Building in a flood plain

Guidance for local planning authorities and decision takers (for example local communities, elected members, statutory consultees for planning issues) both in drawing up the Local Plan for development areas and making decisions about planning applications is given in the National Planning Policy Framework (pdf, 870 KB) and the guidance for Flood risk and coastal change (external website).

Developers planning to build in a flood plain should be familiar with the framework and accompanying guidance.

Role of the Suffolk Resilience Forum in relation to developments in flood plains

In Suffolk, the emergency services and local authority have agreed to look collectively at the proposed evacuation plan when the planning application is submitted, they will not give advice on the preparation of the Flood Risk Assessment or in the preparation of the evacuation plan.

The Suffolk Resilience Forum (SRF) will only look at documentation produced to meet the planning requirements where a development is subjected to the Exception Test (see SRF Exception test process). This is determined using the Environment Agency (EA) flood maps or by the Strategic Flood Risk Assessment for the area and by considering the intended use against the recommendations given in Table 3 (below) which is found in the guidance for Flood risk and coastal change (external website).

Table 3: Flood risk vulnerability and flood zone 'compatibility'

Flood risk vulnerability classification (see table 2)   Essential infrastructure Water compatible Highly vulnerable More Vulnerable Less Vulnerable  
Flood zone (see table 1) Zone 1 Y Y Y Y Y  
Zone 2 Y Y Exception test required Y Y  
Zone 3a Exception test required Y N Exception test required Y  
Zone 3b functional flood plain Exception test required Y N N N  

Key: Y - Development is appropriate. N - Development should not be permitted.

As part of the documentation there is a requirement to produce a Flood Emergency Plan (FEP), guidance on what should be found in the plan can be found in the example.

In order to be able to comment on the Flood Emergency Plan, the SRF will also need the Flood Risk Assessment documentation produced by the developer.


These are taken from the National Planning Policy Framework:

  1. Evacuation for foreseeable flooding risks - includes safe access and raised egress routes for voluntary and free movement of people
  2. Evacuation - where Flood Warnings have been issued by the EA for more severe flood events, provides safe evacuation routes to allow timely unaided evacuation of people
  3. Evacuation - provides an evacuation plan for use by the owners of buildings with transient occupants
  4. Evacuation - allows for the continued viability of access and evacuation routes for the lifetime of the development
  5. Shelter on site - provides safe refuges for no-notice flood events
  6. Shelter on site - provides safe access routes for emergency services to safe refuge locations to allow rescue of people who are unable to evacuate themselves.
  7. Signage - provides clear signage to highlight risk of flooding, and evacuation routes
  8. Good design – demonstrating compliance with ’Improving the flood performance of new buildings: flood resilient construction’ (download:  improving the flood performance of new buildings: flood resilient construction) (external website)
  9. Critical infrastructure – includes appropriate access to critical infrastructure (eg fire hydrants) likely to be required by local responders in an emergency situation.

The Suffolk Resilience Forum will not advise developers on measures to take for individual sites.

The purpose of this guidance is to highlight the areas that need to be considered when developing a Flood Evacuation Plan (FEP), including flood warnings, safe routes and evacuation options. The list is not necessarily a comprehensive list of areas to be included in the plan as developments vary enormously, plans should be tailored to the individual developments.

Flood evacuation plan contents:

  • Name and address of premises
  • Purpose and scope of plan
  • Location - description and map
  • Description of proposed development - residential, commercial, tourism
  • Main source of flooding identified / Local indicators of potential flooding
  • How occupants are made aware of flood evacuation plan - distribution list, solicitors, part of deeds
  • EA Floodline Warnings Direct information in plan
  • How will flood warnings be received and by whom? (text, phone, fax, e-mail)
  • How will visitors or occupants be notified that the site is closed? Procedures - actions to be taken on receiving flood warnings, isolating utilities, relocation of vehicles / stock (if appropriate)
  • Flood Alert Notices - locations
  • Occupants - particularly vulnerable or not, if vulnerable special mechanisms in place for alerting / evacuation etc
  • Evacuation routes - primary and alternative
  • On-site refuge
  • Flood Kit advice
  • Re-occupation
  • Contact lists
  • Advice on dangers of flood water

National Planning Policy Framework (external website)

 

Department for Communities and Local Government - Guidance - Flood risk and coastal change (external website)

 

Suffolk County Council - Guidance on  developments and flood risks (external website).

 

Environment Agency - Flood risk assessment: local planning authorities (external website).

 

Developments in areas susceptible to flooding in Ipswich - additional information is available the Ipswich Borough Council - Development and Flood Risk Supplementary Planning Document (SPD)