Portsmouth 22

More than just a wall

Most of the sea defence wall along the Eastern Road will be a textured wall using a special ‘Ecoformliner’ mould, which imprints into the wall during construction. As such, the texturing is part of the actual sea defence and has a 100-year design life. Coastal Partners worked with experts including the Universities of Glasgow and Bournemouth to design the mould for the project. Once established, the textured seawall aims to provide a platform for the many marine species found in Langstone Harbour to colonise on and is the first specifically designed for inter-tidal ecology in the UK.

As well as environmental benefits, the marine plant growth on the sea wall is expected to have practical advantages. Once established, the vegetation should absorb wave energy, reduce temperature fluctuations and reduce salt ingress and egress into the local ground water to create a more stable environment.

For phase 4b the team also worked with residents and stakeholders to include a glass topped flood wall as part of the planned sea defence scheme. As a result of the collective efforts and through efficiencies within the budget, funding was found for a total of 400 metres of glass flood wall to be installed in 3 different locations: the Andrew Simpson Watersport Centre, Harbourside Park and Tudor Sailing Club. By the end of construction year 2021, a total of 600m of sea wall was completed and the first two sections of glass flood wall were successfully installed in the area around Tudor Sailing Club and the Andrew Simpson Watersports Centre. Both venues had their slipway replaced and raised to meet the required defence level.

Ecoformliner wall during construction

What’s to Come?

A sheet pile wall to help form the base for the flood wall

Continuing of full height concrete flood wall, including Ecoformliner

Installation of third flood glass section and new improved fencing at Harbourside Holiday Park

Landscaping work, including the new wider coastal footpath, new seating areas and more wildflower and trees

Environmental protection

Respecting nature is a priority of the scheme, and the team works closely with Natural England to not only preserve, but shape and enhance the landscape to create more habitats for wildlife and marine life. Langstone Harbour is an extremely special natural area and as part of the Solent, one of the most important coastal zones in the UK - providing a nationally and internationally recognised and protected overwintering zone for waders, ducks and geese.

The Solent supports a large dark-bellied brent geese population every winter. To ensure our scheme does not cause any unnecessary disturbance to these and all other coastal birds in Langstone Harbour, all construction work stops during this period, recommencing again in the spring.

Other phases of the project will be going through Detailed Design review and planning applications later this year. The entire scheme currently has a planned completion date of 2025. A bee post similar to those being installed at phase 4

Gosport

Holding back the tide

With its great views of the Isle of Wight and sweeping shingle beach, Stokes Bay is a popular destination with locals and visitors alike. After enduring the sea’s power twice daily, the 1974-built flood defences along it’s coast are now reaching the end of their serviceable life and are in need of an upgrade. Coastal Partners, as part of Gosport Borough Council, are working in partnership with Hampshire County Council, to develop a longer-term solution to manage coastal erosion at Stokes Bay, given the high costs associated with ongoing maintenance and repairs.

Stokes Bay Option Appraisal and Outline Design Study

Fort Gilkicker, Stokes Bay Aerial view of Stokes Bay

The Study sets out to find the best and most practical solutions to protect key infrastructure from flooding and erosion. Transport, tourism, heritage and the environment are all key themes being considered to understand the most suitable options for the shoreline on the southwest coast of the Gosport peninsula.

The study focusses on the area between the Alverbank east and Alverbank west car parks, but integration of the wider Stokes Bay frontage will also be factored in when developing the Flood and Coastal Erosion Risk Management options. Similarly, the study will identify wider objectives shared with our partners and stakeholders.These include regeneration, growth and wellbeing, and with their inclusion it will establish a more holistic view that supports both the community and the environment.

With funding for the Study obtained from the Southern Regional Flood and Coastal Committee, Gosport Borough Council and Hampshire County Council, the project is currently identifying a short list of options that will be investigated further before a leading option is chosen.

Discussions are being held with Gosport Borough Council and Hampshire County Council to identify what option(s) would be preferred before moving to the next stage of the project which will involve discussions with other key stakeholders.