Clevedon Marine Lake Sea Wall: Phase 1 & 2

EJ McGrath repaired the Marine Lake sea wall at Clevedon for North Somerset Council, delivered across two phases.. The wall is a working flood defence as well as a heritage seafront structure, so both phases were self-delivered by our own teams in a live, tidal environment -with the promenade and Marine Lake kept open throughout. The two halves of the job called on very different skills: traditional masonry conservation on one, modern marine concrete repair on the other.

EJ McGrath’s role

EJM self-delivered both phases with our own teams – heritage lime-mortar masonry on one, intertidal concrete repair on the other – planning all access, plant and sequencing around the tide and continuous public use. Keeping the work in-house meant one team, one standard and clear accountability across two very different sets of skills.

Phase 1 – The boundary retaining wall- Masonry Repairs

The first phase restored the historic sea wall at Poets Walk, a Victorian stone masonry structure dating from the creation of the Marine Lake. This was conservation work: bring the wall back to good order with traditional materials and methods, without losing its character.

• Re-pointed and repaired in NHL5 hydraulic lime mortar to match the original
• Replaced around 82 metres of coping and facing stone, like for like
• Made good roughly twenty missing stones
• Opened no more than ten metres of wall at any one time to keep the structure and the public safe
• Kept the promenade and Marine Lake open throughout, with no direct vehicle access — all materials and plant planned in carefully

Phase 2 – Marine Lake seaward wall -concrete repairs

The second phase moved onto the seaward face of the Marine Lake itself – a 1920s concrete wall with a stone facing, where years of exposure had opened up voids across the face. We carried out around repairs in Fosroc Renderoc HB45, working in the intertidal zone right at the water’s edge.

The defining challenge was the tide – and unusually, it came from both sides: the sea advancing across the beach in front, and water overtopping into the lake and back over the wall from behind on an offshore wind. With no easy way to reach the face, we engineered our way around it rather than forcing the programme:

• A floating pontoon with a fixed tether line run along the lake wall
• Custom-fabricated lightweight aluminium access platforms to reach every repair area safely
• Every shift planned against the tide tables, with the site supervisor adjusting daily to the actual weather, swell and sea state

Timing mattered as much to the quality of the concrete repair as to the safety of the team: catch a pour or a cure on the wrong tide and you lose the work. We didn’t.

Outcome

A sound, repaired wall — delivered on budget and ahead of programme. Across the two phases we brought heritage masonry and marine concrete repair together on the same stretch of Clevedon seafront: both flood-defence assets, both repaired in live, tidal, publicly used surroundings, and both self-delivered by our own teams. It’s the kind of constraint-led coastal work that keeps North Somerset Council bringing us back to the seafront.