A new Flood and Coastal Erosion Management (FCERM) Strategy to guide how the frontage from Hengistbury Head to Hurst Spit, encompassing Christchurch Harbour, will be sustainably managed for the next 100 years.
Lead Authority
BCP Council
Project start date
July 2021
Page Last Updated
25 Nov 2025
Christchurch Bay and Harbour FCERM Strategy Area
Climate change is putting significantly more properties, infrastructure and open spaces at risk from coastal flooding and erosion. Calculations have revealed that if we do nothing over the next 100 years, the coastal frontage will suffer around £1 billion in damages which includes erosion risk to approximately 1,600 properties and coastal flood risk to over 2,200 properties (homes and non-residential buildings). The figures are not designed to alarm but to help us evidence and justify doing something to manage the risks.
A new coastal strategy
Bournemouth, Christchurch and Poole Council (BCP) and New Forest District Council (NFDC) have worked together with the Environment Agency (EA) to produce a strategy for Christchurch Bay and Harbour. It identifies where, when and broadly what type of works are needed to manage the risks of coastal flooding and erosion over the next century and roughly what they may cost. It will also consider the effects of predicted climate change on coastal communities, including sea level rise and the increased frequency of storms.
As Coast Protection Authorities, BCP and NFDC do not have a statutory duty to undertake coast protection work, but we use permissive powers to protect the coastline and work with communities to help them adapt to future coastal change. In addition, along with the EA, BCP (as Lead Local Flood Authority – LLFA) has statutory responsibilities for managing flood risk; Hampshire County Council is the LLFA covering the NFDC area.
Strategy area
The strategy area stretches immediately east of Hengistbury Head Long Groyne to the western end of Hurst Spit and encompasses Christchurch Harbour up to Tuckton Bridge on the River Stour and Knapp Mill on the River Avon.
We have divided the coastal frontage into six Strategic Management Zones (SMZs), as shown on the Strategy area map above. These help us to identify how we could manage the coastal flooding and erosion risks in each of the linked areas. The SMZs are further divided into 18 Option Development Units (ODUs). These allow us to carry out an options appraisal process to consider how the local requirements of each area could be addressed.
We are also working collaboratively with the Hurst Spit to Lymington Strategy, which borders our strategy area to the east. The two strategies are linked by Hurst Spit, an important coastal feature and landmark of the area. By working together, Hurst Spit can be fully integrated into both strategies:
Funding
Producing the Strategy – In Autumn 2020, BCP Council successfully secured £525,000 of government Flood Defence Grant in Aid (FDGiA) to produce the strategy on behalf of the partners. We appointed specialist technical consultant AECOM to help support this work.
Coast protection schemes – The final adopted Strategy enables us to bid for government funding to deliver viable and realistic coast protection schemes to implement Shoreline Management Plan policy. Although there is no guarantee we’d receive 100% funding for schemes, it will help us to understand the level of partnership funding that may be required to deliver a scheme.
Strategy development – engagement and consultation
We have involved our stakeholders in the development of the Strategy since summer 2021.
During the fourth phase of engagement in winter 2022, the public and key stakeholders had their say on the proposed short list for managing coastal flood and erosion risks. Each of the options were then appraised to assess their economic, technical, environmental and social viability. The process identified the proposed leading options for each of the 18-option development units across the strategy area. These proposals were the focus of the fifth phase of engagement which ran from 5 June to 27 August 2023. Survey documents were made available online and at libraries across the strategy area, and an online presentation was given by members of the FCERM team on 27 June – the full 80 minute presentation is available at YouTube – Phase 5 Public Meeting. The feedback to this final phase of consultation was used to inform the Draft Strategy.
Next steps
The Draft Strategy was presented for formal adoption by all parties involved in its development:
- BCP Council’s Cabinet adopted the strategy in winter 2024
- The Environment Agency’s Large Project Review Group reviewed and approved the Strategy in spring 2025
- New Forest District Council adopted the Strategy in winter 2025.
The Final Strategy document will be made available on this website soon. It will take two forms; a full and technical version and a summary version.
We will then set about identifying a funding strategy to enable us to deliver schemes that will reduce the risk of flooding and coastal erosion across the strategy area.
Coastal flood risk
Coastal properties, infrastructure and assets can be at risk from flooding ie during periods of high tides combined with storm surges and wave overtopping. Due to climate change, sea level is predicted to rise by 1.03m over the next 100 years. This will increase the risk of coastal flooding by making extreme coastal water levels higher and more frequent. Flooding caused by storm events is expressed in terms of an Average Return Period in years, calculating the frequency and intensity of past events. It describes the severity of a storm event and these can sometimes occur more than once in the same year. A large storm event that occurs on average once every century is referred to as a 1 in 100 year event.
Coastal erosion risk
Coastal properties, infrastructure and assets can be at risk from erosion, i.e. potentially being lost to the sea through shoreline retreat or land sliding. Shoreline retreat is where coastline boundaries change because of waves and tides, sediment supply, precipitation levels and the effect of groundwater. Sea level rise alone will also significantly increase the risk of coastal erosion. Our risk modelling data shows that if we do nothing and let nature take its course, our coastline would on average* erode by up to 1m every year.
*Cliffs in the strategy area are complex (influenced by both toe erosion and groundwater) and tend to undergo infrequent but large-scale episodes of retreat by cliff slips and landslides. The losses to this type of erosion are averaged out to give a yearly retreat figure.
Defending the coast
To reduce the effects of coastal erosion on communities and the natural environment, a combination of various defence structures and natural features can be used. These measures fall into two main categories:
- Hard engineering uses man-made barriers such as sea walls, groynes and rock revetments to reduce the impact of waves on the coast.
- Soft engineering techniques such as beach renourishment, dunes and saltmarsh creation use natural materials, features and processes to absorb energy from the waves.
Many successful coastal management methods combine both hard and soft engineering techniques. In each case the effects upon coastal processes and the natural environment are fully explored before management decisions are made.
Despite everything that can be done there will always be some locations where it is not possible or appropriate to defend against coastal flooding/erosion or maintain existing defences. In these cases, communities need time and support to adapt to changes. It is also important to note that although property insurance against coastal flooding can be purchased, there is no insurance currently available for coastal erosion.
Environmental considerations
Coastal management can have a significant impact on geological features, wildlife habitats, coastal processes, landforms and heritage features. The conservation of these habitats and features in a changing environment remains a key aspect in terms of environmental sustainability. Future management of the coast needs to allow natural habitats and features to respond and adjust to change, such as accelerated sea level rise. It must also comply with the legislation relating to important conservation designations protecting many habitats along the coastal frontage.
Poole Bay, Poole Harbour and Wareham FCERM Strategy
In 2014, the Poole Bay, Poole Harbour and Wareham Strategy was adopted by the Environment Agency and its partners to identify how coastal flood and erosion risks from Swanage to Hengistbury Head , encompassing Poole Harbour and Wareham would be managed over the next 100 years, with an emphasis on the years up to 2030. You can find out more about the schemes being guided by this Strategy as part of the Poole Bay Beach Management Scheme.
The policy balances the risks with natural processes by assigning one of four different management approaches to each of the coastline areas:
- Hold the Line – maintain / upgrade / replace coastal defences in their current position where funding permits.
- Managed Realignment – manage coastal processes to realign the ‘natural’ coastline configuration, either seaward or landward of its present position.
- No Active Intervention (do nothing) – a decision not to invest in providing or maintaining defences or management of the coast.
- Advance the Line – a decision to build new defences seaward of the existing defence line where significant land reclamation is considered.