Nature enriched structures and foreshores in freshwater environments
Low-lying delta areas often use dikes and other hard structures to protect the land against flooding, and harbour structures such as piers, docks and jetties for transport purposes. On top of their primary function, these structures are often used by a variety of plants and animals for growing, reproduction, nursery and feeding. Coastal defences can be improved in this respect by adapting traditional coastal engineering structures to this ecosystem function. This may even have a positive effect on the structure itself: extra dike stability and wave damping may be provided by deliberate introduction of vegetation such as saltmarsh, reeds, shrubs or trees. Eco-friendly revetments can contribute to the ecological value of a dike and – depending on their location and design, dikes may also host a range of other functions such as living, meadow-land and recreation. Several pilot experiments have been initiated along the Dutch coast. Also outside the Netherlands, projects for ecologically enriched seawalls are being developed. Based on the outcome of these experiments, the various designs are being improved continuously.
Here we consider the following types of structure enrichment:
Foreshores in freshwater environments: Replacing the traditional 'hard-cover' design, vegetated foreshores in freshwater environments have the ability to reduce wave impact, provide en enhance the natural value.
Rich revetments: This concept aims to create biodiverse habitats in the intertidal and subtidal zone of hard structures such as seawalls and harbours.