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Flood Risk Assessment: A guide to what you need to know when making an application for planning permission

By September 24, 2015Flood Protection News

Putting in a planning application means gathering a number of pieces of information and evidence regarding the work you want to carry out. This can be the architectural drawings of the desired building, the location of the work and perhaps documentation regarding provision of utilities such as drainage or the placing of a septic tank.

There is a further piece of preparatory work you may need to carry out, dependent on your location and the planned works and this is a flood risk assessment.

What is a flood risk assessment?

A flood risk assessment looks to ensure that developers have knowledge of the recommendations of the Environment Agency with regards to previous or predicted flooding.

It is designed to put safeguarding measures in place which mean a development will be safe from flooding as much as is possible, that the finished project is sustainable in regard of the detailed risks and has flood protection elements in place where needed.

A flood risk assessment covers both new and existing developments. It is relevant to both large scale developments through to small amounts of work to be carried out by individual home or business owners. The result of the assessment means that a flood resilient design can be put in place at the earliest possible stages.

If one is requested and not provided, or is not of satisfactory quality, planning permission may be refused.

When an assessment will be required

With regards to flood protection, many parts of the UK are classed as being in a certain flood zone. Classed from zone 1 to zone 3, those in a zone 1 are at the greatest risk of flooding. The Environment Agency and local authority can let you know if where you are looking to gain planning permission for falls into any of the zones.

A flood risk assessment is almost always necessary if the development falls within a flood zone. If a development is:

  • In zone 1 and covers over a hectare of land
  • In zone 1, under a hectare and is a change in class of use
  • In zone 1 and the Environment Agency has deemed the drainage systems to have ‘critical’ issues
  • In zone 2 or 3 and is either a change of use or a minor development

Then a flood risk assessment will be necessary.

Look to take advice in certain situations

There is advice prescribed by the Environment Agency in a number of other situations. These cover scenarios regarding minor extensions to buildings, work requested on land which is classed as ‘vulnerable’ or is deemed ‘water compatible’ and is in zone 2. ‘Water compatible’, covers a number of commercial industries such as marinas, sewage transmission, ship building and docks.

How to carry out an assessment

A flood risk assessment should usually be carried out by a trained professional. However, if the planning permission application is for minor works then it is sometimes acceptable to carry out and submit your own assessment report.

The risk assessment checklist is extensive and includes:

  • Type of development
  • Flood risk vulnerability classification (i.e zone)
  • On site flood hazards
  • Existing drainage arrangements
  • Probability of flooding using Environment Agency data
  • Demonstrating how development in a flood risk area will been safeguarded and minimised
  • How the risk of flood will be managed when the development is complete

Flooding is a very real part of the lives of many in the UK. If you don’t already know if your property is in a flood zone area and you’re thinking of doing work on it such as an extension, it’s worth finding out before you put in your planning permission application. If you are in a flood zone, carry out the risk assessment as needed and at the same time be prepared for any flooding by putting flood protection measures in place to protect both your home and your possessions.