Compared to hard engineering, soft engineering approaches are less expensive, are more long-term, attractive and sustainable as they work with natural processes. Below we explore some of the soft engineering techniques available in managing coastlines.
Beaches are made higher and wider by importing sand and shingle to an area affected by longshore drift.
Cheap, retain the natural appearance of the beach and preserves the natural appearance of the beach.
Offshore dredging of sand and shingle increases erosion in other areas and affects the ecosystem. Large storms will require beach replenishment, increasing costs.
Managed retreat (coastal realignment)
This is when areas of the coast are allowed to erode. This is usually in areas where the land is of low value.
Managed retreat retains the natural balance of the coastal system. Eroded material encourages the development of beaches and salt marshes.
People lose their livelihood e.g. farmers. These people will need to be compensated.
Depends on the amount of compensation that needs to be paid to people affected by erosion.
Dune regeneration involves taking action to build up dunes and increase vegetation. This helps to strengthen the dunes and prevent coastal retreat. New sand dunes can be created to protect from coastal flooding. Often, marram grass is planted to hold the dunes together. Wooden boardwalks can be built to encourage people not to walk on the dunes.
Dune regeneration and boardwalk
Dune regeneration provides a barrier between land and sea, wave energy is absorbed and stabilisation is cheap. It also maintains a natural looking coastline.
During dune regeneration, the land needs to be carefully managed so that any new vegetation that is planted is appropriately protected from trampling by humans. This could involve temporarily fencing off the dunes or by providing wooden walkways. It can also be damaged by storm waves.
Beach reprofiling involves redistributing sediment from the lower part of the beach to the upper part of the beach.
Cheap and simple and reduces the energy of the waves.
Only works when wave energy is low and needs to be repeated continuously.