Climate adaptation

What are the climate hazards Colchester will face, and how will they impact us?

There are several different climate hazards that we will face including heatwaves/extreme heat, flooding, drought, storms and more. The impacts of each are outlined below:

Heatwaves/Extreme heat

There is an increasing chance of extreme heat events impacting Colchester in the future, with recent summers in 2018 and 2022 showing this with temperatures nearing 40°C and longer periods of time with temperatures above 27°C. The impacts are widespread and include:

• Increased incidence of wildfires
• Impact on people’s physical health and wellbeing, with increased deaths as a result of heat stress
• Disruption to transport from railway lines buckling under high temperatures
• Increased chance of drought conditions, impacting ability to grow crops and provide clean drinking water

Extreme cold periods will likely continue to occur, but these are likely to become less frequent as winters become warmer. This is positive for helping people to keep their homes warmer using less energy. However, it is still important to save energy through reducing energy use and making your property retain heat through measures like insulation and draughtproofing. 

Flooding

Despite Colchester’s climate being drier than most areas of the UK, there is still some areas that are vulnerable to flooding. Flooding can result directly from heavy rainfall, from rivers bursting their banks and overflowing or from the sea flooding the land because of sea level rise and storm surges. Areas such as Mersea Island are predicted to be particularly affected by sea level rise and coastal flooding, whereas other locations may be impacted by being in the vicinity of rivers such as the Colne. The impacts that may be seen include:

• Damage to property
• Impact on mental wellbeing as a result of property damage, loss of belongings or the death of relatives and friends
• Disruption to travel from roads or paths being flooded and becoming impassable
• Impact on water quality from pollutants and chemicals being more easily washed off farms and highways as well as untreated sewage released into rivers during heavy rainfall.
• Erosion of land and soils. Coastal flooding combined with sea level rise is damaging areas of the coastline near Colchester which can in turn impact on homes, farmland, habitats and more.
• Subsidence of land. Much of the soils in Colchester are clay based, which can absorb and hold water. When the soils do this they expand in volume. However, when dry, warm periods occur the soil becomes cracked and hard leading it to reduce in volume. This causes the soil to ‘shrink’ meaning the land becomes unstable and can cause damage to property foundations and lead to trees falling.

Drought

Essex is classed as a ‘severely water stressed area’ and only 60% of drinking water consumed in Essex comes from within the county. There is a need for water usage in homes to reduce in Colchester and wider Essex, with 155-160 litres per person per day the current usage, compared to 144 litres per person per day for the UK. It is increasingly likely that restrictions on water usage could occur as the climate in Colchester, particularly in summers, becomes drier. The impacts of drought can include:

• Damage to crops due to lack of water impacting growing conditions
• Reduction in water quality and availability leading to imposed action to reduce water usage such as imposing hosepipe bans
• Harm to wildlife due to rivers drying out and loss of habitat.  

Storms

It is harder to predict the future frequency and impact of storm events. However, storms are becoming more frequent, with 10 storms hitting the UK between September 2023 and January 2024, noticeably more than previous years. The impact of storms can be wide ranging, as strong winds often combine with heavy rain as well as contributing to coastal flooding as seawater is blown on land. The impacts of storms can be widespread but typically cause:

• Disruption to travel from high winds making travel dangerous or fallen trees or other infrastructure making roads impassable
• Damage to building or homes from fallen trees or other infrastructure
• Powercuts from damage to powerlines. These tend to be short, temporary issues but can be up to several days.

There is the potential for these climate hazards to combine with each other, leading to the risks of each being worsened. Each of these hazards can also lead to a sequence of risks occurring. For example, a flood event occurring could lead to a road becoming impassable, which in turn could prevent people from getting to work and operating a key job or service. Understanding these interacting hazards and risks, alongside their impacts on different organisations is complex but it is something we will consider in any adaptation planning work we might do.