Portland Underhill to Wyke Regis Flood and Coastal Risk Management (FCRM) Project

Share on Facebook Share on Twitter Share on Linkedin Email this link

Background

Chesil beach is an iconic natural barrier beach on the Jurassic Coast of Dorset, extending from West Bay in the west to the Isle of Portland in the east. The beach and Fleet lagoon behind are extensively designated and form an important and essential natural flood defence for the main A354 causeway road to Portland, including approx. 17,000 households that were cut-off by flooding of this road in 2014 (see Figure 1).

The natural beach gradually merges into manmade flood defences and seawalls at Chiswell, Portland, and has seen regular episodes of wave overtopping in the past. The flood defences are owned and managed by a mixture of the Environment Agency, Dorset Council, and private landowners, whilst the main roads and service infrastructure at risk are operated by a variety of service providers.

The beach and frontage are managed via a Beach Management Plan (BMP), whilst the whole area sits within the South Devon & Dorset Shoreline Management Plan (SMP) adopted in 2011. There are over 170 residential and commercial properties at direct risk of coastal flooding, erosion, and land instability, as well as significant infrastructure such as the main A354 road and utilities services for Portland. There are many thousands more properties and businesses at indirect risk of coastal flooding, erosion and land instability, particularly in relation to the risk to the A354 being cut-off either temporarily (flood events) or permanently (lost to erosion or land instability issues).

Figure 1: The managed section of Chesil beach from Chesil Cove to the visitor centre, with wave overtopping in February 2014.




The Problem

There are currently a number of increasing pressures on coastal management in this area, which are expected to worsen with climate change and sea level rise. These include:

  • Aging assets and infrastructure will also increase the pressure on maintaining the access to the A354 main road, as flooding and erosion events become more frequent and of greater severity over time. The potential loss of important utilities services to Chiswell, Portland Port or the wider Isle of Portland could have wide-reaching and severe impacts on the local businesses and communities.

  • Chesil beach is naturally migrating back into the Fleet / Portland Harbour due to overtopping events and front face erosion. At Chiswell the beach is constrained and held by hard defences constructed in phases 1958, allowing limited space for further migration at this eastern end of Chesil beach. However, along the A354 the beach may eventually rollback onto the highway or suffer a catastrophic breach.

  • Land instability around Chesil Cove and the West Weares may be worsened if the slope stabilisation measures are allowed to fail and reactivate the landslide complex – posing additional risk to both properties and the A354 as it climbs to provide the only main access route to the top of the Isle of Portland; whilst there will be increasing environmental pressures such as habitat loss and impacts on protected species.

  • There is also the risk posed by sea level rise and climate change to the A354 causeway road from both the Lyme Bay and Portland Harbour sides. This needs to be managed in an integrated way, alongside management of the flood risk at Chiswell. There is a need to investigate this issue further to consider how long-term transport links to Portland can be sustained given the future pressures on the current alignment.

  • The current flood warning and forecasting for the area is provided by the Environment Agency, however the impacts of climate change on coastal processes and water levels will become increasingly harder to predict.


The Purpose of this FCRM Strategy

Dorset Council, working in collaboration with the Environment Agency and with support from BCP Council, Dorset Coast Forum and technical consultants AECOM, are undertaking a project to develop a new FCRM Strategy for the area shown in Figure 2.

Figure 2: Portland Underhill to Wyke Regis FCRM Strategy project extent and key locations.

Once completed, the new FCRM Strategy will define the long-term (100 year) sustainable, adaptable and integrated approach for implementing the SMP2 policy intent for coastal flood and erosion risks, taking into account the latest data and evidence.


Project Approach

The project to develop the new FCRM Strategy will take about 2.5 to 3 years to complete. It will be undertaken in eight stages, summarised as follows:


How you can help

During the project, we will be undertaking six rounds of engagement as follows:

  • During Stage 1, engagement events will be held to raise awareness and seek data to inform the project.

  • During Stage 3, engagement events will be held to present the baseline findings and seek any additional information that may influence these.

  • At the start of Stage 4, option identification workshops with invited representatives will be held to discuss all the possible long list options and appraisal criteria to be used to assess them.

  • During Stage 5, engagement events will be held to present the long-list option appraisal and draft short list.

  • During Stage 7, engagement events will be held to present the draft findings of the detailed short list option appraisal and draft leading options. This will be a 3-month Statutory Consultation.

  • During Stage 8, engagement events will be held to raise awareness of the final approved Strategy and explain what happens next.

For Stage 1 Engagement - a survey seeking information from the community to help inform the project closed on 12th November 2023. This information is now being analysed to share with the project team and then the wider community.

Background

Chesil beach is an iconic natural barrier beach on the Jurassic Coast of Dorset, extending from West Bay in the west to the Isle of Portland in the east. The beach and Fleet lagoon behind are extensively designated and form an important and essential natural flood defence for the main A354 causeway road to Portland, including approx. 17,000 households that were cut-off by flooding of this road in 2014 (see Figure 1).

The natural beach gradually merges into manmade flood defences and seawalls at Chiswell, Portland, and has seen regular episodes of wave overtopping in the past. The flood defences are owned and managed by a mixture of the Environment Agency, Dorset Council, and private landowners, whilst the main roads and service infrastructure at risk are operated by a variety of service providers.

The beach and frontage are managed via a Beach Management Plan (BMP), whilst the whole area sits within the South Devon & Dorset Shoreline Management Plan (SMP) adopted in 2011. There are over 170 residential and commercial properties at direct risk of coastal flooding, erosion, and land instability, as well as significant infrastructure such as the main A354 road and utilities services for Portland. There are many thousands more properties and businesses at indirect risk of coastal flooding, erosion and land instability, particularly in relation to the risk to the A354 being cut-off either temporarily (flood events) or permanently (lost to erosion or land instability issues).

Figure 1: The managed section of Chesil beach from Chesil Cove to the visitor centre, with wave overtopping in February 2014.




The Problem

There are currently a number of increasing pressures on coastal management in this area, which are expected to worsen with climate change and sea level rise. These include:

  • Aging assets and infrastructure will also increase the pressure on maintaining the access to the A354 main road, as flooding and erosion events become more frequent and of greater severity over time. The potential loss of important utilities services to Chiswell, Portland Port or the wider Isle of Portland could have wide-reaching and severe impacts on the local businesses and communities.

  • Chesil beach is naturally migrating back into the Fleet / Portland Harbour due to overtopping events and front face erosion. At Chiswell the beach is constrained and held by hard defences constructed in phases 1958, allowing limited space for further migration at this eastern end of Chesil beach. However, along the A354 the beach may eventually rollback onto the highway or suffer a catastrophic breach.

  • Land instability around Chesil Cove and the West Weares may be worsened if the slope stabilisation measures are allowed to fail and reactivate the landslide complex – posing additional risk to both properties and the A354 as it climbs to provide the only main access route to the top of the Isle of Portland; whilst there will be increasing environmental pressures such as habitat loss and impacts on protected species.

  • There is also the risk posed by sea level rise and climate change to the A354 causeway road from both the Lyme Bay and Portland Harbour sides. This needs to be managed in an integrated way, alongside management of the flood risk at Chiswell. There is a need to investigate this issue further to consider how long-term transport links to Portland can be sustained given the future pressures on the current alignment.

  • The current flood warning and forecasting for the area is provided by the Environment Agency, however the impacts of climate change on coastal processes and water levels will become increasingly harder to predict.


The Purpose of this FCRM Strategy

Dorset Council, working in collaboration with the Environment Agency and with support from BCP Council, Dorset Coast Forum and technical consultants AECOM, are undertaking a project to develop a new FCRM Strategy for the area shown in Figure 2.

Figure 2: Portland Underhill to Wyke Regis FCRM Strategy project extent and key locations.

Once completed, the new FCRM Strategy will define the long-term (100 year) sustainable, adaptable and integrated approach for implementing the SMP2 policy intent for coastal flood and erosion risks, taking into account the latest data and evidence.


Project Approach

The project to develop the new FCRM Strategy will take about 2.5 to 3 years to complete. It will be undertaken in eight stages, summarised as follows:


How you can help

During the project, we will be undertaking six rounds of engagement as follows:

  • During Stage 1, engagement events will be held to raise awareness and seek data to inform the project.

  • During Stage 3, engagement events will be held to present the baseline findings and seek any additional information that may influence these.

  • At the start of Stage 4, option identification workshops with invited representatives will be held to discuss all the possible long list options and appraisal criteria to be used to assess them.

  • During Stage 5, engagement events will be held to present the long-list option appraisal and draft short list.

  • During Stage 7, engagement events will be held to present the draft findings of the detailed short list option appraisal and draft leading options. This will be a 3-month Statutory Consultation.

  • During Stage 8, engagement events will be held to raise awareness of the final approved Strategy and explain what happens next.

For Stage 1 Engagement - a survey seeking information from the community to help inform the project closed on 12th November 2023. This information is now being analysed to share with the project team and then the wider community.

  • CLOSED: This survey has concluded.

    Engagement Round 1

    The Portland Underhill to Wyke Regis FCRM Strategy will identify where, when, and broadly what type of works are needed to protect this coastline from flooding and erosion. 

    We are at the start of this journey, but throughout the strategy development there will be several opportunities for you to share your comments and opinions with Dorset Coast Forum to help inform and develop this strategy. 

    Please get involved by completing this survey.

    This survey will close on Sunday 12th November at 10pm.

    Thank you

    Take Survey
    Share on Facebook Share on Twitter Share on Linkedin Email this link
Page last updated: 05 Dec 2023, 03:59 PM