8 minute read
Havant 18
Eastoke, Hayling
Hayling Island
Delivering Successful Beach Management
Hayling Island has over 3 miles of beaches along the seafront facing the Solent and many more miles of shore around the Harbours of Langstone and Chichester. With a beach that has long stretches of sand below high tide mark and shallow waters at low tide, the destination is naturally popular with locals and visitors alike.
Coastal defence policy varies along the south coast of the Island. From a ‘Hold the Line’ policy in the east and centrally, to an area of ‘natural evolution’ at West Beach and Gunner Point.
One frontage that contains many residential properties close to the sea is at Eastoke. Coastal defences here are primarily made up of shingle and this material is managed in the form of ‘beach recycling’. Beach recycling is the movement of shingle from areas where it builds up by the waves and tides, back to those areas that have been eroded. This method of beach management has been identified in the South Hayling Beach Management Plan (BMP) and the strategy delivers a 1:200-year standard of protection for Eastoke. The BMP began in April 2017 funded by a £3.3m Environment Agency grant. The beach recycling strategy runs until April 2024 ensuring that the shingle takes the brunt of the waves, preventing coastline erosion, failure of the buried seawall and flooding to the properties along Eastoke. The area last flooded significantly in 1985, which pre-dates beach recycling activities, and the strategy has stood up to the growing concern of sea-level rise.
Recent Activity
Beach management works are usually undertaken to coincide with ‘storm season’ to ensure the beach provides an effective coastal defence. During the last financial year, several storms hit the south coast of England, including Storms Barra and Eunice. Two successful beach management campaigns were undertaken during this period including working in collaboration with Hayling Golf Club. Here, 15,000m3 of shingle was moved from Gunner Point back to Eastoke before the winter period began. Following the winter season, 20,000m3 of shingle was recycled helping to return the beach to withstand the risk of coastal flooding.
Sandy Point, Hayling
Big Wins for Hayling
Serious flood events to Eastoke properties have greatly reduced since Beach Management has been in place. An attractive beach is maintained for residents and visitors to Hayling - it’s an internationally recognised location for windsurfers, sailors and kite surfers. Annual beach recycling is currently more cost-effective than other coastal defences such as seawalls or rock armour.
Cllr Clare Satchwell, Cabinet Lead for Planning, Hayling Seafront Strategy and Coastal Management
Portsmouth
A city famed for its engineering, from the Palmerston forts that line the Solent to the modern architectural icon the Spinnaker Tower. Portsmouth bears a wealth of structures that stir pride within the people who call the city home.
Sited on Portsea Island, Portsmouth is surrounded by water. As we move into an age of sea level rise and more frequent storms, an expanse of engineering important to the city in both function and form is the city’s sea defences. Arguably its most important coastline is the south-facing coast known as the Southsea seafront. Southsea Coastal Scheme phase 1 under construction
Southsea Coastal Scheme After a year of the
A High Profile Programme construction…
Construction of the UK’s largest local authority led coastal defence project got underway in September 2020 and when complete, it will stretch for 4.5km, helping to reduce the risk of flooding to more than 10,000 homes and 700 businesses.
The Southsea Coastal Scheme is comprised of six frontages, from Old Portsmouth to Eastney, worth around £150M in total. Two frontages are currently being constructed along a coastline steeped in history stretching back many generations. Frontage 1, Long Curtain Moat, is due for completion in autumn 2022 and Frontage 4, Southsea Castle, got underway in January 2022. Long Curtain Moat
Tidal Pool establishing Tidal Pool with life 525 linear metres of sheet piles installed, totalling 6300m2. Laid end to end, this would make a total of 12km of sheet piles driven into the ground.
11,474 tonnes of heavy, dense anorthosite rock imported from Norway.
20,000m3 of dredged material laid.
10,200m2 of geotextile installed under the rock to prevent the rock settling into the existing beach revetment at Frontage 1.
Unearthing History
There have been several unexpected discoveries made during the works. The team uncovered the remains of the 17th century city walls and defences, as well as original masons’ marks inscribed on the stones. Working closely with Historic England and Wessex Archaeology, the finds have been recorded for posterity and a section of the original wall has been restored and will be a focal point of Long Curtain Moat. Works to protect the historic Long Curtain Moat have included repairs to the moat walls and an intensive steam clean. The cleaning process transformed the moat’s inner walls, removing much of the staining and restoring them close to their former glory.
Original masons’ mark
Matching Old With New
Throughout Frontage 1, materials have been meticulously sourced to ensure they closely replicated the original sea defences, with Purbeck limestone and granite units making up the new defences. Approval from Historic England for the materials to be used came after more than a year of consultation and testing to ensure the new design was sympathetic to the historic area.
Remains of the 17th Century city wall
Ecology and Recycling
Respecting the habitats of wildlife is a priority of the Scheme. The team worked closely with Natural England on mitigation strategies for dark-bellied brent geese that frequented the area. An area is now fenced off for the geese during winter.
As the work moves East along the front, the Scheme will schedule works around the purple sandpiper birds that overwinter around Southsea Castle. This scheduling will restrict disruption and noise to those months outside of when the birds inhabit the area.
Frontage 1 will also see the introduction of 18 tide pools amongst the defences that will help to promote the colonisation of marine life. The concrete pools are designed to create ecosystems that mimic natural rock pools found on rocky coastlines.
Recycling is also a priority, and a materials processing site has been set up to maximise this. The Scheme plans to reuse material that will be broken and excavated out of the existing structures to provide fill material for the new sea defences. This will avoid sending more than 92,000 tonnes of waste to landfill.
Stakeholder Engagement
The Scheme now has its own on-site project information centre where visitors can drop in. Regular stakeholder and community engagement activities have been carried out since it’s opening and a customer engagement officer has been employed to help increase corporate social responsibility. Site visits for stakeholders are often organised, as well as visits to schools and learning events focused on STEM (Science, Technology, Engineering, Maths).
Portsmouth’s coastal defence project for the north of Portsea Island, covers 8.4km of Portsmouth’s coastline from Tipner through to Milton. Most of the area is low-lying and many of the current coastal defences are approaching the end of their effective lives.
The new scheme is designed to a 1 in 500 year (plus allowance for climate change to 2100) standard of protection against flooding, reducing the risk of flooding from the sea to over 4,200 homes, 500 businesses, and critical infrastructure including the Eastern Road over the next 100 years.
North Portsea Island Coastal Defence Scheme
Slipway during construction Section of Glass Floodwall
Ecoformliner wall in place at North Portsea Island, phase 4
The story so far
In 2014, the government awarded £58m of funding to the North Portsea Island Scheme. Construction began in 2015 and the entire scheme is due for completion in autumn 2025.
The scheme is being delivered in 5 phases. Phase 1 Anchorage Park and 2 Milton Common were completed in 2016. Phase 3 Tipner Lake, along the northwest coast of Portsmouth started in 2017, with completion and open to the public in September 2019.
In November 2019 work on phases 4a Kendall’s Wharf and 4b Eastern Road along the east coast of Portsmouth began. The first stage, 4a, which ties in with the completed defences at Anchorage Park, included the construction of an earth embankment, road raising at the entrance to Kendall’s Wharf and a timber cladded steel sheet pile wall. A new raised coastal footpath was built, raising the land levels to provide protection against flooding with approx 2,000m2 of wildflower seeds and 75 new trees planted alongside. Phase 4a was completed in spring 2021.
Phase 4b began in 2021 and covers the longest stretch of this phase which will tie in with the completed defences at Kendall’s Wharf and Milton Common.
