Why a draft cannot run a flood sequential test

A sequential test flood draft can give you the policy framing, the structure and the right questions. It cannot do the test. The sequential test turns on two things no drafting tool can know: which sites were reasonably available in a defined area at a particular moment, and whether each of those sites was suitable for the development proposed. Both are facts about a local land market, and both have to be evidenced by someone who went and looked.

That is worth saying plainly, because a sequential test is one of the easiest planning documents to produce badly. The structure is simple, the policy wording is short, and a confident-sounding paragraph saying no alternative sites are available looks exactly like a completed test. It is also the reason applications get refused.

What the sequential test asks

The test comes from national policy on flood risk, with the detail set out in the Planning Practice Guidance chapter on flood risk and coastal change. Its purpose is to steer new development to areas with the lowest probability of flooding.

The sequence is: avoid Flood Zone 3, then Flood Zone 2, and locate in Flood Zone 1 if reasonably possible. Zone 3b, the functional floodplain where water has to flow or be stored in times of flood, is the most constrained of all and most development is simply inappropriate there.

Some proposals are outside the test altogether. Householder development, most changes of use and minor development do not require it, and where a site was allocated in an up-to-date development plan the test was applied at plan-making stage. Check which category you are in before commissioning anything.

Defining the area of search

The area of search is agreed with the local planning authority. That is the first point at which a drafted document runs out of road, because the agreement is a conversation and its outcome is unpredictable.

The default starting point is the administrative area of the authority. For some proposals it is narrower: a settlement, a parish, or a defined catchment where the development has to serve a particular population. For others it is wider, where the use is not tied to a place at all.

Nothing in the policy or the guidance tells you which applies to your scheme. It depends on the function of the development, the authority's strategic flood risk assessment, the plan's spatial strategy and the officer's view. Get it agreed in writing and record the exchange, because the area of search is the first thing an inspector will test on appeal.

Reasonably available sites, and why that phrase is hard

A reasonably available site is one in a suitable location for the type of development, with a reasonable prospect that it will be available to be developed within the period envisaged. Pick apart any part of that and you hit local knowledge.

Suitable location depends on the spatial strategy and on what the use needs. Reasonable prospect of availability depends on ownership, on whether the land is on the market, on options and overage agreements, on whether an existing occupier is leaving, and on what the agents in that town know about who is selling. Period envisaged depends on the applicant's programme.

So the work is desk-based research and conversations, not composition:

• Pull the authority's housing and economic land availability assessment and its brownfield register.
• Check the strategic flood risk assessment for the zones applied locally, which can be more detailed than the national mapping.
• Interrogate the Environment Agency flood map for planning for each candidate.
• Check title and marketing status for each site that survives.
• Record the date of every search, because availability is a snapshot.

A drafting tool that produced a list of sites here would be inventing them. PlanScope's drafting inserts a flag where a site-specific fact is missing rather than filling the gap, and in a sequential test that flag covers most of the substance. That is the safeguard working as intended, not a shortcoming to be edited around. The wider pattern, that drafts get the structure right and the evidence wrong, is at its sharpest in this document.

Evidence that a site was discounted properly

Each site in the area of search needs a recorded reason for rejection, and the reason has to be one the policy recognises.

Reasons that work: the site is in the same flood zone or a higher one, it is too small for the development proposed, it is in third party ownership with no prospect of release in the relevant period, or it has a constraint that cannot be overcome such as a designation or an access that cannot be formed.

Reasons that do not work: the applicant does not own it, it would be less profitable, the operator prefers the application site, or it is not on the market today without any enquiry having been made. Ownership by the applicant is the most common weak point, and it is also the easiest for an objector to spot.

The format that stands up is a schedule: site reference, area, flood zone, ownership, current status, suitability finding, availability finding, conclusion. One row per site, with a plan. A Sequential Test (Flood) presented that way can be checked in minutes, which is exactly what you want from a case officer under pressure.

Where the exception test follows

Passing the sequential test does not finish the job. For many uses in Zone 3a, and for essential infrastructure in Zone 3b, the exception test applies on top.

Its two limbs are that the development must provide wider sustainability benefits to the community that outweigh the flood risk, and that it must be safe for its lifetime without increasing flood risk elsewhere, with residual risk accounted for. The second limb is answered by the Flood Risk Assessment and its associated modelling, including the climate change allowances current at the time of submission.

Both limbs have to be satisfied. And the first limb is a judgement about this scheme in this community, which again is not something a draft can assert on your behalf.

The part a draft can usefully structure

None of this makes drafting useless. It relocates where the value sits.

A drafted sequential test gives you the policy framework stated correctly and consistently, the zone definitions, the exemptions, the correct ordering of the sequence, the exception test limbs, and a schedule layout ready to populate. It also gives you the connective text that explains why each finding matters, which is the part most consultants write from memory and the part most likely to drift out of date when national policy is reissued.

What it cannot give you is the site list, the availability evidence, the agreed area of search or the suitability judgement. Those are the same class of problem as site judgement in a design statement: they require someone to have stood on the ground and made a call.

Where the test is finely balanced, send the completed document for review by a professional with flood risk experience. PlanScope includes a professional directory for exactly that step, and for specialist technical reports qualified professional input may be required.

What to supply before drafting

The quickest way to get a usable draft is to do the research first and the writing second. Before you start:

1. Confirm whether the test applies at all, given the development type and the plan status of the site.
2. Agree the area of search with the authority in writing.
3. Complete the site search and record the date and source of each check.
4. Obtain the flood zone for the application site and every candidate from the official map, with the strategic flood risk assessment where it refines the zones.
5. Decide, site by site, whether suitability or availability is the ground of rejection, and gather the document that proves it.

Then draft. The structure is quick, the evidence is not, and a document written in that order tends to survive both validation and appeal.

Honest reporting here matters more than speed. A draft that states the policy correctly and flags every missing fact is more use than a polished document that fills the gaps with plausible text, and no draft removes the need for a site search, professional judgement or review before submission.

See PlanScope pricing for the free report, the per-report option and the Professional tier if you draft flood documents regularly.

This is general guidance, not legal advice; check the current national policy and guidance and the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.