Diffusion of a mega feeder nourishment: Assessing 5 years of Sand Engine spreading

Feeder nourishments, where sand quantities of O (10 million m³) are placed locally to feed adjacent coastal stretches, are suggested nowadays as an alternative for local, smaller-scale nourishments (< 1 million m³). These feeder nourishments rely on natural forces to spread the sediment. While processes that govern this spreading such as tidal flows, waves and wind are well known, the quantification of associated sediment transport processes remains a scientific challenge. Due to the lack of knowledge with respect to sediment spreading, no tools exist to optimize the design of feeder nourishments. The Sand Engine project that is implemented in the Netherlands in 2011 consists of 21.5 million m³ of nourished sediment, and is the largest existing feeder nourishment (Stive et al., 2013). In this paper the morphological development of the Sand Engine mega feeder nourishment and the adjacent coastal sections is presented. The alongshore extent of the analysis is 17 km and spans a coastal cell between 2 harbor entrances.Coastal Engineerin