Development and Flood Risk SPD - Practical Guidance for Applicants and Agents

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The Development and Flood Risk Supplementary Planning Document (SPD) adopted on 27 July 2022 aims to help developers and their agents to submit appropriate flood risk and flood risk management information with planning applications in Ipswich. The aim is to manage and mitigate potential flood risk in the location and design of development. 

This new version of the Development and Flood Risk SPD supersedes and replaces the 2016 version of the SPD previously in use. This webpage helps to clarify applicants’ and agents’ responsibilities in respect of the Development and Flood Risk SPD.

Why is Action Needed?

  • Flooding from rivers, estuaries and the sea poses a risk to people and can significantly affect their mental health, as well as causing significant economic impacts.
  • The National Planning Policy Framework (NPPF) requires inappropriate development in areas at risk of flooding to be avoided by directing development away from areas at highest risk. Where development is necessary in such areas, the development should be made safe for its lifetime without increasing flood risk elsewhere.
  • The Ipswich Strategic Flood Risk Assessment (SFRA) was updated in October 2020 as required by the NPPF. It is an evidence document which responds to recent changes such as the completion of the Ipswich tidal barrier in 2019, a new hydraulic model for the River Gipping and updated climate change allowances published by the government.
  • Adopted Ipswich Local Plan Policy DM4 Development and Flood Risk of the Core Strategy and Policies Development Plan (DPD) Review identifies the policy requirements for planning applications in relation to flood risk.

The Development and Flood Risk SPD adds further detail to the policies in the Ipswich Local Plan 2022. 

How to use the SPD

The SPD guides people applying for planning permission through the ‘flood risk management hierarchy’, which is shown in the diagram below:


Step 1 - Establish whether the development needs planning permission

Planning permission is required if the work you want to carry out meets the statutory definition of development. This is explained in Chapter 4 of the Development and Flood Risk SPD, which also provides links to further sources of information. Some types of works are exempted but may need other approvals, such as Building Regulations.

The Town and Country Planning (General Permitted Development) (England) Order 2015 allows certain building works and changes of use to be carried out without having to make a planning application. These are called ‘permitted development’. It should be noted that even where some types of development are classed as permitted development, applicants may be required to apply for a permitted development prior approval to the local planning authority, which allows the Council to take account of flood risk in the same way as development that does require a planning application.

Prior to submitting a planning application, applicants and agents are strongly advised to enter into pre-application discussions with:

  • Ipswich Borough Council as the Local Planning Authority;
  • Suffolk County Council as the Lead Local Flood Authority; and
  • the Environment Agency.

The Suffolk Resilience Forum website also sets out guidance on ‘Building in flood prone areas.

Step 2 - Establish whether the Sequential Test is needed

The Sequential Test is a decision-making tool designed to ensure that sites at little or no risk of flooding from any source are developed in preference to sites at higher risk. This will help avoid the development of sites that are inappropriate on flood risk grounds.

Chapter 5 of the Development and Flood Risk SPD explains when a development proposal will need to be subject to the Sequential Test.  For example, a Sequential Test must be undertaken as part of the planning application process if the development site falls within Flood Zones 2 or 3 and a Sequential Test has not already been completed for development of the same type at the site (e.g. through its allocation in the Local Plan). 

Check your proposal against Chapter 5 of the SPD to establish whether the Sequential Test needs to be undertaken. If it does need to be undertaken, Chapter 5 provides guidance as to how to approach it.

Step 3 - Establish whether a Drainage Strategy is needed

A Drainage Strategy is used to identify the best way to manage water discharged from the development. It would include consideration of the physical conditions on the site such as soil type, topography and underlying geology, and which sustainable drainage solutions are policy compliant and most appropriate to the conditions.

The National Planning Policy Framework requires that all major development incorporates Sustainable Drainage Systems (SuDS) unless there is clear evidence that this would be inappropriate.

The Flood and Water Management team at Suffolk County Council (SCC) is a statutory consultee for surface water drainage proposals for major developments.

Check the standing advice on the SCC website, available at:  The Flood and Water Management team at Suffolk County Council also strongly encourages developers to contact them as early as possible in the planning process for advice on how to produce an application which achieves the 4 pillars of SuDS - water quality, water quantity, biodiversity and amenity - and is also acceptable from a flood risk perspective.

Refer to the Chapter 6 of the Development and Flood Risk SPD to identify the circumstances in which SCC should be consulted and find other sources of advice.

Step 4 - Establish whether a Site-Specific Flood Risk Assessment (FRA) is needed

A site-specific Flood Risk Assessment is carried out by (or on behalf of) a developer to assess the flood risk to and from a development site (Planning Practice Guidance Flood Risk and Coastal Change). Chapter 7 of the Development and Flood Risk SPD identifies the development situations for which an FRA will need to be submitted alongside the planning application. These include (this list is not exhaustive):

  • development in Flood Zones 2 and 3, including minor development and changes of use;
  • development involving sites of more than 1ha in Flood Zone 1;
  • development in a ‘critical drainage area’ as identified in the Ipswich Surface Water Management Plan; and
  • development in basements and on lowered ground levels.

A planning application may be refused by Ipswich Borough Council if it does not include a Flood Risk Assessment when it is required, or the contents are not satisfactory. The Sequential and Exception Test (if required) can be included as part of the site-specific Flood Risk Assessment.

Chapter 8 of the Development and Flood Risk SPD sets out the expected content of a site-specific Flood Risk Assessment, including a checklist in Appendix 5 of the SPD.

Who Should Carry Out a Flood Risk Assessment?

A site-specific Flood Risk Assessment should be carried out by a technically competent person. Applicants are advised to check the professional qualifications of any consultant they may choose to conduct assessments. Typically, registration with a relevant professional body such as the Charted Institution of Water and Environmental Management helps to show competence.

Step 5 - Incorporate measures within the development proposal to manage and mitigate flood risk

After applying a sequential approach so that, as far as possible, development is located where there is the lowest risk of flooding, new development can be made safe by:

  • designing buildings to avoid flooding by, for example, raising floor levels;
  • providing adequate flood risk management infrastructure which will be maintained for the lifetime of the development;
  • leaving space in developments for flood risk management infrastructure to be maintained and enhanced; and
  • mitigating the potential impacts of flooding through design and flood resilient and resistant construction.

Applicants will need to demonstrate that equality considerations have been applied where appropriate to the design of flood mitigation measures, such as safe refuges within buildings or evacuation plans.

Chapter 9 of the Development and Flood Risk SPD sets out the ‘Safety Framework’ to be applied to development proposals within Ipswich Borough. It addresses:

  • Suitable finished floor levels;
  • Self-contained basement development;
  • Safe access/egress;
  • Safe refuge;
  • Flood Risk Emergency Plans;
  • Structural safety of buildings; and
  • Special measures and information to assist emergency services.

Step 6 - Check whether the Exception Test is needed

The Exception Test (NPPF paragraph 164) is a method to demonstrate that flood risk to people and property will be managed satisfactorily, while allowing necessary development to go ahead in situations where suitable sites at lower risk of flooding are not available.

The requirement to apply the Exception Test is based on the area in which the site is located and the vulnerability classification of the proposed development.

For the Exception Test to be passed it should be demonstrated that:

a) the development would provide wider sustainability benefits to the community that outweigh the flood risk; and

b) the development will be safe for its lifetime taking account of the vulnerability of its users, without increasing flood risk elsewhere, and, where possible, will reduce flood risk overall.

Chapter 10 of the Development and Flood Risk SPD advises applicants how to complete the Exception Test.

This page provides a user guide to the Ipswich Borough Council Development and Flood Risk Supplementary Planning Document, 2022.  National Guidance is also available through the Flood Risk and Coastal Change Planning Practice Guidance.