Debate on flooding and planning and developer responsibilities

A debate has been scheduled in Westminster Hall for Tuesday 14 May at 4.30pm on flooding, planning and developer responsibilities. The debate has been sponsored by George Freeman MP.

Flooding and planning are devolved areas, and the below information relates to England.

Background

Several million properties in England are at risk of flooding. In 2022-23, the Environment Agency estimated that approximately 5.7 million properties in England were at risk from flooding, an increase of around 500,000 from the previous year.

There are different sources of flood risk; for example, from rainwater, rivers, the seas and coast. It is not possible to prevent all types of flooding or coastal erosion, but the impacts on communities can be reduced with effective planning and management.

General responsibility for managing flooding

An overview of flooding responsibilities is set out in the Library research briefing Flood risk management and funding. Powers relating to flooding are permissive, and home owners are responsible for protecting their own property and land. However, there are responsibilities for various different 'risk management authorities' to manage the risks of flooding.

The Department for Environment, Food and Rural Affairs (Defra) leads on flood risk management and provides funding for projects.

The Environment Agency (EA) disburses funding from Defra and delivers flood risk management projects. It produces a national flood and coastal erosion risk management (FCERM) strategy for England. The current strategy was published in July 2020, alongside a new government policy statement on FCERM. The EA’s strategy was updated in June 2022 with the publication of a roadmap to 2026. The current national strategy focuses on resilience, and includes measures to:

• create ‘climate resilient places’ (through understanding the impacts of climate change on flood risk),
• invest in infrastructure and make planning decisions with a long-term focus, and
• ensure local communities understand their own flood and coastal risk responsibilities, and how to act.

The EA is also responsible for managing the flood risk from main rivers and the sea, and maintains national flood defences.

Lead local flood authorities (LLFAs) are the local authority responsible for local government functions (for example, a unitary authority or county council). LLFAs are responsible for developing and applying a local flood risk management strategy. They have lead responsibility for managing the risk of flooding from surface water, groundwater and ordinary watercourses in their area, such as supporting or funding local flood defences. In some particularly low-lying areas, the role of LLFAs is undertaken by Internal Drainage Boards (IDBs, independent public bodies covering around 10% of England, which have some powers to carry out works to manage localised risk of flooding).

Other groups have specific remits. For example, water and sewerage companies are responsible for minimising the risk of flooding from their networks and ensuring that the areas they serve remain 'effectually drained', while highways authorities are responsible for ensuring that there is sufficient drainage surrounding roads to keep these safe.

Developers have some responsibilities to prevent the risk of flooding to new developments, mainly in relation to ensuring that new sites are not at a high risk of flooding, or that certain mitigations have been put in place to prevent flooding. For example, developers are required to complete a site-specific flood risk assessment alongside planning applications for proposed developments within flood zones 2 and 3 (see below).

Planning and flood risk

The government’s planning policies for England are set out in the National Planning Policy Framework (NPPF) (December 2024). It provides the framework against which local planning authorities (LPAs) draw up their local plans, and which they must consider when deciding planning applications for development. The NPPF is supported by planning practice guidance on flood risk and coastal change (updated 2022).

The NPPF sets out that new development should consider flood risk, and take steps to manage this:

"Inappropriate development in areas at risk of flooding should be avoided by directing development away from areas at highest risk (whether existing or future). Where development is necessary in such areas, the development should be made safe for its lifetime without increasing flood risk elsewhere."

It sets out Local Planning Authorities (LPAs) should apply both sequential and exception tests when they allocate sites that may be at risk of flooding for development within their local plans or decide planning applications for new development. For planning applications the NPPF says:

“A sequential risk-based approach should also be taken to individual applications in areas known to be at risk now or in future from any form of flooding”

Government guidance on ‘Flood risk assessment flood zones 1, 2, 3 and 3b’ (April 2025) includes details of sequential and exception tests. It also sets out how to carry out a flood risk assessment in order to complete a planning application.

Sequential and exception tests set that development should take place in the areas with the lowest flood risk (and should not be permitted where there are other similar sites with lower flood risk), and where this is not possible that the new development should provide wider sustainability benefits and be 'safe' for its lifetime. Further information is set out in section 2.3 of the Library briefing Flood risk management and funding.

The EA produces a flood risk map for planning, which sets out the different 'flood zones' across England to assess flood risk. These zones are defined in government guidance as follows:

• Zone 1: Low probability, land with a less than 1 in 1,000 annual probability of river or sea flooding.
• Zone 2: Medium probability, land that has between a 1 in 100 and 1 in 1,000 annual probability of river flooding; or land has between a 1 in 200 and 1 in 1,000 annual probability of sea flooding.
• Zone 3 (a): High probability of flooding, land with at least a 1 in 100 annual probability of river flooding or at least a 1 in 200 annual probability of sea flooding.
• Zone 3 (b): A functional floodplain, that is, “land where water from rivers or the sea has to flow or be stored in times of flood”.

Development is permitted on all four flood zones, if the relevant sequential and exception tests have been passed.

Further information is set out in the Library research briefing Planning and flood risk.