Flood Risk Assessment in Worthing

Any flood risk assessment in Worthing starts with rain, because the town floods from surface water far more often than from the sea. It sits on a flat coastal plain between the South Downs and the Channel. Its streams and surface water sewers run through culverts to outfalls on the beach, and the tide closes those outfalls twice a day. Our consultants prepare flood risk assessments in Worthing for planning, purchase, mortgage and insurance purposes, plus sequential and exception tests and surface water drainage strategies.

On this page Worthing means the town's built-up area: the centre and seafront, Heene and West Worthing, Goring-by-Sea, Durrington and Salvington, West Tarring, Broadwater and Findon Valley, and East Worthing out to Brooklands. It is covered by the BN11, BN12, BN13 and BN14 postcode districts. Ferring and Lancing sit just outside the outline, and Worthing Borough Council, part of Adur & Worthing Councils, decides planning applications across almost all of it.

In June 2012 the storm water could not get out to sea: the outfall at the foot of King George V Avenue lay about four metres under the beach, and West Worthing's lowest streets flooded with rain and sewage.

Our flood risk consultants can talk through a Worthing site on 01293 214444 or at enquiries@unda.co.uk.

Culverts, outfalls and the tide: why rain floods Worthing

Worthing has two main rivers, and neither looks like one. The Teville Stream rises in Tarring and is piped beneath much of the town; the Ferring Rife drains West Durrington and Goring westward to the sea at Ferring. Both outfalls lock against high water, so a storm that arrives on a rising tide backs up through the drains. The Adur and Worthing flood study of July 2024 finds surface water the most frequent cause of flooding in the borough.

• Storm water in a culvert. The Local Plan describes the Teville Stream as heavily urbanised and culverted for much of its length, now acting as the channel for much of Worthing's surface water. It reappears near the Chesswood allotments and runs on in another culvert to Brooklands Lake, whose storage can be increased by taking out weir boards at its outlet.
• Gravity outfalls on the beach. In West Worthing the public surface water sewers discharge straight to the sea. When heavy rain meets high tide they cannot empty, the sewers surcharge and the water spreads sideways into the foul system.
• Some streets below the promenade. West Sussex County Council's 2012 report lists the south end of King George V Avenue and Marine Gardens among the lowest points in the town. Pumping there only moves water around the same streets; the one outlet is over the promenade.
• Rivers and rain together. Flooding along both rivers arrives with surface water in extreme rain, the 2024 study finds, as it did over and along the route of the Teville Stream in June 2012.
• Culverts need consent. Any new, altered or removed culvert on an ordinary watercourse needs consent from the county council under its LLFA Culvert Policy (version 3, September 2026), which opposes new culverting in principle.

For a site here, the route its drainage takes to the sea, and whether that route passes through a storm culvert, can matter as much as its flood zone. Our guides to main rivers and ordinary watercourses and to ordinary watercourse consent explain who controls each kind of channel, and the county's culvert policy sets out what it will and will not allow.

Search a Worthing postcode, from Goring to Brooklands

Type a Worthing postcode into the tool below to see the Environment Agency's data for rivers and the sea, surface water and reservoirs, or use our full flood risk map for anywhere in England. The coral line follows the ONS built-up area for Worthing, which runs from the edge of Ferring in the west to the Lancing boundary at Brooklands in the east, and north into Findon Valley. Expect the surface water layer to matter more than the river layer across most of the town; our note on flood zones 1, 2 and 3 explains why the two can disagree.

Ward by ward: where the 2024 flood study places the risk

The July 2024 Level 1 SFRA, prepared by JBA Consulting for both councils, reviews every Worthing ward. The seafront wards carry tidal flood zones along the front, and the Ferring Rife's flood zones reach into Northbrook and Castle in the north-west. Broadwater and Selden carry the Teville Stream's. The inland wards sit wholly in Flood Zone 1, with surface water running down dry valleys and roads.

Two further findings change the advice for sites in Flood Zone 1. Groundwater rises through the chalk at the foot of the Downs, and the study maps the highest risk of it emerging around Durrington, Goring and East Worthing (our groundwater flooding explainer covers the mechanism). It also adds tidal drainage risk zones, graded SW0 to SW4, showing where today's tide or a higher future sea would stop surface water leaving a site. The highest scores fall on the coast at Marine Crescent and West Parade, and in East Worthing.

Somerset's Lake in West Durrington, between Fulbeck Avenue and Titnore Lane, is a small raised reservoir. It was built as a fishing lake in the 1940s and holds about 14,500 cubic metres. That is below the 25,000 cubic metres at which the Reservoirs Act applies, but the SFRA treats a failure as significant for land downstream.

Storms that flooded Worthing, 1980 to 2018

Worthing's flood record is a rain record. Almost every event the councils list began with intense or prolonged rainfall overwhelming drains that empty to the sea, and in 2012 most of the streets that flooded had flooded before. The 2012 storm is the one the county investigated in detail, and its findings explain how the town's drainage fails.

1. Autumn 1980. Surface water flooded gardens, homes and roads in Durrington and Worthing, with 488 properties recorded in the county's preliminary flood risk assessment.
2. October 2000. About 20 commercial properties in the town centre flooded when surface water and highway drains could not take the rain, a failure the same record partly blames on poor maintenance.
3. 25 June 2007. Four inches of rain fell in an hour. The emergency services took more than 297 calls and Worthing Hospital flooded.
4. 10 to 12 June 2012. A storm the county rated rarer than 1 in 200 years hit hardest between Worthing and the Hampshire border. The county's investigation counted 17 affected properties in central Worthing and 19 in West Worthing. Water crossed the hospital car park, groundwater pushed through cracks in the basement and fire crews worked through the night to keep the hospital open. Homefield Park filled with water carrying sewage, and Brooklands Lake stood about 0.75 m above its weir boards at high tide.
5. 2014 and 2018. The SFRA records further flooding of roads or homes in July 2014, May 2018 and July 2018, all from surface water.

The Channel Coast Observatory's gauge on Worthing Pier logged 178 mm over the 2012 storm, a figure the county report notes the Environment Agency had not verified. The Environment Agency's warnings for Worthing are coastal, through the Rustington, Worthing and Lancing warning area; the 2024 SFRA lists no river warning area for the Teville Stream or the Ferring Rife. You can follow the nearest gauges on our live river levels map.

The seafront: shingle, groynes and the 2025 to 2026 repairs

Tidal flooding is rare within Worthing Borough, according to the county strategy the SFRA relies on, with the shingle beach and its groynes as the first line of defence. The risk that remains on the front is waves breaking over the defences and sea level rise over a building's lifetime. Worthing Borough Council is the coast protection authority for its 7.8 km of beach.

• Shingle first. The council treats the beach itself as the main defence, held in place by more than 140 timber groynes and about ten rock groynes, with a sea wall from George V Avenue to Seaview Road and three rock revetments.
• Waves over the wall. The SFRA names Marine Crescent, West Parade and Marine Parade as places where waves can come over the defences in a storm.
• Repairs just finished. The Environment Agency's works ran about 3.7 km from groyne 69 at Sea View Road to groyne 140 opposite the Brooklands car park, starting in November 2025. The council's update of 30 July 2026 puts the cost at almost £5 million and says the repairs protect the seafront and town centre for ten years.
• A longer scheme to come. The council's coastal protection page describes a separate scheme meant to protect the town for 50 years, with design alone expected to take about a decade.
• Hold the line. The shoreline management plan for Beachy Head to Selsey Bill keeps a hold-the-line policy for the whole Worthing frontage.

A defended frontage still sits in Flood Zone 3 on the planning map where the land is low, so seafront schemes have to deal with what happens if the defences are overtopped or fail. Our articles on residual flood risk, how sea defences work and shoreline management plans explain what that means for floor levels and access.

Policy DM20 and the other tests a Worthing scheme must pass

Applications in Worthing are judged against policy DM20, Flood Risk and Sustainable Drainage, in the Worthing Local Plan 2020 to 2036, which the council adopted on 28 March 2023. It spells out that every new development in Flood Zones 2 and 3 needs an assessment, minor works and changes of use included. The South Downs National Park Authority decides applications on the borough's northern edge inside the park.

• When an assessment is required (part b). On sites of a hectare or more in Flood Zone 1; for all new development in Flood Zones 2 and 3, including minor works and changes of use; and where a more vulnerable use is proposed on land at greater future risk or exposed to another source the SFRA identifies.
• What it must show (part c). That the sequential test is passed and the most vulnerable uses sit on the safest ground, the exception test where national policy calls for it, every source including residual and cumulative risk, safe access and escape (where necessary through an agreed flood warning and evacuation plan), no increase in risk elsewhere, and resistant and resilient construction.
• How surface water is managed (part d). SuDS unless clearly unsuitable, with runoff held to greenfield one-year rates for storms up to the 100-year event plus climate change where possible and never above existing flows; the 30-year storm plus climate change kept within the system; and discharge to the ground first, then a watercourse, then a surface water sewer, with a combined sewer last.
• Who looks after it (part e). Maintenance and funding arrangements for the life of the development, secured by condition or obligation.

West Sussex County Council, as Lead Local Flood Authority, reviews the surface water proposals for major applications and offers pre-application advice on them. DM20's supporting text expects SuDS to follow the county's surface water policy, the Defra technical standards and the CIRIA SuDS Manual. Under chapter 18 of the August 2026 NPPF, policy F4 sets when an assessment is needed, F5 and F6 the sequential and exception tests, and F8 expects all development to meet the 2025 National Standards for sustainable drainage.

Two council files sit behind every Worthing report: the Level 1 SFRA of July 2024 and, for site-level detail, the July 2020 Level 2 site sheets, which remain Worthing's because the December 2025 Level 2 study covers Adur only. Both are listed on the councils' flood risk evidence page, with a July 2024 sequential test method that ranks sites by their surface water risk as well as their flood zone. The 2024 study had no current model of the Teville Stream to draw on. It used the existing flood zones, with Flood Zone 2 standing in for the stream's future Flood Zone 3, and tells applicants to ask the Environment Agency for its latest information. A site beside the stream may therefore need levels of its own.

Allocated sites: what the Level 2 study found from Grafton to Fulbeck Avenue

Worthing is short of land. The Local Plan sets a minimum of 3,672 homes against an assessed need of 14,160, so it allocates every suitable site, including some at flood risk, and treats all of them as having passed the sequential test. The site sheets show what each still has to solve at application stage.

A site that is not allocated gets none of that credit. A windfall scheme in Flood Zones 2 or 3 has to show that no lower-risk site is reasonably available, while one at risk only from surface water may now skip that step if its assessment shows the development will be safe. The national guidance on the sequential test and surface water sets out how that is now applied.

Where in Worthing a flood risk assessment is required

DM20 names changes of use and minor works in Flood Zones 2 and 3 alongside new building, and reaches into Flood Zone 1 wherever the SFRA shows another source, so many small Worthing schemes need an assessment. Use this table as a first check; the Flood Map for Planning, the SFRA and the scheme itself decide the rest.

Our guides to converting a house into flats and a basement or cellar in a flood zone go into those two cases in more depth, and surface water flooding and planning explains why Flood Zone 1 is no guarantee.

Reports our consultants prepare for Worthing sites

Worthing sites reach us from developers, architects, planning consultants, homeowners, buyers and businesses. A flood risk assessment asks whether the site is safe, a sequential test asks whether it should be built on at all, and a drainage strategy shows where the water goes. Each row below gives the Worthing reason the report comes up.

• Sea, streams and the drains in one report. On the coastal plain a flood risk assessment has to weigh tidal levels and overtopping against surface water, the culverted Teville Stream or the Ferring Rife, chalk groundwater and sewer surcharge, because more than one usually applies.
• Applications under policy DM20. From a seafront change of use to a house in Durrington, a flood risk assessment for planning sets out the evidence DM20 parts (b) and (c) ask the council to see.
• Before exchange on a Worthing home. Searches flag the surface water bands in Durrington, Tarring and West Worthing, and a flood risk survey for property purchase tests what they mean for the building you are buying.
• Windfall sites at risk. Only the Local Plan allocations have passed already, so an unallocated scheme in Flood Zone 2 or 3 needs its own sequential and exception test.
• Where the water goes when the tide is in. With outfalls closed twice a day and chalk groundwater close to the surface in places, a drainage strategy has to show how a site stores water until it can leave.
• Greenfield one-year rates. A surface water drainage strategy shows runoff held to the DM20 limit for storms up to the 100-year event plus climate change, following the infiltration-first hierarchy.
• After the permission. Worthing permissions can hold back construction until a drainage scheme is approved, as one of ours did, and we prepare the discharge of drainage conditions information that clears it.
• Where no current stream model exists. The 2024 SFRA had no current model of the stream and used Flood Zone 2 as a stand-in for its future Flood Zone 3, so a site beside it may need its own levels, which flood modelling for a Teville Stream site provides.
• Chalk at the foot of the Downs. The SFRA's highest groundwater risk is around Durrington, Goring and East Worthing, and all of the Centenary House allocation sits in a high-risk band, so a basement or soakaway there may need a groundwater flood risk assessment.
• Seafront and town-centre homes. DM20(c)(iv) asks for safe access through an agreed warning and evacuation plan where needed, and the front lies in the Rustington, Worthing and Lancing warning area, so seafront schemes may need a flood warning and evacuation plan.
• Streets that have flooded before. With 488 properties flooded around Durrington in 1980 and 36 in central and West Worthing in 2012, insurance flood risk assessments help owners and buyers answer an insurer's questions about that record.
• New employment space. Decoy Farm is allocated for about 14,000 sq m and Martlets Way for about 10,000 sq m of employment floorspace, schemes where a BREEAM flood risk assessment may be part of the brief.
• Town-centre premises. About 20 commercial properties in the centre flooded from overloaded drains in October 2000, and business continuity flood assessments help occupiers plan for a repeat.
• Where the sewers are already stretched. Southern Water's records put sector BN13 2 joint highest in the two council areas for sewer flooding linked to capacity, and the Centenary House allocation ties occupation to new sewerage, so larger schemes may need a foul drainage strategy.

Flood contacts in Worthing, from Floodline to the coastal engineers

Responsibility in Worthing is split between several bodies, and the right one depends on where the water is coming from. If a flood puts anyone in danger, call 999, and call 105 if flooding has cut the power.

West Sussex County Council's local flood risk management strategy for 2025 to 2030 commits it to working with the Environment Agency on coastal flood risk in Worthing. Adur and Worthing are also the focus of the county's pilot of a rapid adaptation pathway assessment for flood and coastal risk. For the wider county picture, see our West Sussex page.

Questions Worthing applicants and buyers ask about flood risk

To discuss a site anywhere from Goring-by-Sea to East Worthing, call our chartered flood risk consultants on 01293 214444 or email enquiries@unda.co.uk. Unda Consulting Limited is a CIWEM Business Partner, and a senior consultant signs off every report. We also cover Littlehampton and Arundel to the west, Brighton and Hove to the east past the River Adur, and every area we cover.