17th May 2018

Saving Our Coastline

Saving Our Coastline

Happisburgh, in Norfolk – known to locals as Norfolk’s disappearing village – has lost a large amount of its cliffs, the most within the region, due to the sea defences falling into disrepair and passing the point of salvage. If Happisburgh, and other villages like it, have any hope of preserving their coastline, we must establish new ways to reduce the rate of coastal erosion in the UK.

Coastal erosion has always been a constant battle. However, in recent years there has been many new ideas and with the advancement in technology we are becoming more efficient in not only protecting our coastlines but using sea defences to develop a renewable source of electricity, known as hydroelectricity. There are four types of coastal erosion; Hydraulic action, Abrasion, Attrition and Solution.

The main cause for coastal erosion are large waves produced by high winds and storms which eat away at the base of the cliff causing an overhang. Once the base of the cliff has been eroded too much, it will collapse over the stress of its own weight.

Another common cause of both coastal erosion and flooding is high tides, often spring tides when the tides are at their highest. This affects coastlines that are prone to being at sea level or flat areas with a lot of rivers and lakes.

Many different types of sea defence strategies have been developed, from a standard Timber Groynes to more advanced Hydroelectric sea defences such has the Tidal Lagoon, Swansea Bay, Wales. Timber Groynes have high advantages such as reducing the removal of the sand on the beach when longshore drift occurs which acts as a natural sea defence by preventing the waves from reaching the base of the cliffs. A disadvantage to using Timber Groynes are they have a short-term life span and have a high ongoing maintenance cost, although mentioned as an advantage, preventing longshore drift is also a disadvantage as it can lead to a reduction of sand further downshift allowing more erosion and less of a defence.

According to Marine Energy Wales, The Tidal Lagoon, Swansea Bay is estimated that it will power 155,000 homes for up to 120 years, along with creating new habitat, sea reefs and seabed sanctuaries. This shows the Tidal Lagoon is set to not only be a renewable source of electricity but will contribute to protect our coast lines and create a sanctuary for the subsea animals.

With the reduction of land mass caused by erosion, it is essential we develop new and innovative ways to protect our coastal towns and villages, whilst looking at cleaner, more sustainable ways to harness energy from the sea.

At HA Consulting Engineers, we take a keen interest in coastal erosion and are committed to protecting our harbour and river defences. Over 80% of our marine engineering projects are centred on the repair and refurbishment of existing harbour and waterway infrastructure. Updating these structures requires a rapid investigative process followed by an innovative and flexible approach to problem-solving.

To speak to us about our latest marine engineering projects, or for further information please get in touch.

Dan Bonham – Design Engineer, HA Consulting Engineers Ltd