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Long Term Flood Risk In England

This is a complete guide to long term flood risk in England.

It has information on areas prone to surface water flooding, sea and river flooding, and reservoir flooding.

You will find guidelines regarding finding information on long term flood risk in your area.

If you’re planning to invest in a development site or build a property, this article will have holistic information regarding long term flood risks in England.

The Basic Concepts

In this chapter, I’ll answer the question: “What are long term flood risks, and how to find information on long term flood risk in England?”

Long-term flood risk entails measuring the likelihood of flooding occurring over a certain period and the impacts of such flooding on the people, environment, and economy.

Let’s get started

Finding information on Long Term flood risk

Before starting a project or construction in any area, it is better to understand risks to local flooding. You have multiple sources of information online to learn about flood risk in any location in England. We recommend using credible sources to find information

Below is an instruction on how to find flood risk level in your area.

First, go to the UK government website by clicking thelink here. 

In the drop-down tab under flood risk, you have multiple options. Select one that is relevant to you.  In the right hand tab, enter a postcode to see flood risks in that area.

Screenshot 2023 01 16 at 10.14.03

You can also find information on long-term flood risk by using our flood risk map UK map and follow the below instructions. 

Screenshot 2023 01 16 at 10.21.20.png

Once you select flood risk maps, you can enter your post-code to see flood risk in your area.

long term flood risk in england

Finding information on types of long term flood risk

The section guides you about finding information on different types of long-term flood risks. 

Long term flood risk can emerge from surface water, flesh floods, sea or river, and reservoirs. Your area might be prone to one or more sources of flooding. 

You need to check the following sources of flooding: 

1. Surface Water Flooding

2. River and Sea Flooding

3. Reservoirs 

Let’s get started

River and Sea Flooding

River floods happen when the drainage from the surrounding overpowers the channel, and it can no longer contain the flow. It can also occur when the water quantity exceeds the channels’ average carrying capacity. 

Coastal flooding occurs when high tights and stormy conditions collide. In coastal flooding, sea water floods low-lying land, which is often dry.

You can check maps of properties at risk of flooding in the England from the river and sea flooding following the same procedure mentioned above and just by choosing the right option.

By entering your postcode in the right-hand tap, you will be able to see your property’s flood risk.

Follow the instructions below

long term flood risk

You can see examples of  flood resilient interventions at the city level. This shows that water can be managed and livelihoods can be protected. 

Surface water flooding

Surface water and small watercourse flooding occur due to heavy rains, and the rainwater doesn’t drain out through the standard drainage system. 

Flooding happens because the water level is too high to be drained out in time or the drainage system is inadequate to handle such pressure. In addition, when the underground drainage system cannot drain rainwater level on time, the water table rises above the ground, and in such cases, groundwater flooding occurs.

You can look at the options to control surface water flooding.  

You can check maps of properties at risk of flooding in England from surface water flooding following the same procedure mentioned above and just by choosing the right option. Follow the instructions below.

Screenshot 2023 01 16 at 11.02.43.png


Reservoirs are artificial lakes created by building dams across rivers. Structural faults of the dams or water overflow can result in reservoir flooding affecting the surrounding areas.

Follow the instructions to check flooding maps of flood risks from reservoir. You can assess the risk of surface water flooding 

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Overview of long term flood risk in England

Long-term flood risks emerge from various sources of floods, i.e., surface water, river and sea, and reservoirs.
In this section, you will find information on the following things.

An overview of long-term flood risk in England.
Data from the reports of The Environment Agency of UK.

Long-term flood risk maps

Map of current flood risk warrants by the government.

Long- term flood risk in England – Overview

The 2008 National Flood Risk Assessment Reports from The Environmental Agency concluded that 2.4 million properties are at risk of flooding from sea and rivers in England.

The report further suggested that in England, 2.8 million properties are prone to Surface water flooding alone. In total, 5.2 million properties in England are at risk of flooding, which puts one in six properties at risk.

The figure below shows England’s long-term flood risk from rivers and the sea.

Screenshot 2023 01 16 at 11.22.20.png

The picture below shows the areas more prone to floods in the England.

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The Environment Agency also provides maps and information on Flood warnings. The flood risk shown by The Environment Agency is shown in the picture below. The warning signs are placed at high flood risk areas.

Screenshot 2023 01 16 at 11.31.02.png

Assessing long-term flood risk

Two leading flood assessment tools for development applications are

Flood Risk Assessments (FRAs)

Sequential and Exception testing.

There might be an interaction in using these two flood assessment tools. However, not all development applications require the use of both assessment tools.

In this section we will cover short description about both tools. 

Flood Risk Assessments (FRAs) and the Sequential/ Exception testing

Site-specific Flood Risk Assessments are carried out for development projects within Flood Zones 2 or 3.

The assessment is also required for development located in flood zone 1 but covers more than one-hectare area.

A Flood Risk Assessment (FRA) first identifies if the property is susceptible to floods. It will allow the developers to ensure the site’s safety, and the development will not create flood risks anywhere.

In some cases, a sequential test is required to demonstrate that the development is required within the flood zone.

The purpose of sequential assessments is to direct new developments in areas with the lowest flood risk. Sequential tests are required for areas where flood risks prevail in the current time or future.

Some developments are allowed in flood-risk areas only in exceptional circumstances. In such a situation, the exception test is used when the sequential test has already been passed.

The National Planning Policy Framework advises local authorities to use the Sequential Test to allocate development to sites with low flood risks.

Factors that contribute to long-term flood risk in England

Several environmental factors and human factors cause long-term flooding.

In this section, you will learn about three main factors contributing to long term flood risk in England.

Climate change and sea level rise
Land use changes
Infrastructure development

Flooding, as mentioned above, has many forms. For example, it could be heavy rains, coastal storms, or artificial structures, i.e., dams, that cause flooding. In addition, climate change is making drastic changes around the world. 

For example, according to the red crescent in 2020, England received 141% of its average rainfall in February in just two weeks. According to Environment Agency, the leading causes of floods in the UK are climate change, green space reduction, and population increase. 

As a result, extreme events are four times more likely than in the 1970s. Since 1910 UK has experienced 17 record-break rain months, and nine of those months were since the year 2000.

Climate change and sea level rise

According to the Climate Change: Global Sea Level research studies, since 1880, the global sea level has risen about 12 – 14 centimeters. 

The rise in sea level is caused by a combination of factors, i.e., the increase in glacier melting and the thermal expansion of seawater. Global means the water level in the ocean has increased by 3.6 millimeters per year between 2006 to 2015.

Screenshot 2023 01 16 at 11.59.01.png

Picture Source: Research Study -Climate Change

Land use changes

Screenshot 2023 01 16 at 12.03.41.png

The agriculture sector in the UK dominates land use. About 75% (24 million ha) land of the total area of the UK was used for agricultural purposes.

Most of the site is grassland, around 60% used for rough grazing, and the rest for bare fallow and corps. The total area of agricultural land decreased to less than 17 million ha in 2005 from 19.8 million in 1961.

Land use change has solid consequences for floods. Human society has changed natural habitats drastically over time. Large parts of the land are drained or deforested, which impacts soil erosion. Deforestation in the mountains and hilly area leave lowlands prone to flash floods.

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Infrastructure development

Human infrastructure development has tampered with many natural habitats.

Many agricultural land and forests have been converted into infrastructure sites. Such changes in land use as mentioned above increase the risk of flooding.

Flood risks are unavoidable in foreseeable future, therefore new infrastructure development needs to take flood risk assessment seriously.

Before planning a development, relevant authorities and flood assessment agencies need to be consulted for proper information. 

Understanding and managing flood risk is essential for safe infrastructural development

Impacts of long-term flood risk in England

The section the impacts of long term floods in England which includes 

  • Environmental Impacts  
  • Economic Impacts 
  • Social Impacts 

Climate change has already been showing its devasting impacts in UK.

One of the major incidents that happened in recent years is Strom Desmond in 2015.

Met office forecasts have predicted that flesh floods resulting from rainfalls would be five times more by the end of the century.

A recent CCRA report shows that around 1.8 million people are living in areas that are prone to flood risks occurring from surface, river or coastal flooding.

Screenshot 2023 01 16 at 12.15.37.png

Picture Source : Flooding in England: A National Assessment of Flood Risk

Environmental Impacts

Flooding has tremendous consequences for the environment besides human lives.

Floods interpret the natural ecosystem, and many small mammals and insects are at risk of losing their natural habitats.

The freshwater ecosystem is particularly in danger because of the long-term flood risks.

According to British Ecological Society  “the most profound effects of climate change on freshwater ecosystems”

Social Impacts

The social consequence emerging from floods are numerous. Mostly the economically underprivileged segments of society suffer the consequences.

In UK 61% of low-income renters do have home contents insurance, which makes them the most financially susceptible segment of society.

Flooding has tremendous impacts on the mental health of individuals.

According to research from the department of environment, food and rural affairs people who experience damage due to floods, and storms have 50% more chances of experiencing stress and depression.

Economic Impacts

Flooding has tremendous consequences for the environment besides human lives.

Floods interpret the natural ecosystem, and many small mammals and insects are at risk of losing their natural habitats.

The freshwater ecosystem is particularly in danger because of the long-term flood risks. According to British Ecological Society  “the most profound effects of climate change on freshwater ecosystems”


Now I want to turn it over to you: What do you think is the part that is more helpful?

Do you have sufficient info to evaluate long term flood risk?

Table of Contents


Argemiro Rivera, <b>BEng(Hons) MSC CEng MICE MCIWEM C.WEM CEnv</b>
Argemiro Rivera, BEng(Hons) MSC CEng MICE MCIWEM C.WEM CEnv

Passion for Water, Flood Risk & Sustainability
I love to dig into complex flood risk and water engineering projects and deliver them. I focus on delivering reliable flood risk information to protect livelihoods and the environment.

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