Monmouthshire and Brecon Canal Breach

Works to repair a serious breach of the Monmouthshire & Brecon Canal including some 1.5km of relining works.

Access points onto the canal bed were formed and the canal bed drainage and haul road construction were installed as works progressed.  Canal bed drainage outfalls were installed through the embankment using directional drilling whilst all excavated material from the canal bed was transported to an adjacent field where it was processed using lime to stabilise into a usable fill material for the breach.  Approx 4500m³ of stabilised material went back into the breach repair where it was compacted in layers incorporating soil reinforcement mesh.

The canal embankments were shaped to the required batter prior to the lining works which consisted of a 1.2mm thick PVC-P membrane, welded to form a watertight seal, placed on top of a protective fleece layer.  Another protective fleece layer was then placed over the membrane prior to receiving 125mm of concrete as further protection.  Concrete was placed in 80m sections with the use of a concrete pump.

The works were completed with interlocking revetment blocks on the offside, infilled with excavated material, and retaining blocks used on the towpath side prior to backfilling, reinstating the towpath and access points, planting of aquatic vegetation.