Mumbles Coastal Protection Scheme

LOCATION:

Near Swansea, West Glamorgan

Coasts & Ports

Currently under construction, this £23m project involves coastal protection works along Mumbles Promenade. The improvement works will provide enhanced flood and coastal erosion protection to businesses and residential properties currently at long-term risk of flooding.

Our collaborative involvement with the scheme began at ECI stage when we were invited to provide budget, buildability and logistics advice for each design option. We proposed a methodology and plant schedule to support the Marine Consent Licence application.

Mumbles is currently protected by two types of coastal defences – a 0.5km mass concrete vertical sea wall and a 0.7km sloping revetment structure. Some of these defences were built over a century ago.

Our works comprise:

Construction of a concrete faced, concrete stepped apron and sheet pile toe wall. This will extend 4.5m to 5m forward of the existing wall. The stepped revetment is installed to a depth of 1m. A steel sheet pile toe will be installed. The wall is being faced with specially designed panels to enhance biodiversity.
Construction of a new concrete revetment. The slope and alignment matches the existing but the footprint will extend further onto the foreshore.
Raising of the promenade structure up to around 0.5m in the middle section, as it currently dips gradually from both ends. The promenade will also be widened to create a segregated pedestrian footpath and cycleway.
Public realm improvements including seating, views and connectivity, with enhanced hard and soft landscaping.

Challenges

The works are in a busy, high-profile area and attract significant public interest.

The project is adjacent to Blackpill SSSI, designated for its importance as a habitat for local and migratory birds.

Name Surname
Job role on project

Solutions

We meet face-to-face with residents and businesses to inform them about the project’s progress and address concerns. We have taken a proactive and collaborative approach to engaging with the community including:

Working with Swansea Council’s Beyond Bricks and Mortar scheme to provide trainee/apprentice placements.
Developing our approach from our previous project at Sandy Bay, we worked with the council, local schools, community groups and a multimedia company to produce the ‘Mumbles Sea Through Time’ educational programme.
Held a ‘Meet the Buyer’ event to engage with local suppliers.

The key risk is pollution to the foreshore. so we have developed pollution prevention plans including emergency response. All plant uses biodegradable oil. Weepholes in the original sea wall are checked for the presence of birds prior to works commencing. Any at risk of becoming inhabited are filled or covered.

During the ECI stage we collaborated with Swansea University’s Sea-Hive project to trial a variety of hexagonal tiles to determine the design that best supported biodiversity. We installed thirteen different tiles on the sea wall, with the university monitoring the marine species that populated each one. The most effective pattern was selected and is being installed on the new sea wall.