Managing the risk of flooding

Your development must be safe from flooding and must not increase the risk of flooding elsewhere. Making space for water can provide valuable green space, adding value to your development.

Summary

Contact us as early as possible to find if your site is at risk from flooding. If it is, we can tell you whether development is likely to be acceptable, and then the steps you can take to manage the risk.

Our job is to help you avoid or manage the risk of flooding. We work with other organisations and take action to avoid or reduce the likelihood and consequences of flooding.

Our advice

Managing flood risk is a major issue for any development. We want you to consider some big questions at this stage to help you understand it. The location, layout and design of developments - in that order - are the most vital factors determining both the likelihood and consequences of flooding.

Built developments should be located in areas of lowest risk. This is in accordance with the Government's new Planning Policy Statement 25 (PPS25): Development and flood risk. You need to ensure the site land use and layout is appropriate to this risk. Housing and access roads are vulnerable to flooding, whereas open space and informal recreational areas are generally compatible and can help manage flood risk by making space for water.

Your development must:

be safe from flooding and
must not increase the risk of flooding elsewhere.

Together with the local authority, we will want to see you demonstrate in your flood risk assessment that you have considered all forms of flooding, its consequences and reduced the overall flood risk for the lifetime of the development.

Getting the go-ahead

We will object to developments that are likely to be at high risk of flooding or increase the risk to others.

We can also refuse to give our own consent to works that we consider to be harmful to the environment, even if the scheme is sound from an engineering point of view. For example, we are generally opposed to culverting watercourses and to works on tidal rivers that encroach riverward of the flood defences. Our policy is to actively restore culverted channels to natural water courses.

We want you to design schemes that avoid flood risk or reduce the likelihood and consequence of flooding and also enhance the environment. Setting back riverside defences and designing green, floodable storage spaces and routes for water can create a safe, attractive and well-connected development for both people and wildlife.

Extreme floods will happen

It will never be possible to eliminate flood risk altogether. Even if the local planning authority accepts the flood risks associated with your development, you must:

include methods of reducing the risk, and
have appropriate flood resilience or resistance measures.

Emergency planning

A safe development will require good emergency planning procedures to be in place. This should be part of the flood risk assessment. Planning, building and maintaining development in flood risk areas will cost more, and is your responsibility.