Flood Risk Assessment For Planning
Professional flood risk assessments meeting all planning requirements
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Site specific flood risk assessment compliant with the Environment Agency (EA) guidelines. Secure planning approval.
When Do You Need a Flood Risk Assessment?
A Flood Risk Assessment is required in the following circumstances:
- Your site is located within Flood Zone 2 or Flood Zone 3 as defined by the Environment Agency
- Your site is in Flood Zone 1 and the proposed development is major development (10 or more dwellings, or a site area over 0.5 hectares)
- The development involves a change of use to a more vulnerable flood risk classification, regardless of flood zone
- The site is within or adjacent to a critical drainage area or is affected by surface water flood risk
- The site is near an ordinary watercourse and the Lead Local Flood Authority (LLFA) has identified a flood risk concern
- A previous planning application was refused partly on flood risk grounds
If you are unsure whether your site requires a Flood Risk Assessment, [contact us] for a free initial assessment. We can confirm your requirements within 24 hours.
Flood Risk Assessment for Planning Applications
Urban Water prepares Flood Risk Assessments for planning applications across England, covering residential, commercial, and mixed-use developments in all flood zones. Each flood risk assessment for planning application is scoped to the specific site and development, ensuring the Local Planning Authority receives the technical evidence it needs to validate and determine the application.
Flood Risk Assessments submitted in support of planning applications must be proportionate to the scale, nature, and flood risk of the proposed development, in accordance with the National Planning Policy Framework (NPPF) and Planning Practice Guidance.
Planning requirements for Flood Risk Assessments are closely linked to a site’s location within Flood Zones 1, 2 and 3, as defined by the Environment Agency.
Urban Water prepares Flood Risk Assessments that are specifically scoped to the development, ensuring that the assessment contains the appropriate level of technical detail required by the Local Planning Authority, the Environment Agency, and the Lead Local Flood Authority.
Our approach focuses on:
- Providing sufficient evidence to support planning validation and determination
- Avoiding unnecessary analysis or modelling
- Delivering clear, policy-compliant conclusions
- Keeping costs proportionate and transparent
Each Flood Risk Assessment is tailored to the individual site and proposal, ensuring planning requirements are met efficiently and robustly.
Flood Risk Assessments Based on Development Scale
Our Flood Risk Assessments are structured according to the size and complexity of the proposed development, allowing us to provide the most appropriate level of assessment without unnecessary cost or delay.
As part of our initial screening, we review Environment Agency flood risk maps to identify river, sea, surface water, and groundwater flood risks relevant to the proposed development.
Our reports are tailored to your project’s scale and planning requirements. Our reports comply with Environment Agency (EA) guidelines and are accepted by local authorities.
What Does a Flood Risk Assessment Report Include?
Each Flood Risk Assessment prepared by Urban Water includes a complete planning-ready submission, tailored to the development and local policy requirements.
Our Flood Risk Assessments typically include:
- Site location and development description
- Review of national and local flood risk policy
- Assessment of all relevant sources of flood risk
- Assessment of surface water flood risk, including pluvial flow paths and exceedance routes where relevant
- Site-specific flood risk constraints
- Consideration of climate change flood risk allowances in line with current Environment Agency guidance
- Flood mitigation measures where required
- Clear conclusions to support planning decisions
- Review of Sequential Test requirements where applicable to support planning policy compliance
The Flood Risk Assessment is issued in a format suitable for direct submission to the Local Planning Authority as part of a planning application or discharge of conditions.
For more detail on report structure and planning requirements, see our [Flood Risk Report for Planning] page.
Types of Flood Risk Assessment We Provide
Site-Specific Flood Risk Assessment
The most common type, required for sites in Flood Zone 2 or 3. A site-specific FRA assesses all relevant sources of flood risk in detail, identifies the impact of the proposed development on flood risk, and sets out mitigation measures to ensure the development is safe for its lifetime. Required for both residential and commercial developments in medium and high-risk zones.
Sequential Test Flood Risk Assessment
Required where a Local Planning Authority or applicant needs to demonstrate that there are no reasonably available alternative sites at lower flood risk. Urban Water prepares the evidence base for the Sequential Test as part of the planning submission, working with the applicant and planning consultant to structure the assessment appropriately.
Exception Test Flood Risk Assessment
Where the Sequential Test has been satisfied but the development still falls within a higher-risk flood zone, the Exception Test requires demonstration that the development provides wider sustainability benefits and will be safe for its lifetime. Urban Water prepares Exception Test FRAs in line with NPPF Annex 3 requirements.
Greenfield and Brownfield Site Assessments
The baseline assumptions differ significantly between greenfield and brownfield sites. For greenfield sites, the assessment must demonstrate that surface water runoff rates and volumes are not increased. For brownfield sites, existing drainage infrastructure, historical flood events, and potential for betterment must all be considered.
Not sure which type applies to your site? [Get in touch] and we will confirm the appropriate scope within 24 hours.
Will This Flood Risk Assessment Be Accepted by the Council?
Our Flood Risk Assessments are prepared to meet the expectations of:
- Local Planning Authorities
- The Environment Agency
- Lead Local Flood Authorities
They are structured to address planning validation requirements and are regularly accepted as part of successful planning applications across England and Wales.
Where consultees raise comments or request clarification, we provide technical responses as part of our service to support the application through determination.
Flood Risk Assessment Costs
Fixed-price Flood Risk Assessments with no hidden fees. [See our full pricing guide →]
Common Reasons Flood Risk Assessments Are Requested
Planning authorities may request a Flood Risk Assessment where:
- A site is located within or adjacent to Environment Agency Flood Zones
- Surface water flood risk is present
- A site is affected by groundwater flood risk or within a critical drainage area
- A change of use increases flood vulnerability
- A development is classified as major development
- Flood risk information submitted is insufficient
Our Flood Risk Assessments are prepared to directly address these triggers
48-Hour Flood Risk Assessments for Planning Validation
Where timescales are critical, Urban Water can prepare and issue Flood Risk Assessments within 48 hours for suitable sites. This service supports:
- Faster planning validation
- Reduced risk of application delay
- Early identification of flood risk constraints
- Prompt responses to planning officer requests
This option is particularly suitable where Flood Risk Assessments are required urgently to support planning submission or ongoing determination.
Planning Support Included Until Determination
Urban Water’s Flood Risk Assessment service includes ongoing technical support throughout the planning determination period.
As part of our standard service, we provide:
- Responses to planning officer, Environment Agency, or LLFA queries
- Clarifications or updates to the Flood Risk Assessment where required
- Continued technical input related to flood risk matters until determination
This support is included within the agreed fee, providing certainty and avoiding unexpected additional costs during the planning process.
What Information We Need to Get Started
To prepare a Flood Risk Assessment efficiently, we typically require:
- Site address or red line boundary
- Proposed development details
- Site layout or drawings (if available)
- Target planning submission date
Where information is limited, we can still advise on feasibility and likely requirements.
When Should a Flood Risk Assessment Be Commissioned?
Flood Risk Assessments can be commissioned at different stages of a project, depending on circumstances. They are commonly required:
- Prior to planning submission to support validation
- Following a request from the planning officer
- When discharging planning conditions
- When responding to Environment Agency or LLFA objections
Early commissioning of a Flood Risk Assessment can help identify constraints at feasibility stage and reduce the risk of planning delay later in the process.
Is a Flood Risk Assessment the Only Report Required?
In some cases, a Flood Risk Assessment may need to be prepared alongside other technical reports, such as a Drainage Strategy for planning permission.
Where additional reports are required, we provide clear advice at the outset to avoid duplication or unnecessary cost.
Typical Flood Risk Assessment Timescales
Flood Risk Assessment timescales depend on the complexity of the site and the availability of information. Typical timescales are:
- Minor developments: 2–5 working days
- Major developments: 5–10 working days
- Urgent assessments: within 48 hours for suitable sites
Timescales are confirmed at appointment stage. Where planning deadlines are critical, priority delivery options are available to support validation and determination.
How do we Work?
Step 1: Initial Consultation
Contact Us & Provide Project Details. Share your development plans, drawings, and survey levels with our team.
Step 2: Preliminary Report (48 Hours)
We Analyse Flood Risk Data. We gather information from all flooding sources, including rivers, surface water, and the sea. You'll receive a preliminary report within 48 hours.
Step 3: Flood Risk Assessment & Mitigation
Site-Specific Evaluation. We assess potential flood risks and recommend resistance and resilience measures, including: Surface water management, Access & evacuation plans, Flood compensation calculations.
Step 4: Final Report Submission
Within four weeks, we provide a detailed FRA report to support your planning application approval.
Step 5: Liaising with Authorities
Planning & Compliance. We work with the Environment Agency and local authorities to ensure your development meets all flood risk legislation.
Our reports
- 48-Hour Turnaround: Receive your initial flood risk report quickly to keep your project on track.
- Flood Levels: We have the largest repository of flood levels in the UK, enabling us to deliver your project swiftly.
- Fully Compliant Reports: Designed to meet all flood risk legislation and Environment Agency (EA) requirements.
- Planning Approval Ready: Trusted by local authorities for smooth planning applications.
Why Appoint Urban Water for Your Flood Risk Assessment?
Urban Water are specialist flood risk and drainage consultants supporting developments from feasibility through to planning determination. Our Flood Risk Assessments are:
- Prepared by experienced civil engineers
- Aligned with national and local planning policy
- Proportionate, robust, and clearly presented
- Designed to support efficient planning decisions
Our focus is on delivering Flood Risk Assessments that facilitate planning approval and reduce unnecessary delay.
What Our Clients Say
What Our Clients Say
Flood Risk Assessments Prepared by Chartered Engineers
Flood Risk Assessments at Urban Water are prepared and reviewed by chartered civil engineers with specialist experience in flood risk, drainage, and planning support.
Our team holds professional registrations including:
- Chartered Engineer (CEng)
- Institution of Civil Engineers (ICE)
- Chartered Institution of Water and Environmental Management (CIWEM)
These professional standards ensure our Flood Risk Assessments are prepared in line with recognised engineering principles, current guidance, and best practice.
Argemiro Rivera, BEng(Hons) MSC CEng MICE MCIWEM C.WEM CEnv
Passionate About Flood Risk, Water Engineering & Sustainability
Arge is a Chartered Civil Engineer with specialist experience in flood risk assessment, drainage design, and planning support for residential, commercial, and mixed-use developments across the UK.
Arge is professionally registered with:
Institution of Civil Engineers (ICE) – Chartered Engineer (CEng), Member (MICE)
Chartered Institution of Water and Environmental Management (CIWEM)
Flood Risk Assessments prepared by Urban Water are aligned with national planning policy, Environment Agency guidance, and local authority requirements, and are supported through to planning determination.
Argemiro Rivera, BEng(Hons) MSC CEng MICE MCIWEM C.WEM CEnv
Passionate About Flood Risk, Water Engineering & Sustainability
Arge is a Chartered Civil Engineer with specialist experience in flood risk assessment, drainage design, and planning support for residential, commercial, and mixed-use developments across the UK.
Arge is professionally registered with:
Institution of Civil Engineers (ICE) – Chartered Engineer (CEng), Member (MICE)
Chartered Institution of Water and Environmental Management (CIWEM)
Flood Risk Assessments prepared by Urban Water are aligned with national planning policy, Environment Agency guidance, and local authority requirements, and are supported through to planning determination.
Example Flood Risk Assessment Projects
We have delivered Flood Risk Assessments for a wide range of developments, including residential, commercial, and mixed-use schemes. Recent examples include:
- Flood Risk Assessment for residential development in Flood Zone 2
- Flood Risk Assessment supporting office-to-residential change of use
- Flood Risk Assessment for mixed-use redevelopment in an urban location
- Flood Risk Assessment supporting planning approval for a major development
Our Flood Risk Assessments have supported planning applications across England and have been accepted by Local Planning Authorities and statutory consultees.
The Basildon Solar Farm project involved constructing a solar farm along and around Ford’s testing track. The solar panels were installed near the track on steep slopes and in areas already used to manage water runoff from the track. How to assess flood risk?. The planning FRA evaluated the potential for surface water flooding and its impact on the track’s drainage system.
Our flood assessment report assessed the surface water flood risk and recommended strategies for off-site flood risk management. The project also included modelling overland flows to determine how water distributes across the site.
Densworth Grove involved extending the current house and adding a new dwelling. The site specific FRA demonstrated that the development was affected by a high flood risk. Urban Water worked with the architect to meet the design goals while complying with the EA’s requirements for flood protection. They elevated the house one meter above the ground and allowed water to flow beneath it. The house features materials like hit-and-miss block and brick, along with cladding and staggered fencing, which let water move more freely.
Urban Water completed consultations with the EA and provided clear design guidance on the requirements under the National Planning Policy Framework (NPPF) for flood risk management.
The Dragon Hill development proposes to build two houses. The proposed development is affected by risk of flooding from nearby rivers. A major watercourse runs along the boundary of the site. The Strategic Flood Risk Assessment and the EA lacked flood level data for this river and objected to the application. Urban Water carried out flood risk surveys and constructed a detailed hydraulic river model using topographical surveys and LIDAR data. The complete a detailed flood risk analysis and in-depth survey of the river identified the different catchments feeding into the main river. This river flooding information with the climate change allowances, vulnerability classification determine that the exception test was not required for the site.
Hydrological and hydraulic assessments were produced for this site. Flood levels for Flood Zone 3a, Flood Zone 3b, Flood Zone 2, and Flood Zone 1 were established. These flood levels informed design changes to the new houses. As a result of this work, the development site was in compliance with the planning practice guidance and the objection from the EA was cleared.
Gainsborough Green Regeneration Project
This project involves demolishing existing garages to create 8 new dwellings.
Flood Assessment: The development is located within flood zone 2 and is at high risk of surface water flooding and groundwater flooding.
Urban Water conducted extensive consultations with the EA and the Local Council. Our flood risk consultants use the flood map for planning, flood defences data and flood modelling to create a risk mitigation commeasured for this development type. The houses were raised above potential flood levels, and a comprehensive sustainable drainage system was added to the development.
Overland flow calculations and sewer capacity assessments were also performed for this site.
Urban Water produced the evacuation plan and cleared all objections raised by the Local Council, the Lead Local Flood Authority, and the EA.
The Townsmead project involves constructing five to six dwellings.
Flooding Risk Assessment: This site is located on the border of flood zones 2 and 3. A key challenge was the unknown extent of the flood zone in relation to the development and the potential impact of flood zone 3 on evacuating the site. Our flood risk survey specialists determined the design and layout of the houses and the road.
Flood levels were obtained from the EA and correlated with the site’s LIDAR data. These levels were then checked against the Topographical Survey.
The inclusion of substantial Sustainable Drainage Systems helped control and alleviate potential surface water flooding, reducing the water flowing into the combined sewer system.
Wealden involves constructing eight new units in a greenfield area.
Assessing flood Risk: The site is affected by surface water flooding and groundwater flooding. Urban Water evaluated the potential water depth and velocity, along with the risks they pose to the users of the units. The project includes determining parameters and passing the sequential test.
The proposals provide a substantial Sustainable Drainage System to prevent increasing flood risk outside the development area. Additional measures include water resistance and resilience interventions to reduce the impact of flooding on the property.
Projects
Flood Risk Activity Permit Solutions Untitled Practice / Thames Waterfront Development
Flood Risk Assessment for Mixed-Use Redevelopment, Sorbon Estates
Battery Storage Systems Drainage Design Solutions, GTDS/Ethical Power Group
Old Foundry Close, Nancherrow, Cornwall
Questmap Business Park, Penzance, Cornwall
Woodfield Ave, London, Drainage Strategy
Not sure which assessment you need?
Choosing the right report can be complex. Get in touch with our experts—we’ll guide you through the process and recommend the best solution for your project.
Frequently Asked Questions
Our Flood Risk Assessments are prepared in accordance with national planning policy and local authority requirements. They are structured to support planning validation and are regularly accepted by Local Planning Authorities, the Environment Agency, and Lead Local Flood Authorities.
Yes. Our service includes responding to consultee queries and providing technical clarifications or updates required during the planning determination period.
In some cases, yes. Flood Risk Assessments may still be required in Flood Zone 1 where a development is classified as major development, involves a change of use to a more vulnerable use, or is affected by surface water flooding.
Yes. We regularly prepare Flood Risk Assessments at short notice to support planning submissions or respond to planning officer requests, including 48-hour turnaround where suitable.
No. When prepared correctly, a Flood Risk Assessment supports planning validation and reduces the risk of delay during determination. Our proportionate approach focuses on providing the information planners require without unnecessary analysis.
A flood risk assessment (FRA) is a detailed evaluation of potential flooding hazards for a property or development. It examines flood sources, the likelihood of flooding, and the impact on the site. An FRA is often required for planning applications in flood-prone areas.
If your site is in Flood Zone 2 or 3 or larger than 1 hectare in Flood Zone 1, you are likely required to submit a FRA for planning approval. Some councils may also request a flood risk report for developments in critical drainage areas.
You can check your flood risk by:
- Using the Environment Agency Flood Risk Map for planning.
- Checking local council flood maps.
- Consulting a professional flood risk report to assess site-specific risks and mitigation options.
A FRA is reviewed by the EA and/or the Local Planning Authority. For smaller developments, the Local Council usually assesses the FRA, while larger projects or sites in high-risk areas require EA flood risk assessment approval.
A flood risk report typically includes:
- Site location and flood zone classification.
- Flood sources (rivers, surface water, groundwater).
- Predicted flood depths and mitigation measures.
- Drainage strategies to manage water runoff.
A hydraulic model is a computer-based simulation that predicts water flow and flood levels in rivers or drainage systems. If the EA lacks river level data for your site, we can develop a hydraulic model to provide accurate flood risk calculations. Our flood risk study is used for complex surface water flood risk assessments and FRA for planning.
See how we complete our hydraulic models.
The FRA process involves several stages to ensure a comprehensive and compliant report:
- Initial Assessment (48 Hours) – We provide an initial flood risk assessment within 48 hours. While this does not include flood levels, it allows you to register your planning application.
- Flood Level Data Request – The Environment Agency (EA) releases flood level information within 20 working days, which is essential for the final report.
- Final Flood Risk Report (25 Days Total) – Once flood level data is received, we complete the full flood risk report, including mitigation strategies and drainage considerations.
- For Scotland, the Scottish Environment Protection Agency (SEPA) provides flood information instead of the Environment Agency. The process is similar but follows SEPA’s data release timelines.
Our flood risk assessment services supports you through planning until you get a response from the council or the EA.
Urban Water specialises in providing:
✅ EA FRA reports for planning applications.
✅ Flood Risk Assessments tailored to your development.
✅ Flood risk reports that meet Local Council and EA requirements.
✅ Hydraulic modelling for sites requiring in-depth analysis.
Costs depend on site size, flood zone and complexity. [View our full flood risk assessment pricing guide →]
Related planning services commonly required alongside a Flood Risk Assessment
Hydraulic River Modelling
Cost-effective river modelling for your developments, compliant with Environment Agency requirements.
Sequential and Exception Test
Our specialised planning consultants produce compliant sequential and exception reports.
Drainage Strategy
Surface water drainage design in compliance with national guidelines and lead local flood authorities.