CHAPTER 10: COASTAL PROCESSES, PATTERNS AND LANDFORMS
Soft coastal protection methods Soft methods work with nature rather than resist it. Wexford County Council used a variety of soft engineering techniques including dune reclamation, sand fencing and marram grass planting in an attempt to trap sand and slow the erosion of the beach and dunes.
Winter storm waves overwhelmed many of their attempts to protect the shore. The council then had to use hard rock banks (revetments) and rock armour in order to prevent the immediate threat of further coastal erosion. Soft engineering techniques may be used on the dunes north of the river delta where erosion rates are lower and there is less pressure on the beach and backshore area.
Fig. 47 Revetments and rock armour protecting the coast at Courtown, County Wexford
Several alternative beach protection methods have been considered but not constructed: 1. Beach nourishment
2. Groynes 3. Offshore breakwaters
No method on its own would be enough to cure the problem. The council has considered a number of options to provide the most suitable method of protecting this valuable stretch of coastline.
Some of the options that were identified by initial surveys of the coast at Courtown are described below.
Beach nourishment This is when sand is added to the beach to replace that removed by longshore drift. Sand is pumped onto the beaches from sites under the sea off the coast. However, a beach nourishment scheme would be affected by the process of longshore drift. The rate of loss of beach material would be such that the maintenance cost would be too high.
Groynes These walls are built at right angles to the shoreline and placed in a line stretching up and down the beach. They trap sediment carried by longshore drift.