Soft Engineering
Soft engineering approaches (beach nourishment, cliff regrading and drainage, dune stabilisation) attempt to work with physical systems and processes to protect coasts and manage changes in sea level.
- This attempts to work with natural physical systems and processes to reduce the coastal erosion and flood threat.
- Usually less obvious and intrusive at the coast
- May be cheaper in the long term
- Not suitable for all coasts
Beach Nourishment
- Artificial replenishment of beach sediment to:
- replace sediment lost by erosion,
- to enlarge the beach
- so that it dissipates wave energy and reduces erosion and
- increases the amenity value of the beach.
- replace sediment lost by erosion,
- £20 million per km of beach
- Ongoing costs are high
- Sediment must not be sources from elsewhere in the sediment cell
Cliff Regrading and Drainage
- Cliff slope angles reduced to increase stability
- Re-vegetated to reduce surface erosion.
- In-cliff drainage reduces pore-water pressure and mass movement risk.
- Costs of £1 million per 100 m
- Can be disruptive during construction
Dune stabilisation
- Fences are used to reduce wind speeds across the dunes,
- dunes are then replanted with marram and lyme grass to stabilise the surface
- This reduces erosion by wind and water.
- Fencing costs £400-2000 per 100 m and replanting £1000 per 100 m (1400-3000)
- Can be very cost effective in the long term.