Land & Water Services Ltd were employed by Associated British port’s to undertake coastal flood bund repair works at Cobnor Point, Chidham, West Sussex.
The bunds were eroding due to winter storm damage and over-topping at high tides. The design called for the installation of a heavy duty post & rail system to protect the inner face of the bund & a high performance matting to cover and protect the side bund when over-topping.
The system consisted of 3M long x 150mm square oak posts driven into the ground at 1M centres, 2 metre’s deep, along the full length of the inner side of the bund, PVC coated steel mesh panels were then fixed to the inner side of the posts with an oak walling fixed to the top of the posts, stone rip-rap was then installed into the bund to a 1M hight behind the mesh, a heavy duty non-woven geotextile was used for separation & filtration. A layer of top soil was used to reform the slopes between the inner post & rail system and the footpath timber edging, a coastal grass seed mix was applied to the soil and covered with coir erosion protection blankets.
A row of preplanted coir rolls were also installed at the bottom of the newly installed post & mesh system, these, in time, will help to provide an extra vegetated protection system to the inner side of the flood bund…..
Terraqua supplied all the erosion protection materials to complete the works……
At high tide the side bund of the lagoon over-tops causing major erosion problems and flooding.
The side bund was reformed and covered with an anchored reinforced vegetated system (ARVS). The system is engineered to provide a long-term design life, the PP5 Xtreme system consists of a lightweight high performance turf reinforcement mat( HPTRM) layer and earth percussion anchors that work together to lock soil in place to resist movement for permanent erosion protection for hydraulic & non-hydraulic vegetated applications.