Building with Nature IJsselmeer (NAPRO) (KB-24-001-009, KB-14-004-048)

The proposed new water level management in Lake IJsselmeer has negative consequences for the valuable areas and nature reserves outside the dikes along the Frisian IJsselmeer coast, and for water safety for the area behind the dikes. The project ‘Zachte Zandmotor’ along the Frisian IJsselmeer coast investigates how a robust coastal defence can be achieved by utilizing natural processes. For this purpose underwater sand nourishment is applied at two pilot sites: Workumerwaard (sand bar constructed in 2011) and Oudemirdum (sand bar constructed in 2013). For a third location, Hindeloopen, a model study was executed. The main question of the project is whether sand nourishments (‘sand engine’) are a sustainable, cost-effective and ecologically resilient coastal reinforcement measure along the Frisian IJsselmeer coast. The function of a sand engine is based on the use of natural processes in the defence of the coast related to future water level rise and water level fluctuations. A monitoring program is currently executed to follow the effect of the sand engine on the coast, how and where the sand moves, and the effects on the vegetation under water and above water. This monitoring will continue until 2017. The knowledge gained in this project will be used to develop a strategy for sustainable protection and enhance the spatial quality of the entire Frisian IJsselmeer coast. This project is executed by a consortium consisting of Ecoshape, Alterra (part of Wageningen UR), Deltares, Arcadis, It Fryske Gea, Province of Friesland, Wetterskip Fryslân, Rijkswaterstaat, gemeente Súdwest-Fryslân, gemeente De Friese Meren and Stichting Het Blauwe Hart.