Draft Flood Risk Supplementary Planning Document

2.4 Part 4 of FRA: Avoiding flood risk

Although not all developments will need to pass the Sequential and Exceptions Tests, they will still require an FRA to demonstrate how the development can be made safe and that it does not increase flood risk elsewhere as well as taking into account other sources of flooding.

2.4.1 The following section provides additional detail on when the Sequential and Exceptions Tests will be applied and how to meet the requirements. This will assist applicants in completing Part 4 of the FRA proforma.

What is the Sequential Test?

2.4.2 This general approach is designed to ensure that areas at little or no risk of flooding are developed in preference to areas at higher risk. The aim being to keep development out of medium and high risk areas (Flood Zones 2 and 3), and other areas affected by flooding, where possible.

When is the Sequential Test required?

2.4.3 The Sequential Test is required for individual planning applications located in Flood Zones 2 and 3 unless it is included in the list of exemptions shown below.


  • Sites allocated in the Local Plan
  • A sequential test has already been undertaken for development of the type proposed on the site in question
  • Minor development[1]
  • Change of Use applications, unless it is for a change of use of land to a caravan, camping or chalet site, or to a mobile home site or park home site.
  • Development proposals in Flood Zone 1 unless the SFRA, or other more recent information, indicates there may be flooding issues now or in the future (for example, through the impact of climate change).
  • Redevelopment of existing properties (e.g. replacement dwellings), provided they do not increase the number of dwellings in an area of flood risk such as replacing a single dwelling with an apartment block

2.4.4 There are some situations where an existing building is vacant because the use is no longer viable and conversion to an alternative use or inclusion of enabling development is necessary to secure its future, bring the site back into use or enable the continued use of a valuable business. In these cases, a reasonable and practical approach will be taken considering the other benefits of the development and the Council may agree that the Sequential Test need not apply. Full justification and evidence must be provided. This will be applied only in exceptional circumstances and the resulting development must then pass both parts of the Exceptions Test ensuring it is safe and does not increase flood risk elsewhere.

1. Minor development – minor non-residential extensions: industrial/commercial/leisure etc extensions with a footprint of 250 sqm or less; alterations: development that does not increase the size of buildings e.g. alterations to external appearance; householder development: for example; sheds, garages, games rooms etc. within the curtilage of the existing dwelling, in addition to physical extensions to the dwelling itself. This definition excludes any proposed development that would create a separate dwelling within the curtilage of the existing dwelling e.g. subdivision of house into flats [back]

How should the Sequential Test be applied for individual planning applications?

2.4.5 The following provides guidance for undertaking the Sequential Test for planning applications:

  • Identify the geographical area of search over which the test is to be applied; this could be the Borough area, or a specific catchment if this is appropriate and justification is provided (e.g. school catchment area or the need for affordable housing within a specific area).
  • Identify the source of 'reasonably available' alternative sites; usually drawn from evidence base / background documents produced to inform the Local Plan e.g. Land Availability Assessment[2]
  • State the method used for comparing flood risk between sites; for example the Environment Agency Flood Map for Planning, the SFRA mapping, site-specific FRAs if appropriate, other mapping of flood sources.
  • Apply the Sequential Test; systematically consider each of the available sites, indicate whether the flood risk is higher or lower than the application site, state whether the alternative option being considered is allocated in the Local Plan, identify the capacity of each alternative site, and detail any constraints to the delivery of the alternative site(s).
  • Conclude whether there are any reasonably available sites in areas with a lower probability of flooding that would be appropriate to the type of development or land use proposed.
  • Where necessary, apply the Exception Test (see below).

2.4.6 Within each Flood Zone, surface water and other sources of flooding also need to be taken into account.  

2.4.7 A site is considered 'reasonably available' under the following circumstances:

  •  It is of a comparable size and can accommodate the requirements of the proposed development;
  •  Either: owned by the applicant, for sale at a fair market value or is publicly owned and surplus;
  •  It is not safeguarded in the Local Plan for another use. 

2.4.8 A site would not be considered to be available if it fails to meet any of the above requirements or already has planning permission that is likely to be implemented. 

Evidence that the Sequential Test has been applied must be included within an FRA
2. Land Availability Assessment - http://www.elmbridge.gov.uk/planning/policy/evidencebase.htm [back]

What is the Exception Test?

2.4.9 The purpose of the Exception Test is to ensure that new development is only permitted in areas at risk of flooding where flood risk is clearly outweighed by other sustainability factors and where the development will be safe during its lifetime, considering climate change and without increasing risk elsewhere.

For the Exception Test to be passed:

Part 1 - It must be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk, informed by the SFRA where one has been prepared; and

Part 2 - A site-specific FRA must demonstrate that 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.

When is the Exception Test required?

2.4.10 The Exception Test is required for :

  • Essential Infrastructure development in Flood Zones 3a and 3b
  • Highly Vulnerable development in Flood Zone 2
  • More Vulnerable development in Flood Zone 3a

How should the Exception Test be applied?

2.4.11 In terms of addressing Part 1 of the Exceptions Test applicants will be expected to demonstrate the sustainability benefits of their application by assessing it against the Council's Sustainability Appraisal framework (Table 12)[3]  

Table 12: SA framework

Sustainability Appraisal Objectives
 1. To provide sufficient housing to enable people to live in a home suitable to their needs and which they can afford.  
 2. To facilitate the improved health and wellbeing of the whole population.
 3. To conserve and enhance, archaeological, historic and cultural assets and their settings
 4. To reduce the need to travel, encourage sustainable transport options and improve accessibility to all services ad facilities
 5. To make the best use of previously developed land and existing buildings
 6. To support economic growth that is inclusive, innovative and sustainable 
 7. To provide for employment opportunities to meet the needs of the local economy
 8. To reduce greenhouse gas emissions and move to a low carbon economy
 9. To use natural resources prudently
10. To adapt to the changing climate
11. To reduce flood risk
12. To improve the water quality of rivers and groundwater, and maintain an adequate supply of water
13. To reduce land contamination and safeguard soil quality and quantity
14. To ensure air quality continues to improve and noise and light pollution are reduced
15. To protect and enhance landscape character

16. To conserve and enhance biodiversity

2.4.12 The following section shows how Part 2 of the Exception Test can be met through the incorporation of appropriate mitigation measures.

3. These have been reviewed and updated following the adoption of the Core Strategy and Development Management Plan [back]