Coastal Protection – Mackley Engineering https://mackley.co.uk Engineering a Sustainable Future Tue, 07 May 2024 15:50:53 +0000 en-GB hourly 1 https://wordpress.org/?v=7.0.2 https://mackley.co.uk/wp-content/uploads/2023/09/mackley-logo-dark.svg Coastal Protection – Mackley Engineering https://mackley.co.uk 32 32 Thorney Island Emergency Works https://mackley.co.uk/coastal-protection/thorney-island-emergency-works/ Tue, 07 May 2024 15:50:53 +0000 https://mackley.co.uk/?post_type=coastal_protection&p=7447

The Environment Agency recently required assistance with a tidal flap valve structure on Thorney Island. The outer two of the three valves had failed, leading to severe flooding on the island at high tide which was cutting off access for 2,000 residents.

Work immediately started on this emergency Design and Build project. Our Technical Services Team designed an innovative solution which effectively cantilevered out from the structure allowing the replacement valves to be installed from the top, without impacting the operations of the centre flap valve. In just a few weeks, we had designed, procured, imported from the Netherlands and installed the specially fabricated valves, much to the relief of the MOD who owns the land.

The CPP, Method Statements, RAMS and designs were all submitted and approved by the Principal Designer prior to any works and further flooding was prevented, all within 4-5 weeks! Since then, we have replaced the centre flap valve and final inspections and reinstatement are in place.

We were really impressed with the speed Mackley responded to the flood incident on Thorney Island following Storm Ciaran. Mackley gave us an ambitious timeline to design and construct a bespoke solution for the failed asset and they delivered as promised.

Marc Pohl, Senior User – Thorney Island Habitat Creation Project
]]> Medmerry Managed Realignment https://mackley.co.uk/coastal-protection/medmerry-managed-realignment/ Thu, 03 Aug 2023 11:17:51 +0000 https://mackley.co.uk/?post_type=coastal_protection&p=451
PROPERTIES
PROTECTED

348

LArgest
IN UK

Realignment

HABITATS
CREATED

183Ha

MONEY
SAVED PER YR

£300,000

climate
change

Resilience

winner
of

20+ Award

early
colonisation

New intertidal habitats

improvements
to

Public amenities

Medmerry is an excellent example of how we create a sustainable legacy; protecting communities whilst working with nature. ‘Managed realignment’ involves building new defences inland from the coast and allowing a new intertidal area to form landward of the new defences. ‘Intertidal’ refers to the land that is exposed at low tide and covered by the sea at high tide.

The flood defences we constructed offer 1,000 times better flood protection than previous defences, and provide flood protection against rising sea levels over the next 100 years.

The project involved:

  • 7km clay flood embankment
  • 8km of access tracks and drainage ditches
  • 8 concrete flood control structures
  • 2 protective rock armour revetments

The uniqueness, scale and innovative ecological approaches within this scheme influenced future Environment Agency policies on the economic and environmental benefits of managing coastal flood risk.

Providing flood defence and creating environmental benefits

Our teams’ expertise in hard and soft engineering meant that habitat enhancements were at the centre of this project. For example, we used a 3D model to make best use of surplus material to form bird nesting islands. We also used Prolec GPS equipment to meet the challenge of excavating new areas of saltmarsh, accurately guiding the excavators to successfully create varying levels for the flora habitats;

We created water vole habitat over 2km of ditches using plug planting and pre-planted coir rolls, and used award winning mitigation for ground nesting birds using a ‘push-pull’ method which provided suitable habitat for key species within the 350Ha site at all times.

Saving resources through innovation and minimising global impacts

Our final cut and fill balance was virtually zero and we re-graded site won material to save 10,000m3 of imported clay which would have otherwise required over 1,000 lorry movements and their resulting carbon emissions.   

Fitting into and enhancing the local community

We kept the wider community involved through a multi-media campaign, as well as volunteer input into archaeological works and visits by local schools, national and international engineering organisations.

We set up the Medmerry Stakeholder Advisory Group to bring together local residents, farmers and other bodies. We all worked together to maximise benefits to the community through various designs and landscaping. We also included the RSPB as a full project partner to be involved with our programming and to complete mitigation. They now manage the site as a publicly accessible bird reserve;

“This project will become a thriving wildlife haven and a big draw for nature lovers. We should take confidence from the success here at Medmerry and help to secure our and nature’s future by investing in these sort of landscape scale projects.”

Mike Clarke, RSPB Chief Executive

]]> Elmer Beach Management Scheme https://mackley.co.uk/coastal-protection/elmer-beach-management-scheme/ Thu, 03 Aug 2023 11:17:22 +0000 https://mackley.co.uk/?post_type=coastal_protection&p=450
revetment
extension

170m

TONNes of
ROCK

20,000

DREDGED
SHINGLE

15,000m3

BOAT
RAMP

30m

PROPERTIES
PROTECTED

325

Mackley, working as part of Team Van Oord, installed a new 20,000tonne rock revetment, repaired Elmer’s coastal outfall and placed 12,500m3 of shingle on the beach, protecting 325 homes. All works were safely completed throughout the Covid-19 lockdown. 

We worked closely with our Client, the Environment Agency and managed the ECI, design and approvals process . We also engaged with local people and enhanced community facilities by including a new boat ramp in the scheme.

Innovation and aesthetics

The new 30m boat ramp was made from reinforced concrete units that were cast on site. The design included Dycel blocks on the top which have holes that help dissipate wave energy. We also carried out an extension to the existing outfall through the new revetment, with timber cladding for protection and aesthetic appeal.

Adding biodiversity and social value

The scheme involved a unique and innovative ‘Greening the Grey’ scheme for the rock revetment. The result is an ecologically enhanced revetment which will create a wildlife environment for a wide variety of sea creatures and life-supporting vegetation. The Cornish Granite shipped from Falmouth on barges provides the primary armourstone layer. This was interspersed with 5% Boulogne Limestone also delivered on barges, to encourage ecological development within the intertidal zone. A secondary armourstone layer of Boulogne Limestone provides shaded and sheltered habitat to encourage ecological growth of biodiverse species.

Collaboration with the Client and supplier

Mackley worked with the Client, RHDHV, rock suppliers and Glasgow University to design the rock revetment. During delivery, we worked closely with KML for the rock supply and Boskalis who dredged and ‘rainbowed’ the shingle from an offshore shingle bank to just offshore ready for collection at low tide by our dumper trucks.

Public safety and stakeholder engagement

Work was tidal and involved some evening and night work, however our monitoring of noise and vibration meant that local residents were not disturbed. As this area is a very popular spot for locals, we improved the footpath for beach users and new seating was added in the form of rock benches and sculptures created by re-using some of the old timber groynes.

While we were there…

Recent storms had damaged some of the frontage causing the coastal walkway to be only 3m away from a breach. While we had the equipment and operatives on site, we carried out emergency works to repair the damage and shore up the walkway.

]]> North Portsea Island Coastal Defence Scheme Phase 4 https://mackley.co.uk/coastal-protection/north-portsea-island-coastal-defence-scheme-phase-4/ Thu, 03 Aug 2023 11:15:58 +0000 https://mackley.co.uk/?post_type=coastal_protection&p=449
New defences

2.8km

coastal path

3km

social spots

11

winner
Climate change resilience
Value engineering
Greening the grey – Innovative textured sea wall
Steel piling
Road raising
Clay flood embankment
Internationally designated wildlife sites
Public realm enhancements
Excellent community engagement

Award winning coastal flood defences for North Portsea Island

Mackley originally delivered Phase 1 of this 9 year programme to improve Portsmouth’s resilience to climate change. Off the back of this, we were awarded the contract for phase 4. to improve flood defences along Eastern Road, protecting residents and businesses in North Portsea.

The value of good engineering

Mackley’s value engineering improved buildability, made use of locally sourced materials, reduced risk to nearby structures, significantly reduced disruption to neighbours and improved pedestrian safety. Our Engineers also led comprehensive early testing of the new concrete sea wall design, working closely with all of our delivery partners. 

Keeping adjacent businesses operational

Through our ingenuity and positive communication we kept the adjacent concrete batching plant operational throughout the works, installing a temporary access road and modifying the batching infrastructure.  By including temporary parking for HGVs, we also reduced an ongoing issue of delivery lorries queuing in Eastern Road.

Adding biodiversity and social value

Greening the grey was a key part of the design, with industry leading textured surface for the new concrete sea walls. This is an innovative approach to increase colonisation by marine organisms, transforming the wall into a valuable habitat that simultaneously protects the concrete behind from the sun and sea. 

The scheme also includes an improved 3km coastal path with 11 social spots, encouraging healthy lifestyles and making this section of Langstone Harbour a welcoming environment for the local community.

]]> Hythe Ranges Sea Defences https://mackley.co.uk/coastal-protection/hythe-ranges-sea-defences/ Thu, 03 Aug 2023 09:07:34 +0000 https://mackley.co.uk/?post_type=coastal_protection&p=434
contractor led

Design & build

working in

An active firing range

protecting

Historic structures

innovative

Biodiversity & Enhancements

protecting

Wildlife & SPA site

Working with our parent company Van Oord UK for the Environment Agency, we constructed defences along 3.4km of the Kent coastline.

The site works commenced just after the Covid-19 lockdown, so the team adapted quickly to form a bubble, found innovative ways of collaborating remotely and made excellent progress throughout the following year.

Working together to solve project challenges: 

Working in an active firing range: As an active military training site, the works were carefully planned alongside the MoD in accordance with the army shooting programme, keeping their site operational throughout construction.

Historic Structure Protection

Protecting Martello Towers and the historic Dymchurch Fort: Hythe is one of the oldest MoD firing ranges in England, operational since Napoleonic times. As a result of this centuries long military presence, our team had to carefully control construction methods to protect the Dymchurch Redoubt Scheduled Ancient Monument, 2 Scheduled Martello Towers, 1 listed Martello Tower and 7 other heritage defence features.

Excellent programme management

The entire design and build programme was focused on Van Oord’s shingle delivery as this was the highest cost and highest risk activity. All other elements were completed to tight timeframes to make sure the site was ready to receive the huge shingle recharge volumes. 

Biodiversity enhancements

The Environment Agency and our staff were keen to maximise biodiversity benefits. We cut over 80 rock pools in in the rock revetment and included habitat features on the new groynes – each providing niches for wildlife. The features are part of a long term study by the University of Bournemouth and are showing early signs of colonisation by marine life.

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