CURRENT PROJECTS

Christchurch Bay and Harbour FCERM Strategy

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.

Christchurch Bay & Harbour aerial panorama

LEAD AUTHORITY

BCP Council

WORKING WITH

START DATE

July 2021

LAST UPDATED

July 2021

FCERM Strategy Overview map

Get involved!

Online survey – Read our information document and complete the survey which is open until midnight on 15th August 2021. Have your say

Interactive map – Pin your photos, comments and ideas for this stretch of coast to the map. Historic photographs of our beaches and cliff tops can really help us to document changes in coastal features over time. Have your say

Coasts for kids summer activity – Help your children learn about coastal dynamics by watching the five short animated videos. Choose a section of Christchurch Bay or the Harbour that interests you most, and make a list of the issues that you think should be considered by the strategy.  Add your suggestions to the survey and/or interactive map where your friends can see your comments and add to them!

A new strategy

Bournemouth, Christchurch and Poole Council (BCP) and New Forest District Council (NFDC) are working together with the Environment Agency to produce a new strategy to protect coastal communities from tidal flooding and erosion risk. It will guide how the frontage from Hengistbury Head to Hurst Spit, encompassing Christchurch Harbour, will be sustainably managed for the next 100 years.

As Coast Protection Authorities, BCP and NFDC have permissive powers to enable management of coastal erosion risk where it is appropriate and feasible to do so. In addition, along with the Environment Agency, BCP as Lead Local Flood Authority (LLFA) has statutory responsibilities for managing flood risk; Hampshire County Council are the LLFA covering the NFDC area.

In Autumn 2020, BCP Council successfully secured £450,000 of government Flood Defence Grant in Aid (FDGiA) to produce the strategy on behalf of the partners. We have appointed specialist consultant AECOM to help support us in this work and we anticipate the final strategy will be adopted by Spring/Summer 2023.

The strategy area

The strategy area stretches from the Hengistbury Head Long Groyne to the western end of Hurst Spit and encompasses Christchurch Harbour up to the tidal limits of Tuckton Bridge on the River Stour and Knapp Mill on the River Avon.

We have divided the coastal frontage into five distinct areas to help us identify how we can manage the flood and erosion risks in each of these areas. These areas may change as we develop the strategy, but they currently are:

  1. Christchurch Harbour
  2. Mudeford Sandbank
  3. Christchurch beaches and cliffs
  4. Naish Cliff and Barton-on-Sea
  5. Hordle Cliff and Milford-on-Sea
SMP2 Policy Summary Map

The coastal management approaches are indicated on the Poole and Christchurch Bays Shoreline Management Plan (SMP) Policy Map. They take account of existing defences and the natural and built environments.

The coastal management approaches are indicated on the Poole and Christchurch Bays Shoreline Management Plan (SMP) Policy Map. They take account of existing defences and the natural and built environments.

The new strategy seeks to address the broad issues and develop viable schemes to implement SMP policy and manage the coastal flooding and erosion risks across the whole frontage in a sustainable way.

Map 1 – Christchurch Harbour

PDZ1 Map 1 Christchurch Harbour

The policy varies for the area around the harbour but it can be broadly summarised as continuing to defend the areas which are currently defended (on their existing or realigned positions) and allow the undefended areas, such as the river estuaries and marshes, to continue to evolve naturally. We aim to work collaboratively with the Environment Agency and private landowners to co-ordinate a programme of flood defence works on the River Stour and Avon and create new wildlife habitats where opportunities arise. We also need to address the issue of the historic landfill site at Stanpit Marsh.

Map 2 – Mudeford Sandbank

PDZ1 Map 2 Mudeford Sandbank

The policy is to prevent a breach of the sandbank and manage the natural rollback of it into Christchurch Harbour as sea levels rise. This will be supported by the planned repair and upgrade of Hengistbury Head long groyne, repositioning the existing beach huts and addressing and maintaining the entrance to Christchurch Harbour.

Map 3 – Christchurch beaches and cliffs

PDZ1 Map 3 Christchurch Beaches and Cliffs

The policy along the length of coast from Mudeford Quay to Chewton Bunny is to hold the line which can be achieved by sustainably topping-up beach levels to reduce the risk of coastal erosion. However, Friars cliff may need additional measures to prevent the area from receding. We will also need to address cliff stabilisation at Highcliffe and the future outflanking risk of Highcliffe’s coastal defences caused by the continued recession of Naish Cliff.

Map 4 – Naish Cliff and Barton-on-Sea

PDZ1 Map 4 Naish Cliff and Barton on Sea

The policy for this stretch of coastline’s policy is for managed realignment.  It will underpin the potential to introduce schemes to help slow the rate of coastal erosion. Cliff top losses will continue to occur in the short and long-term so this will require adaption of the affected cliff top. We aim to work with private landowners to identify cost-effective actions and continue cliff monitoring at Barton-on-Sea to help inform future options.

Map 5 – Hordle Cliff and Milford-on-Sea

PDZ1 Map 5 Hordle Cliff and Milford-on-Sea

The policy for the western side of Milford-on-Sea is aimed at managing the transition between the retreating, undefended section and the defended areas to the east. To the east, at the strategy boundary, the policy is managing the transition to the Hurst to Lymington Project, as well ensuring coastal processes are strategically considered in the eastern side of Christchurch Bay and towards Hurst Spit. 

The benefits of a strategy

Having an adopted Flood and Coastal Erosion Risk Management (FCERM) strategy will enable us to seek and secure the required partnership funding for future coastal defence works. These will help lessen the risk of flooding or erosion in the Christchurch Bay and Harbour areas.

The risk of doing nothing

 Our risk modelling data shows that if we let nature take its course, our coastline would on average* erode by up to 1m every year. We must also plan for the effects of climate change, such as sea level rise and increased storminess. Together, these events are likely to result in an increased risk of significant numbers of residential and commercial properties being lost to future erosion, along with highways and supporting infrastructure.

*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. 

Managing coastal erosion

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 erosion/flooding 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 tidal/coastal flooding can be purchased, there is no insurance currently available against 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.