Pre-Application Advice on Flood Risk: When and How to Use It

Submitting a planning application for a flood-constrained site without first testing the water with the relevant regulatory bodies is a gamble. Pre-application advice from the Environment Agency (EA), the Lead Local Flood Authority (LLFA), and — where relevant — Internal Drainage Boards (IDBs) gives you a window into how your proposal will be assessed before you commit the time and cost of a full application.

But the pre-application landscape is not straightforward. Services vary in cost, availability, and usefulness depending on which body you are engaging with and where your site is located. This article explains when and how to use pre-application advice on flood risk, what to submit, and how to translate the response into a stronger planning application.

Pre-Application Advice from the Environment Agency

The EA is a statutory consultee on planning applications involving flood risk. Its role at the pre-application stage is to provide early guidance on whether a development is likely to face objection on flood risk grounds and what evidence will be needed to address its concerns.

Free vs Charged Services

The EA’s pre-application service has changed significantly in recent years. The key distinction is between standing advice and bespoke consultation.

Standing advice remains free. The EA publishes standing advice for minor developments in Flood Zones 2 and 3, which sets out generic requirements for flood risk assessments and mitigation measures. This is publicly available and does not require any engagement with the EA — it is a set of standard guidelines that LPAs apply to smaller-scale proposals.

Bespoke pre-application consultations for developments in Flood Zones 2 and 3 are now charged. The EA introduced charges for its enhanced pre-application service, and the cost varies depending on the complexity of the proposal. For straightforward consultations — a single site with a clear question about flood risk — the charge is typically in the region of GBP 600. For more complex proposals involving multiple flood sources, bespoke flood modelling, or strategic-scale development, the charge can rise to GBP 1,200 or more.

The charging threshold is not defined by a simple site area or unit count. Rather, it is the nature and depth of the advice being sought that determines the cost. If you are simply asking the EA to confirm the flood zone classification or point you to available data, that is at the lower end. If you are asking for a detailed review of preliminary FRA findings, proposed compensatory storage, or a draft breach analysis, the cost will be higher.

What to Include in a Pre-App Request to the EA

A good EA pre-application request is not a vague enquiry. The more focused and evidence-based your submission, the more useful the response will be. As a minimum, include:

A site location plan. At an appropriate scale (typically 1:1,250 or 1:2,500), showing the site boundary, any watercourses, and the surrounding flood context.

Preliminary FRA findings. If you have already carried out initial flood risk screening — including a review of the EA’s Flood Map for Planning, historical flood data, and flood zone mapping — summarise the findings. The EA will provide a more useful response if it can see that you have already done the groundwork.

Proposed development description. A concise description of what you intend to build, including the vulnerability classification of the proposed use (this is critical for the Sequential and Exception Tests).

Proposed mitigation measures. If you have formed a view on the likely mitigation — finished floor levels, compensatory storage, safe access and egress routes — set these out. The EA can then comment on whether they are likely to be acceptable.

Key questions. Frame your request around specific questions. For example: “Will the EA require bespoke hydraulic modelling for this site?” or “Is the proposed finished floor level of 300mm above the 1% AEP plus climate change flood level sufficient?” Specific questions produce specific answers.

What You Get Back

The EA’s pre-application response will typically set out:

• Whether the EA is likely to object to the proposed development in principle
• What level of FRA is expected (desktop, detailed, or modelled)
• What flood data is available and whether bespoke modelling is required
• Whether the proposed mitigation approach is likely to be acceptable
• Any specific concerns about the proposal (e.g., loss of floodplain storage, inadequate safe access)

The response is advisory, not binding. The EA’s position may change between pre-application and formal consultation if circumstances change — for example, if the Flood Map for Planning is updated or if new climate change allowances are published. But in practice, if you address the points raised in the pre-app response, the EA is unlikely to raise new objections at the formal stage.

Pre-Application Advice from the LLFA

The LLFA is the statutory consultee for surface water drainage on major developments (10 or more dwellings, or sites of 1 hectare or more). Its role is to assess whether the proposed surface water drainage strategy is acceptable, including the SuDS design, discharge rates, and attenuation provisions.

A Patchwork of Services

Unlike the EA, which operates a relatively consistent national service, LLFA pre-application services vary enormously by authority. This variation is one of the most common sources of frustration for developers and consultants.

Some LLFAs charge for pre-application advice. Fees of GBP 500 or more are not unusual, particularly for major developments. These charged services typically provide a written response within a defined timescale (often 4-6 weeks) and may include a meeting.

Some LLFAs offer free initial meetings. Particularly for large or complex sites, some LLFAs will hold a free preliminary meeting to discuss the drainage approach before a formal submission. These meetings can be extremely valuable — they give you a direct line to the officer who will review the application and allow you to agree the design approach in principle.

Some LLFAs have no formal pre-application service at all. In these areas, you may need to rely on the LLFA’s published guidance and generic requirements. Check the LLFA’s website for any local design guides or supplementary planning documents relating to surface water drainage.

Making the Most of LLFA Pre-App

When an LLFA pre-application service is available, use it to resolve the key questions early:

• Discharge rate. What greenfield runoff rate is acceptable? Some LLFAs accept QBAR, others require the 1-year greenfield rate, and some accept a pragmatic minimum (e.g., 2 l/s) for brownfield sites where limiting to greenfield rates is impractical.
• Climate change allowances. Which rainfall uplift should be applied? The current national guidance provides a range, and some LLFAs have a preference.
• SuDS hierarchy. What evidence of infiltration testing is required before non-infiltration solutions will be accepted? Some LLFAs insist on BRE 365 testing before they will approve any attenuation-based scheme.
• Adoption and maintenance. What are the LLFA’s expectations for long-term SuDS maintenance? Some LLFAs expect adoption by a management company with a commuted sum; others expect SAB (SuDS Approving Body) adoption where applicable.

Pre-Application Advice from Internal Drainage Boards

If your site falls within an Internal Drainage Board (IDB) area, the IDB is an important consultee for both flood risk and drainage. IDBs manage water levels in low-lying areas and have byelaw powers over development within their districts.

Many IDBs offer informal pre-application discussions, and this is strongly recommended for any development in an IDB area. Key issues to discuss include:

• Consent for discharge. Any increase in surface water discharge to an IDB watercourse or drain requires land drainage consent under the Land Drainage Act 1991. The IDB will advise on the maximum discharge rate and any contributions required.
• Board rates and development levies. Development in an IDB area may attract charges for increased surface water runoff.
• Byelaw compliance. IDBs typically require a minimum standoff distance (often 9 metres) from the top of bank of any maintained watercourse. This can have significant implications for site layout.

IDB pre-application engagement is often overlooked, but failure to account for IDB requirements can cause serious delays at the application stage. IDB objections are taken seriously by LPAs, and addressing them retrospectively is far more expensive than incorporating them from the outset.

Pre-App vs Formal Consultation: Understanding the Difference

It is important to understand that pre-application advice is fundamentally different from the formal consultation that occurs during a planning application.

Pre-application advice is informal, advisory, and without prejudice. It represents the consultee’s view at a point in time based on the information available. It does not bind the consultee to a particular position when the formal application is submitted. It does not constitute a decision.

Formal consultation occurs after a planning application is submitted. The LPA formally consults the EA, LLFA, and other statutory consultees. Their responses carry significant weight in the LPA’s decision-making — an EA objection on flood risk grounds will almost certainly result in refusal unless the objection can be resolved. Formal consultation responses are public documents and form part of the planning file.

The practical implication is clear: pre-app gets you the direction of travel, while formal consultation is the real test. But the two are connected. If you follow the advice given at pre-app stage, the formal consultation response should hold no surprises.

When Is Pre-App Essential?

Pre-application advice is not always necessary. For straightforward developments in Flood Zone 1 with no surface water risk, there is little to be gained from engaging the EA or LLFA before submission. But for more complex sites, pre-app is not just useful — it is essential.

Pre-App Is Essential When:

• The site is in Flood Zone 2 or 3 and the EA will be consulted on the application. Getting EA buy-in before submission dramatically reduces the risk of objection.
• Bespoke flood modelling is needed. If the site requires hydraulic modelling, agree the modelling approach and parameters with the EA before investing in the modelling work. The cost of repeating a model because the EA does not accept the methodology far exceeds the cost of a pre-app consultation.
• The drainage strategy is complex. Sites with multiple discharge points, restricted infiltration, or brownfield constraints benefit from LLFA engagement before the strategy is finalised.
• The development is in an IDB area. As discussed above, IDB requirements can fundamentally affect site layout and viability.
• The Sequential or Exception Test is in play. If your site requires the Sequential or Exception Test, getting the EA’s view on the test methodology and the proposed mitigation before submission is invaluable.
• There is a history of flooding. Sites with a documented flood history will attract close scrutiny. Pre-app allows you to understand the regulatory concerns and address them proactively.

Pre-App Is Optional When:

• The site is in Flood Zone 1 with no surface water risk
• The development is minor and falls within the EA’s standing advice
• The LLFA’s published guidance is clear and the drainage approach is straightforward
• A recent, relevant pre-app response already exists for the site (e.g., from a previous application)

How Pre-App De-Risks Your Application

The fundamental value of pre-application advice is that it converts unknowns into knowns. A well-managed pre-app process achieves several things:

It identifies showstoppers early. If the EA is going to object to the principle of development on flood risk grounds, better to know before you spend tens of thousands on a full FRA, drainage strategy, and planning application.

It agrees the evidence requirements. Pre-app establishes what level of assessment is needed, what data sources to use, and what modelling approach is acceptable. This prevents abortive work.

It builds regulatory relationships. Pre-app gives you a named officer at the EA or LLFA who understands your site and your proposal. This makes the formal consultation process smoother and faster.

It strengthens the FRA. An FRA that can demonstrate it has been prepared in accordance with pre-application advice from the EA is significantly more credible than one prepared in isolation.

As we discussed in our BESS project in Barrhead, early engagement with regulators was key to navigating a complex flood risk and planning context.

How Aegaea Can Help

Aegaea manages the pre-application process on your behalf. We prepare the pre-application submissions, coordinate with the EA, LLFA, and IDBs, and interpret their responses to inform the flood risk assessment and drainage strategy. We know which questions to ask, how to frame them, and how to translate the answers into a robust technical case for your planning application.

If you are planning development on a flood-constrained site and want to de-risk the process from the outset, contact us for a no-obligation discussion.