Flood Risk Consultancy Services

A flood risk consultant works out how flooding could affect a site or a property, and how to deal with it, then puts that in a report the people making the decision will accept. Unda is a chartered flood risk and drainage consultancy, and this page explains what our flood risk consultants do, when you need one, and how we work, so you know what you are getting before you commission anything. We produce planning-ready assessments and the mitigation that gets awkward sites approved, for developers, planning consultants, architects, landowners, homebuyers and insurers across England and Wales.

A Senior Flood Risk Consultant oversees and signs off every project we deliver, whatever its size, and we reply to every quote request within 60 minutes. We have completed more than 5,000 assessments since 2014, and we are known for scaling the work to the actual risk rather than running every site through the same template.

Most sites that look difficult are not impossible; they are usually just under-assessed.

What does a flood risk consultant do?

A flood risk consultant establishes how likely a site is to flood, how bad that flooding would be, and what can be done to manage it so the development is safe and the application stands up. The job is partly technical and partly about knowing what a planner, the Environment Agency or a Lead Local Flood Authority actually needs to see before they will sign something off.

Good practice starts with every source of flooding, not just the obvious one. National screening maps are only a starting point: they describe broad areas rather than individual plots, so a consultant reads the detailed Environment Agency and Natural Resources Wales data for your specific site and works through all six sources of flooding. Sites near a watercourse are checked against the relevant river data, and a rising water table is pinned down with a groundwater assessment. This matters because a site can sit comfortably outside the mapped river floodplain and still be at real risk from surface water or groundwater, which is exactly the kind of thing a broad screening layer misses and an experienced consultant does not.

When the published maps are not detailed enough to settle a decision, we model the flood levels and flow routes ourselves rather than defaulting to the worst case on a broad-brush layer. That in-house modelling capability is what separates a firm that can only report what the maps say from one that can actually argue a site's real risk. We then design proportionate mitigation, covering finished floor levels, safe access and egress, resilience measures, compensatory storage and drainage, and set it out in a report that planners and regulators will accept. A consultant worth having also stays involved after the report goes in, answering objections and questions before they turn into delays, whether that is a Flood Risk Assessment for planning, the Sequential and Exception Tests, or a flood risk survey for a purchase.

When do you need a flood risk consultant?

Most clients come to us for one of a handful of reasons. Each points to a slightly different piece of work, so the first job is usually matching your situation to the right assessment.

• A planning application. A site in Flood Zone 2 or 3, one hectare or more in Flood Zone 1, or anywhere surface-water risk is flagged, which is far more common since the 2025 Planning Practice Guidance update. This can call for a Flood Risk Assessment for planning, a Flood Consequence Assessment in Wales, or Sequential and Exception Test reports.
• Buying a home. An independent, property-specific flood risk survey before you commit, especially where a search has come back with a high-risk flag.
• Insurance. Property-level evidence to support cover and underwriting, where an insurer has raised concerns or a premium has jumped.
• BREEAM. An assessment built to support your BREEAM Pol 03 credits.
• Due diligence and business continuity. Flood risk evidence for acquisitions, portfolios and resilience planning, where the question is exposure rather than a single application.

If you are not sure which of these fits, that is fine; working out the right scope is part of the job, and it is better to have that conversation before a report is commissioned than after. You can read our fuller guide on when a flood risk assessment is needed if you want to check your own situation first.

What to look for when choosing a flood risk consultant

Anyone can call themselves a flood risk consultant, and the quality of report the Environment Agency and Lead Local Flood Authorities receive varies widely. A few things separate a report that clears the first review from one that comes back with questions. It is worth checking for these before you instruct anyone.

• Chartered, accountable people. Membership of a recognised body such as CIWEM, and named consultants who put their name to the advice rather than an anonymous byline.
• Genuine independence. A consultant assessing the risk honestly, not talking a scheme up or down to suit anyone; the point of the report is that a regulator can rely on it.
• In-house modelling. The ability to model flood levels and flow routes when the maps are not enough, rather than stopping at a screening layer and hoping.
• Regulator familiarity. Day-to-day experience of what the EA, the LLFAs and Local Planning Authorities expect, so the report is pitched correctly first time.
• Proportionate scoping. An assessment matched to the actual risk, so you are not paying for modelling a low-risk site never needed, nor under-scoping one that did.

Expertise matters more here than it looks, and a thin or generic report can cost more in delay than a proper one costs to produce. We have written before about why a flood risk assessment is a job for a specialist, and why an automated report will not satisfy a planner.

How we work

Every project is different, but a typical instruction runs through the same stages, and a Senior Flood Risk Consultant signs off the result at the end.

1. Free appraisal and quote. You tell us about the site, we tell you what is actually needed and what it will cost, and we reply within 60 minutes on a working day.
2. Data and desk study. We gather the relevant Environment Agency or Natural Resources Wales data, the planning context and the site information, and read them against your specific plot rather than the wider area.
3. Assessment and, where needed, modelling. We assess every source of flooding and, where the published maps cannot settle it, model the levels and flow routes in-house.
4. Mitigation design. We design proportionate measures: finished floor levels, access and egress, resilience, compensatory storage and drainage.
5. Report and sign-off. We produce a clear, regulator-ready report, signed off by a Senior Flood Risk Consultant.
6. Support through determination. We stay involved, answering the Environment Agency, the LLFA or the planners so questions do not become refusals.

We aim to meet any reasonable deadline and can expedite urgent work; timescales are confirmed when we quote, once we can see what the site actually needs.

Is Unda the right flood risk consultant for your project?

This page covers flood risk consultancy in general. If you already know the specific piece of work you need, it is quicker to go straight to it. Here is where to head next:

• Developing in England? Start with a Flood Risk Assessment for planning, and see our NPPF guidance.
• Developing in Wales? You will likely need a Flood Consequence Assessment, guided by our TAN15 advice.
• Facing the Sequential Test? See Sequential and Exception Test reports.
• Buying a home? A flood risk survey for a property purchase is the right report.
• Sorting insurance? See our Flood Risk Assessment for insurance.
• Chasing BREEAM credits? Go to Flood Risk Assessment for BREEAM.
• Need drainage, not just flood risk? See sustainable drainage strategy and design, discharge of drainage conditions and preliminary drainage design.
• Looking for a role, not a report? We are a small consultancy that hires; meet the team on our About page rather than starting a quote.

Still not sure which you need? That is exactly the kind of thing a five-minute conversation sorts out, so get in touch and we will point you the right way.

The difference an experienced consultant makes

Flood risk work rewards judgement, and judgement comes from having done it many times before. The Environment Agency and Natural Resources Wales datasets are not a simple yes or no; they are layers of modelling, assumptions and caveats that have to be read in the context of a particular plot. Knowing when a site genuinely needs detailed flood modelling and when a proportionate assessment will do, where a floor level or a compensatory storage volume will satisfy a case officer, and how to frame a Sequential Test argument that holds up, is the part you are really paying a consultant for. Get it wrong and the cost is not just the report; it is weeks of delay, a fresh objection, or a refusal.

Our consultants have spent careers on this. Between them they have delivered more than 5,000 assessments since 2014, they are chartered through CIWEM, and they model in-house using industry-standard software rather than farming the technical work out. That experience shows most on the sites other people struggle with, and it is why developers, insurers and homeowners come back to us. It is also why we are asked to act as expert witnesses and to comment for the national press on flood risk.

The value of an experienced consultant is not the report itself; it is the approval the report unlocks and the delays it avoids.

Experience also keeps costs honest. A consultant who has seen thousands of sites can scope the work to the real risk, so a straightforward site is not over-assessed and a difficult one is not under-cooked. Whether the job is an FRA for planning, a Flood Consequence Assessment in Wales, an assessment for BREEAM, or a flood risk assessment for insurance, the same principle applies: the right scope, done properly the first time, by someone who has been here before.

Why choose Unda

The flood risk market is crowded, and a lot of it is thin. What clients tend to value about working with us comes down to a few things.

• Chartered and accredited. Our consultants are members of CIWEM, including Chartered Water and Environmental Managers (C.WEM MCIWEM), and Unda is a CIWEM Business Partner.
• A real track record. More than a decade in flood risk and over 5,000 assessments since 2014, every one signed off by a Senior Flood Risk Consultant.
• Difficult sites approved. We are known for getting awkward sites through, and we scale each assessment to the actual risk so you are not paying for scope you do not need.
• Regulator relationships. We work with the Environment Agency, Lead Local Flood Authorities and Local Planning Authorities week in, week out, and we know what each expects to see.
• A recognised voice. The national press asks us to comment on flooding and climate resilience, including The Telegraph, the Daily Express and Farmers Weekly, and we act as expert witnesses on flood risk and drainage.
• Rated by clients. Our clients rate us 5 stars on Google.

Meet some of our consultants

Our reports are written and signed off by named, qualified people, not an anonymous production line. A few of the consultants you might work with:

• Edward Bouët BSc (Hons). Co-founder, with more than 20 years in flood risk and drainage.
• Jackie Stone BSc (Hons) MSci (DIC). Co-founder, over 30 years' experience, a CIWEM Environmental Partner.
• Antony Rousou BSc (Hons) C.WEM MCIWEM. Chartered, leading our drainage and SuDS work.
• Emma Jeffery MSci (Hons). Senior consultant specialising in hydrological and hydraulic modelling.

You can meet the full team on our About page, and see where our experts feature in the press on our In the Media page.

Our flood risk and drainage services

Whatever your site needs, it sits within the same consultancy, so the flood risk and drainage work stay joined up rather than handed between firms.

• Flood risk. FRA for planning, Flood Consequence Assessment for Wales, Sequential and Exception Test reports, flood modelling and groundwater flood risk.
• Property and compliance. Flood risk survey for a property purchase, FRA for insurance and FRA for BREEAM.
• Drainage. Sustainable drainage strategy and design, discharge of drainage conditions and preliminary drainage design.

If you would rather browse by topic, the flood risk assessment hub pulls the whole picture together.

Recent results

We handle single dwellings and large multi-site schemes alike, and the value of a good consultant shows most on the sites that first looked unpromising. Recent results include an Environment Agency objection withdrawn on a mixed-use scheme in Flood Zones 2 and 3, an EA no-objection for development in a tidal Flood Zone 3, a Sequential Test accepted for a London residential scheme, and a Flood Zone 2 conversion approved despite surface-water risk.

A well-argued assessment can turn an objection into a no-objection; that is usually where a consultant earns their fee.

There is more on our projects page.

Working across England and Wales

We work throughout England and Wales, and local knowledge is part of what makes an assessment land. The way a Lead Local Flood Authority interprets its own standards, the history of a particular watercourse, the quirks of a council's validation list: these vary from place to place, and a consultant who knows them saves you a round of objections. To make that easier to check, we publish flood risk information three ways.

• By area. Our area pages cover flood risk and planning context town by town and county by county.
• By river. Our river pages set out the flood risk posed by individual watercourses.
• By local authority. Our local authority pages explain what each council and LLFA expects on flood risk and drainage.

You can also check a site yourself with our free flood risk map postcode checker and our live river levels map, or the government's own check your long-term flood risk service, before you speak to us.

Frequently asked questions

Talk to a flood risk consultant

If you need a quote or just want to talk something through, one of our experienced Flood Risk Consultants will get back to you within 60 minutes on a working day. Call +44 (0) 1293 214444, email enquiries@unda.co.uk, or start a quote and tell us about your site.