What is a Flood Risk Assessment?

A Flood Risk Assessment (FRA) is an essential component of the site evaluation and planning submission process. It is required by the Local Planning Authority when a development is located in flood zones 2 or 3, occupies an area of one hectare or more in flood zone 1, is situated within a critical drainage area, or is on a site with potential surface water flooding.

The primary objectives of a flood risk assessment are to:

• Evaluate the potential risks and impacts of flooding on the site.
• Determine whether the proposed development will influence flooding in the surrounding area.
• Identify and recommend measures to mitigate flood risks on the development site.
• Ensure that the site will remain safe now and in the future, considering the development’s vulnerabilities and the effects of climate change.

What should be included in an FRA?

A Flood Risk Assessment (FRA) should be comprehensive and tailored to the specific site and development. Key elements that an FRA typically includes are:

1. Site Description and Location

• Location Details: Description of the site, including its size, boundaries, and topography.
• Existing Use: Current land use and any existing buildings or structures.
• Proposed Development: Details of the proposed development, including its nature, scale, and layout.

2. Flood Zone Classification

• Flood Zone Identification: Identification of the flood zone in which the site is located (e.g., Flood Zone 1, 2, or 3).
• Flood Sources: Assessment of potential sources of flooding, such as rivers, coastal, groundwater, surface water, or artificial sources like reservoirs or drainage systems.

3. Flood Risk Analysis

• Historical Flood Data: Review of any historical flood events affecting the site.
• Flood Risk Mapping: Use of Environment Agency or other relevant flood risk maps to determine flood risks.
• Climate Change Impact: Analysis of how future climate change scenarios may influence flood risks, including sea-level rise and increased rainfall.

4. Surface Water Drainage

• Existing Drainage: Description of existing drainage systems on or near the site.
• Surface Water Runoff: Assessment of how the proposed development will affect surface water runoff and the potential for increased flooding.
• Sustainable Drainage Systems (SuDS): Consideration of SuDS to manage surface water runoff, including details on their design and effectiveness.

5. Flood Risk Mitigation Measures

• Proposed Mitigation: Identification and evaluation of measures to reduce flood risks, such as raising floor levels, creating flood defenses, or altering site layout.
• Emergency Planning: Development of an emergency plan for dealing with flooding, including safe access and evacuation routes.

6. Residual Risks

• Assessment of Residual Risks: Evaluation of any remaining flood risks after mitigation measures are implemented.
• Maintenance Plan: Outline of a maintenance plan for flood defences and drainage systems to ensure they remain effective.

7. Impact on Surrounding Areas

• Impact Assessment: Consideration of how the development might affect flooding in the surrounding area, including potential off-site impacts.
• Consultation: Summary of any consultations with relevant authorities or stakeholders, such as the Environment Agency.

8. Conclusions and Recommendations

• Summary of Findings: Clear summary of the flood risks, potential impacts, and proposed mitigation measures.
• Recommendations: Specific recommendations to ensure the development is safe and complies with planning policies and regulations.

9. Appendices

• Supporting Documents: Inclusion of relevant maps, drawings, calculations, and any other supporting information that was used in the assessment.

This comprehensive approach ensures that the flood risks are thoroughly evaluated and managed, contributing to the safety and sustainability of the development.

What are the different Flood Zones in England?

In England, flood zones are designated by the Environment Agency and are used to indicate the probability of flooding in a given area. These zones are crucial for planning and development decisions. The flood zones are categorised as follows:

Flood Zone 1: Low Probability

• Description: Land assessed as having a less than 1 in 1,000 annual probability of river or sea flooding (less than 0.1% chance per year).
• Implications: Flood Zone 1 is considered the safest in terms of flood risk. Most types of development are generally acceptable in this zone, and a Flood Risk Assessment (FRA) is typically not required unless the site is over one hectare in size or has other specific risk factors.

Flood Zone 2: Medium Probability

• Description: Land assessed as having between a 1 in 100 and 1 in 1,000 annual probability of river flooding (1% to 0.1% chance per year), or between a 1 in 200 and 1 in 1,000 annual probability of sea flooding (0.5% to 0.1% chance per year).
• Implications: Development in Flood Zone 2 may require a Flood Risk Assessment to ensure that flood risks are properly managed and that the development is safe. Certain vulnerable uses, such as residential buildings, may need additional flood mitigation measures.

Flood Zone 3: High Probability

Flood Zone 3a: High Probability

• Description: Land assessed as having a 1 in 100 or greater annual probability of river flooding (1% or greater chance per year) or a 1 in 200 or greater annual probability of sea flooding (0.5% or greater chance per year).
• Implications: Strict controls are applied to development in Flood Zone 3a. An FRA is required, and developments must demonstrate that they will not increase flood risk and that appropriate mitigation measures are in place. Highly vulnerable developments are generally not permitted unless there is an exception.

Flood Zone 3b: Functional Floodplain

• Description: Land where water has to flow or be stored in times of flood, typically with a 1 in 20 or greater annual probability of flooding (5% or greater chance per year).
• Implications: Flood Zone 3b is the most restrictive zone. Development in this area is generally discouraged, with only essential infrastructure and water-compatible uses typically allowed. An FRA is mandatory, and any permitted development must demonstrate that it will remain safe and not worsen flooding elsewhere.

Flood Zone Classification Summary

• Zone 1: Low probability (less than 0.1% chance per year).
• Zone 2: Medium probability (0.1% to 1% chance per year for rivers; 0.1% to 0.5% for sea).
• Zone 3a: High probability (greater than 1% chance per year for rivers; greater than 0.5% for sea).
• Zone 3b: Functional floodplain (greater than 5% chance per year).

These zones are used by planners, developers, and local authorities to guide development decisions, ensuring that new developments are safe, sustainable, and appropriately managed in relation to flood risks.

How long does it take to complete an FRA?

The duration of a Flood Risk Assessment (FRA) can vary depending on several factors, including the complexity of the site, the scale of the proposed development, and the availability of necessary data. Generally, the process can take anywhere from 5-10 working days to a couple of months. Here’s a breakdown of what influences the timeline:

1. Site Complexity

• Simple Sites: For smaller, less complex sites located in lower-risk flood zones, an FRA might be completed in 5-10 working days.
• Complex Sites: Larger or more complex sites, particularly those in higher-risk flood zones or with multiple flood sources, could take 6-8 weeks or longer.

2. Data Collection and Analysis

• Data Availability: If the necessary data (e.g., flood maps, historical flood information) is readily available, the assessment can proceed more quickly.
• Detailed Modelling: Sites requiring detailed hydraulic modelling or climate change impact assessments may extend the timeline due to the complexity of the analysis.

3. Consultations and Approvals

• Stakeholder Consultation: Consultation with local authorities, the Environment Agency, or other stakeholders may add time, particularly if detailed feedback or additional information is required.
• Revisions and Approvals: If revisions to the FRA are needed after initial submission, this can also extend the timeline.

4. Report Preparation

• Drafting and Review: The time needed to prepare and review the final report will depend on the complexity and the level of detail required.

5. Regulatory Requirements

• Local Authority Timelines: The speed at which the Local Planning Authority processes and responds to the FRA submission can also influence the overall timeline.

In summary, while a simple FRA might be completed within a few weeks, more complex assessments can take several months, especially if detailed analysis or extensive consultations are required. It’s advisable to start the process early in the project planning stage to avoid delays. Get in touch with our Flood Risk Assessment team today to assess your property.

Who are FRA’s carried out for?

Flood Risk Assessments (FRAs) are conducted for several key stakeholders, each with a specific interest in the process and its outcomes. The main audiences for FRAs include:

1. Local Planning Authorities (LPA)

• Purpose: LPAs use FRAs to ensure that proposed developments comply with national and local planning policies regarding flood risk. They need to verify that new developments are safe, sustainable, and do not exacerbate flooding elsewhere.
• Role: The LPA reviews the FRA as part of the planning application process and uses it to make informed decisions about granting or denying planning permission.

2. Developers and Architects

• Purpose: Developers and architects rely on FRAs to understand the flood risks associated with a site and to design developments that minimise these risks.
• Role: The FRA informs site design, layout, and construction methods, ensuring that the development meets regulatory requirements and is safe for future occupants.

3. Environment Agency (or equivalent regulatory body)

• Purpose: The Environment Agency (or its equivalent in other countries) uses FRAs to assess how a development might impact flood risks in the area and to ensure compliance with broader flood risk management strategies.
• Role: The agency may provide guidance, set requirements for mitigation measures, or object to a development if the FRA indicates significant risks that are not adequately addressed.

4. Property Owners and Future Occupants

• Purpose: Property owners and future occupants need assurance that the site has been properly assessed for flood risks and that appropriate measures have been taken to ensure safety.
• Role: The FRA helps to ensure that their property will be safe from flooding now and in the future, protecting their investment and well-being.

5. Insurance Companies

• Purpose: Insurers may use FRAs to assess the flood risk of a property when determining insurance premiums and coverage terms.
• Role: The findings of an FRA can influence the cost and availability of flood insurance for a development.

6. Local Communities

• Purpose: Local residents and communities are concerned with the potential impact of new developments on local flood risks.
• Role: An FRA helps to reassure the community that the development will not increase flood risk in the area and that any concerns about flooding have been addressed.

7. Consultants and Engineers

• Purpose: These professionals conduct the FRA and are responsible for providing accurate, detailed assessments and recommendations.
• Role: They analyse flood risks, propose mitigation measures, and ensure that the development complies with all relevant regulations.

Overall, FRAs are essential for ensuring that all stakeholders are informed about flood risks and that appropriate measures are in place to mitigate those risks.

Will I need an FRA?

In addition to being a requirement by the Local Planning Authority, Flood Risk Assessments (FRAs) play a crucial role in managing flood risks, helping to minimise the dangers posed to people and the environment. Moreover, FRAs aim to reduce the likelihood of human and socio-economic losses. Call us today to book your Flood Risk Assessment.