To obtain a sustainable water catchment in the dune area, the IWVA and the Municipal Water Company of Knokke-Heist integrated drainage water and wastewater effluent in the existing potable water production process. The different types of raw water sources were all tested using a MF pilot plant from MEMCOR During the tests two alternative systems using UF membranes were compared to the MF performance. In a later stage of the tests the produced filtrate was used as the feed water for a RO pilot plant.