Where flood risk applies in Lewes District
The council's Level 1 Strategic Flood Risk Assessment (December 2024) sets out the main sources:
- Newhaven and the tidal OuseIn December 2013 tidal flooding affected 50 to 60 properties in Newhaven, the A26 and the Lewes to Seaford railway. The Newhaven Flood Alleviation Scheme, fully operational since summer 2021, now protects around 430 homes and 390 businesses to a 1 in 200 year standard allowing for climate change.
- Seaford and the coastSeaford's frontage is protected by a sea wall with a recorded standard of protection of 1 in 100 years, rising locally to 1 in 1,000 years. Sea levels in the South East are expected to rise by about 1.2 metres between 2000 and 2125 under the higher central allowance.
- The River Ouse and its tributariesMuch of the Ouse's upper catchment is not protected by defences. In October 2000 the middle and lower Ouse overtopped its banks from north of Spithurst to Southease, and in January 2009 its capacity was again exceeded down to South Malling.
- Surface water and groundwaterHigh groundwater levels contributed to the autumn 2000 floods, some of the worst recorded in Sussex, when ordinary watercourses, surface water and highway drains were overwhelmed. Peacehaven, Newhaven and Seaford have their own Surface Water Management Plan.
What Lewes District Council will look for
Lewes District Council applies the national tests in NPPF Chapter 18 and the Planning Practice Guidance, supported by its Strategic Flood Risk Assessment. A Sequential Test submitted with a Lewes District application should normally:
- Confirm the flood zone and vulnerabilityUse the current Environment Agency Flood Map for Planning and the NPPF Annex F vulnerability class for the proposed use.
- Justify the area of searchNational policy says the area of search should reflect the catchment for the type of development and the need it serves. Lewes District Council plans the district outside the South Downs National Park: the coastal towns of Newhaven, Peacehaven, Seaford and Telscombe and the villages north of the Downs. For smaller schemes a narrower area matching the settlement served is often more defensible than the whole planning area.
- Assess the council's own sources of sitesthe Lewes District Land Availability Assessment 2025/26, with the council's own conclusions on each site, including the adopted Local Plan and neighbourhood plan allocations, and the Brownfield Land Register are the obvious places to start, and omitting them is a common reason for challenge.
- Evidence every discounted siteWhere an alternative is ruled out as unsuitable, too small or not available in a similar timeframe, give the reason and the evidence. Ownership alone is not enough.
- Screen for the Exception TestState whether the Exception Test applies under Annex F Table 3, and if it does, provide it, drawing on the site-specific flood risk assessment.
Lewes District-specific pitfalls
- The National Park boundaryLewes town and much of the Downs are in the South Downs National Park, which is a separate planning authority. Our Lewes reports search the district outside the National Park; tell us if your scheme's catchment crosses the boundary.
- Reliance on defencesNewhaven and Seaford are defended, but the Sequential Test uses flood zones as if the defences were not there. The defences matter for the site-specific flood risk assessment, not for choosing between sites.
- Sites the council has not ruled outThe Land Availability Assessment marks many sites as potentially deliverable or developable. We treat them as reasonably available, as the council has not ruled them out, and show the council's reasoning so you can respond to it.
- A new Local Plan in preparationThe new Lewes Local Plan to 2040 is not yet at examination, so its proposed allocations are not used. The adopted Local Plan and neighbourhood plan allocations are included through the Land Availability Assessment.
Fixed-fee Sequential Tests for Lewes District
We have built our Lewes District Sequential Test on published Environment Agency and Lewes District Council data. Plot your site on our Lewes District Sequential Test page and we'll deliver a submission-ready report within 24 hours of payment for £300. Exception Tests are £450 within 48 hours.
New to the subject? Start with our general guide: what is a flood risk Sequential Test? We also cover other council areas at the same fixed fee. For wider planning help, see planning consultants in Lewes District.
Source: Lewes Level 1 Strategic Flood Risk Assessment (AECOM, December 2024).
Sequential Test guides for other council areas
Runnymede · Spelthorne · Oxford · Dover · Medway · Bristol · Manchester · Birmingham · Chelmsford · Gateshead · Tameside · East Riding of Yorkshire · Wigan · York · Plymouth · Lichfield · Hull · Northumberland
Frequently asked questions
Does Lewes District Council require a Sequential Test?
Yes, for most development in Flood Zones 2 and 3, in line with national policy. Some minor development and most changes of use are exempt, and sites allocated in the local plan may not need the test repeated.
What area of search should I use in Lewes District?
National policy says the area of search should reflect the catchment for the type of development and the need it serves. Lewes District Council plans the district outside the South Downs National Park: the coastal towns of Newhaven, Peacehaven, Seaford and Telscombe and the villages north of the Downs. For smaller schemes a narrower area matching the settlement served is often more defensible than the whole planning area. The reason must be explained in the report.
Do flood defences mean I don't need a Sequential Test?
No. Flood zones for the Sequential Test are assessed without defences. Defences are taken into account in the site-specific flood risk assessment and the Exception Test, not the Sequential Test.
How much does a Sequential Test cost in Lewes District?
Our fixed fee for a Lewes District flood risk Sequential Test or alternatives assessment is £300, delivered within 24 hours of payment. An Exception Test is £450, delivered within 48 hours.
This guide is general information for applications in England and is not advice on your specific project. Requirements differ in Wales, Scotland and Northern Ireland, and every council publishes its own local validation list, so always check the detail with your local planning authority.