Samenvatting

The in 2000 established Water Framework Directive urges Member states to realize and maintain chemically clean and ecologically healthy water systems by 2027. Water Board Scheldestromen manages the water system of Zeeland which consists of mainly brackish waters. These types of waters have a variety of stressors, including salt fluctuations and excess nutrients, making it difficult for species to survive. The Water Board implemented nature-friendly banks for increasing the natural value of the system, however a relatively low ecological value with a bank dominated by reeds and/or an absence of submerged water plants was observed in brackish waters. Water plants provide underwater structure for different species to use as hiding area, breeding area or attachment substrate and are therefore important for the natural value of the system . By analysing the components “Assessment WFD”, “Implementation”, Maintenance” and “Additional Measures” with the use of a survey, interviews and experiments a conclusion could be drawn on how to effectively maintain the natural value of nature-friendly banks in brackish waters. The “bad”
to “moderate” water quality is an highly influencing factor and requires cooperation on national scale for improvement. For Water Board Scheldestromen it is advised to focus on waterbodies with potential for increasing the water quality until 2027. For brackish waters with a relatively low water quality it is recommended to do a chemical and/or biological analyses to find the problem causing the lack of ecological value of the specific system. With the outcomes of the analyses suitable measures could be taken locally. Creating heterogeneity within a bank is also recommended. The established experiments which focused on creating under water structures could not be implemented within the research period. It is however recommended to implement the experiments to see the effectiveness of these measures.