Less then 2 meters of dune left until the garden, which is lower, will be flooded with salty sea water. 
Vetiver for the stabilization and restoration of the sand dune.
The garden behind the rest of the formerly big sand dune is lower. Less than 2 meters and the garden will be flooded with salty water in winter storms.
The following slides are from a PDF that can be downloaded here from vetiver.org. It will be linked in a better place later and is just for demonstration for now. as
