Tuesday, 5 January 2016

Coastal Management Strategies - Rock Armour, Riprap, Sea Wall


Managing our coastlines is a very important subject, as the physical effects of the waves crashing up against the land can cause problems such as erosion and long shore drift. Thankfully, several management strategies were founded, allowing us the means to control these natural processes.

There are two main categories of coastline management strategies, ‘hard’ and ‘soft’ management. 

Hard engineers will normally cost more money, are quick to be put into action and are sometimes only used as a short term fix that may visually and physically affect the environment. The other option is ‘soft’ engineering techniques, which are comparatively cheaper and are normally executed with a more long term and sustainable view.

Rock armour is generally considered as a ‘hard’ method, and is sometimes used in rough areas where there is little alternative option than to protect the coastline long term through the placement of some sort of structure(s).

Rock Armour

Otherwise known as Riprap and Boulder Barriers, Rock armour consists of many large boulders piled up on top and next to each other, most commonly found on beach fronts and in areas of rough waves. These boulders are highly effective in the absorbing of the energy that comes from the waves. The main disadvantage associated with this method is the difficulty involved in transporting and placing masses of large, heavy boulders.

Sea Wall

A man made wall that has been built into the water, separating the sea from the land area is another method employed by construction workers and civil engineers, in aim to protect the coastline from the crashing water. These seal walls are especially effective in preventing coastal floods, as they leave no room for leakage. Although worthwhile, a seal wall is very difficult to build and will require maintenance as it will take some damage from waves and erosion over time.

Groynes

These can be simply described as wooden barriers that are built at right angles in relation to the beach. They are relatively simply to erect, and prevent the movement of beach materials along the coast by long shore drift and promote the healthy build-up of a beach – of which are natural guardians of the coastline (and of course excellent tourist attractions). These are highly effective in its use, however can be displeasing on the eyes and will need maintenance over its lifetime.

Soft management techniques are cheaper and usually more sustainable, but my not enjoy immediate success. Soft options include beach management – the replacement of sand that has been takes and compacted over time, along with the creation of managed retreats. This allows water to flow freely around its crashing point, but will often require the redevelopment of land by the coastline.


Jennings building and civil engineer contractors are geared up to help prevent erosion and damages to our beloved coastlines. With capability that will allow them to transport boulders for rock armour, they are an excellent choice when it comes to your planning and construction needs.

Image from 'ernohannink' license

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