Globally, it is widely acknowledged that constructing hard engineered coastal defences is both financially and environmentally unsustainable.
Hard engineered structures such as seawalls, groynes and breakwaters are often built to reduce coastal erosion and maintain a minimum beach width for recreation along coast regions.
New Zealand, unlike many other countries, has continued to rely on reforestation (a soft measure) to control erosion rather than use a mix of soft and hard (engineered) approaches that are common in developed countries to control erosion.
Population density and infrastructure in many of these countries requires a higher level of protection than rural land in New Zealand and is the primary reason why hard engineered approaches in combination with vegetation are favoured.
A shift from 'coastal armoring' and hard engineered 'defense systems', to ecologically informed infrastructures has created opportunities and challenges in designing structures that can perform beyond engineering goals and provide ecological and social benefits.
Along coasts with hard engineered protection constructed to defend against erosion, the presence of three to six metre high concrete-faced embankments results in severe erosion on their landward faces.
Acting on the perception that they perform better for longer, most property owners in the United States choose hard engineered structures, such as bulkheads or riprap revetments, to protect estuarine shorelines from erosion.
Reasons for the apparent decline in France are uncertain but could include: loss of knowledge about bioengineering techniques, difficulty in deciding which technique to use where, and a general lack of trust in the efficacy of vegetative methods compared to "hard" engineered control measures.
Widely varying predictions about climate change make it especially hard for engineers to build for the future — or for insurers to guard against weather-related losses.
"The winds have also caused structural damage and closed many roads, making it hard for engineers to access faults.
