Dutch pilot results
The pilot project has been carried out by BAM and Rijswaterstaat (Dutch Department of Public Works) along the coast at Egmond aan Zee from November 2006 to Februari 2011. The coastline has been intensively monitored in order to perform a statistical analysis. Moreover, parallel to this monitoring campaign, a scientific investigation of the potential working mechanism has been carried out.
Results scientific investigation at Egmond aan Zee
Observations made during the scientific investigation have led to setting up a potential working mechanism of the Ecobeach system. A significant increase of the grain size has been measured at the southern Ecobeach test area. This effect has also been observed at a Danish test beach while performing a similar experiment. Furthermore, an indicator for vertical transportation of water through the drainage tubes has been observed at the low water line.
The probable working mechanism has been elaborated here.
Morphological results at Egmond aan Zee
The most important effects on the beach development during the test period at Egmond aan Zee have been observed by monitoring and measuring the coastline regularly. The test location is divided into two areas: test area north and test area south. See here de location of both test areas.
The sand volume of the beach at the southern test area (which is relatively less disturbed by nourishments) had increased to the highest ever measured volume since the start of the yearly measurements in 1964. It is quite remarkable that, within one and a half year after removing the system (early 2011), the sand volume had decreased to the same level as before the start of the experiment. The reference area south of the southern test area showed a similar figure. However, this area was affected by the beach nourishment at Heemskerk, south of the reference area, carried out in 2005.
The sand volume of the beach at the recently nourished northern test area stabilized during the test pilot. No net erosion of the nourished beaches was measured. Contrary to these measurements, clear observations of sand volume decrease were made after earlier nourishments. A new sand replenishment was then again inevitably required to recover the beaches.
Unfortunately, due to a newly scheduled sand replenishment right after removal of the system, it was not possible to observe the possible effects of removing the Ecobeach system on the northern test area.