of heavy rain in June and July 2006 brought flooding reports from across the borough, blamed mostly on blocked or undersized gullies. Lewisham's 2011 preliminary flood risk assessment then named the area of Deptford south of the A2 among places with repeated surface water flooding of property.
4. 2025. Tideway linked the Deptford Storm Relief sewer overflow to the super sewer through a 48 m shaft at Deptford Church Street. The overflow used to send nearly 1.5 million tonnes of storm sewage to the Thames in a typical year, a figure Tideway expects to fall by about 90%. Our article on London's super sewer explains what it intercepts; a new connection still needs Thames Water's agreement.

Three Environment Agency warning areas cover the outline. Each shows whether a warning is in force in Deptford today. Tidal Thames from Deptford Creek to Rotherhithe Station names east Deptford and Convoys Wharf, Tidal Thames at Deptford and Southwark Park covers west Deptford, and Ravensbourne at Deptford watches the river itself. The Charlton and Tower Pier tidal gauges, and the Ravensbourne stations upstream at Catford, appear on our live river levels map.

Convoys Wharf, Deptford Landings and the Creekside sites

Most new homes in Deptford will come from a few allocated sites, and the council's 2023 sequential and exception test paper puts nearly all of them in Flood Zone 3 behind the defences. Allocated land has one advantage. A site that passed the sequential test when it was allocated does not need to repeat it, the Local Plan says, unless the proposed use differs from the allocation.

Convoys Wharf already has planning permission, granted in March 2015 after the Mayor of London determined the application. Floor levels, basements and drainage are still settled plot by plot as the scheme comes forward, so the flood questions return at each stage. Lower Creekside's place in a groundwater protection zone also limits infiltration there: policy SD8 rules out any SuDS that would harm groundwater, and our note on source protection zones explains the restriction.

What Lewisham's Local Plan asks of a flood risk assessment in Deptford

Lewisham Council is both the planning authority and the Lead Local Flood Authority for Deptford: it decides the application and comments on the drainage, while the Environment Agency advises on the Thames, the Creek and the Ravensbourne. The Lewisham Local Plan 2020 to 2040, adopted by Full Council on 16 July 2025, replaced the 2011 Core Strategy and the 2014 development management policies. Two of its policies contain the flood tests.

• When SD7 requires an assessment. For all development in Flood Zones 2, 3a and 3b, for major development in Flood Zone 1, and anywhere else a site could flood from another source.
• What the assessment must cover. It should be proportionate, take in every source on and off the site, allow for climate change over the life of the development and follow the recommendations of the SFRA and the council's flood strategy.
• How the site is laid out. Where the sequential and exception tests are met, the most vulnerable uses go on the lowest-risk ground, no flood storage is lost and residual risk is answered, including safe access and egress. A site-specific Flood Emergency Response Plan is required where appropriate.
• What SD8 asks of the drainage. Greenfield runoff rates, following the London Plan drainage hierarchy. Major schemes, and any scheme in a Critical Drainage Area, submit a drainage strategy; new surface water may not drain to the foul sewer, and impermeable paving will be refused unless it is unavoidable.

The evidence behind those policies is the Level 1 Strategic Flood Risk Assessment that AECOM prepared for Lewisham, dated October 2018 and finalised in April 2019, which the plan calls the 2019 SFRA. The council's evidence page now files it among archived studies beside the 2020 Level 2 report and a February 2023 addendum, but no newer Level 1 report has been published. At more than seven years old, its maps are a starting point: the plan tells applicants to ask the Environment Agency for site-specific model outputs and to check whether the flood zones have changed. How planners use an SFRA is set out in a separate explainer. The Local Flood Risk Management Strategy 2022 to 2027 was approved by Mayor and Cabinet on 21 September 2022, and Lewisham's SuDS design and evaluation guide sets out what the council looks for in a drainage submission.

Above the borough plan, the Mayor's London Plan of 2021 remains in force for Deptford applications, with policy SI 12 on flood risk and SI 13 on sustainable drainage. Consultation on its draft successor closed on 15 October 2026, with adoption expected no earlier than 2028. Lewisham asks major schemes for the London drainage proforma, covered in our SuDS proforma guide. National policy is chapter 18 of the August 2026 NPPF, where F4 says when an assessment is needed, F5 and F6 set the sequential and exception tests, and F8 points every scheme to the 2025 National Standards for sustainable drainage.

When a flood risk assessment in Deptford is required, scheme by scheme

On the riverside and along the Creek, almost every application needs one. On the higher ground around the High Street and the Albany, which the council's evidence places in Flood Zones 1 and 2, the answer depends on the scheme. The table shows how common Deptford cases fall.

Where homes or another more vulnerable use are proposed in Flood Zone 3 away from an allocation, Lewisham also expects the sequential test. Its 2023 paper found the exception test necessary on every Deptford allocation in Flood Zone 3.

Reports we prepare for Deptford, from the Pepys Estate to Creekside

Which report a site needs depends on how close it sits to the walls and who wants the answer. Our consultants are chartered, a senior consultant signs off each report before issue, and Unda is a CIWEM Business Partner.

• Flats and workspace behind the walls. Schemes across the Evelyn and Deptford wards need a flood risk assessment for planning that answers policy SD7 and the SFRA's breach evidence.
• Creek, rain, groundwater and sewers together. On a single plot, a flood risk assessment weighs the tidal breach case against surface water, the combined sewer and groundwater above the chalk.
• Before exchange on the Pepys Estate or Creekside. Riverside flats and warehouse conversions raise lender and insurer questions that a flood risk survey for property purchase settles.
• New homes on unallocated land. Away from the allocations, housing in Flood Zone 3 faces the sequential and exception test; on the allocations the exception test still applies.
• Greenfield runoff from brownfield land. Policy SD8 asks for greenfield rates. Our drainage strategy work shows Lewisham Council how a site gets there.
• Chalk, made ground and a protection zone. Infiltration must not harm groundwater, so a surface water drainage strategy in Deptford checks the ground and the Environment Agency's view before relying on soakaways.
• After permission. When Lewisham attaches a drainage condition to a consent, we prepare the evidence for the discharge of drainage conditions.
• Levels on the Creek. The SFRA notes the Environment Agency's plan to update its Ravensbourne model; where current data do not represent a site, flood modelling can set the levels that floors depend on.
• A plan for the warning. Policy SD7 asks for a Flood Emergency Response Plan where appropriate, and a flood warning and evacuation plan ties it to the Creek to Rotherhithe Station and Ravensbourne at Deptford warning areas.
• Water close to the surface. Lewisham's evidence records elevated groundwater around Deptford, so basements and deep foundations benefit from a groundwater flood risk assessment.
• Cover for homes in Flood Zone 3. Riverside and Creekside homes sit in Flood Zone 3 behind the walls, and a flood risk assessment for insurance gives an underwriter evidence about the building itself.
• Buying allocated land. Convoys Wharf, Deptford Landings and the Creekside sites all carry the exception test, so flood risk due diligence belongs before a price is agreed.
• Studios and workshops on the Creek. North Lewisham's Creative Enterprise Zone and the Lower Creekside industrial site keep businesses in Flood Zone 3, where a business continuity flood assessment helps occupiers plan for a breach or a surcharged sewer.
• Sewer upgrades before occupation. Lewisham's site allocations ask developers to agree upgrades with Thames Water before homes are occupied, so a foul drainage strategy should confirm the connection early.
• New workspace. Deptford Landings alone is allocated 11,784 m² of employment floorspace. On commercial schemes like it, a BREEAM flood risk assessment supports the Pol 03 credits.

Flood warnings, reporting and who is responsible in Deptford

Dial 999 when a flood threatens life and 105 to report a power cut. Everything else falls to one of the six bodies in the table.

Upriver on the same bank, Rotherhithe continues the frontage towards Canada Water and Bermondsey lies beyond it. Across the Thames from Convoys Wharf is the Isle of Dogs, and Greenwich begins on the far side of the Creek. The river has its own River Thames page, and every place we cover is listed on our areas page.

Flooding in Deptford: questions from buyers, landlords and builders

Unda Consulting Limited prepares flood risk assessments, sequential and exception tests and drainage strategies for homes, workshops and development land across Deptford, from Convoys Wharf to Deptford Bridge. To discuss a site on Creekside, along Evelyn Street or near Deptford High Street, call 01293 214444 or email enquiries@unda.co.uk.