Do I need a Flood Risk Assessment for a Major Development?

Why is a Flood Risk Assessment Required for Major Developments?

In accordance with the National Planning Policy Framework and Environment Agency guidance on development and Flood Risk any development located in Flood Zone 2 , 3 , a critical drainage area or is located in Flood Zone 1 with an area of greater than 1ha is required to have a Flood Risk Assessment to validate the planning application. This includes Major Application. To find out more about when a Flood Risk Assessment is required and what makes a Flood Risk Assessment… check out our Flood Risk Assessment Page.

What is a Major Development?

For the purposes of assessing flood risk and water management the definition of a Major Development is split between residential and non-residential uses.

A residential Major Development contains either: 10 or more dwellings, or a development on a site of 0.5 hectares of more.

A non-residential Major Development consists of either a development of 1,000 square metres or more, or the development sits on a site of over 1 hectare.

Due to the size of the development, either in number of dwellings proposed or site area, two documents pertaining to water are always required at planning: a Flood Risk Assessment and a Drainage Strategy.

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What Flood Risk Assessment do I need for a Major Application development ?

A Flood Risk Assessment for a Major Development Application needs to assess the environmental constraints of the site against what is being proposed. It further needs to be informed by good data. A Flood Risk Assessment using good data allows for better decision making and can in some cases save time and spend on a project. A Flood Risk Assessment should always be written by a competent Flood Risk Consultant who can best advise how the development could be impacted by flooding and whether it could cause flood risk elsewhere. Essentially is the design or layout of the development policy compliant. A competent Flood Risk Consultant can advise whether design changes or additional mitigation is going to be required to make the development suitable for planning.

Major Development in flood risk zones, could cause flood issues in several ways. Either the development itself could have a high risk of hazards associated with potential flooding (for instance flood damage in residential buildings or being trapped in a building surrounded by flood water), or as a result of the development, flooding could be pushed offsite (displacement), causing a change in the flood risk of neighbouring properties/premises.

Similarly, it is important to check whether the proposed Major Development is being built in an appropriate location for its intended use. This is one of the main requirements of the Exception Test and Sequential Test, which are required when writing a National Planning Policy Framework compliant Flood Risk Assessment.

Major Developments consist of 10+ residential units and non-residential developments being 1000 square metres, the amount of land required to support these developments is great. With greater land coverage there is an increased risk that the land/Site could be susceptible to flooding. It is therefore recommended to engage with a Flood Risk Consultant that understands the National Planning Policy Framework, Planning Practice Guidance and Environment Agency advice on development and flood risk. By working with a competent Flood Risk Consultant, they can use their previous project experience of assessing the flood risk affected areas of the Site, whilst also advising how to make the development more likely to be approved at planning with a Flood Risk Assessment.

How can Aegaea support with your Flood Risk Assessment ?

At Aegaea, all our staff have experience working with developments of all sizes. Our team of experts can work with you through the production of the Flood Risk Assessment on how the development could be best arranged to make it more acceptable to the Sequential Test and Exception Test.

It is important to note that our team do not require the masterplan to be finalised to be able support with your enquiry. If anything we prefer to be involved on a project as early as possible so that we can better advise on the development potential of a site. As a result of our experience we are able to review brownfield and greenfield sites and work with you to advise on what possible constraints could exist with focus to Flood Risk and developing a Site. We find that this can benefit a project early on especially in achieving a successful outcome at Planning.

Our team can advise on what mitigation measures could be required to mitigate flood risk to the proposed development. Whilst, also advising early on in a project whether certain parts of the development would not be acceptable. By providing this level of advise in the Flood Risk Assessment process so early on it can reduce time and spend on the planning application and other services.

Each project is unique and as such a bespoke Flood Risk Assessment is required to be more acceptable at planning. We are here to help you produce a functioning, viable development which is safe for occupation and responsibly acknowledges the risk of flooding onsite. You can visit our Flood Risk Assessment page, to find out more about that they are, or you can contact us to discuss further on how we can help you. Or if you know what you need a require a Quotation… get a quote.

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Aegaea work alongside home owners, private developers, planning consultants, architects, local authorities, international development agencies and contractors. Aegaea know exactly how to help you.

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