Sand nourishment – Sand bars Mirnserklif

Lessons Learned

  • From the fact that in four years’ time three out of the four sandbanks created by the nourishment had moved shorewards and the fourth one had disappeared we can learn that the water and sediment dynamics in the area determine whether or not such artificial sandbanks remain in place. At low-dynamic locations, the banks may create new habitats and only lose some sand to the immediate vicinity. In a more dynamic situation, the sediment can be spread over larger areas and a bank can disappear entirely.
  • The fact that two out of four sandbanks at the Mirnserklif still exist shows that in sheltered circumstances with a wide shallow zone artificial structures to maintain such banks are not needed. Yet, after a couple of years maintenance nourishments are needed in order to keep the sandbanks in shape and maintain their nature value.
  • Sand nourishments, like the one on Mirnserklif temporarily allow for a terrestrial habitat with pioneer vegetation on their top. In the longer run, they contribute to sedimentation in the coastal zone on local and regional scales and enable water,- marsh- and shoreline vegetation to develop.
  • These lessons have been taken into account in the design of the  Sand Engines – Friese IJsselmeer coast.