Integration of the Saprobic System into the European Union Water Framework Directive

Abstract

The use of saprobic systems has long traditions in the water management in Austria, the Czech Republic and Germany. Within the context of water quality assessment they are applied to indicate the effects of anthropogenic caused organic impact leading to a decrease in the dissolved oxygen content of running waters. In December 2000 the European Union Water Framework Directive (WFD) came into force. It demands homogeneous procedures and methods for assessing inland surface waters as well as groundwater, coastal and transitional waters. The WFD focuses on the assessment of biotic elements and the ecological status has to be defined based on type specific approaches and reference conditions. To incorporate the saprobic approach into the new integrative methodology of the European assessment of the ecological status of water bodies, the national saprobic systems need to be adjusted. This paper describes the according methodological developments and adaptations of Austria, the Czech Republic, and Germany required to harmonise the traditional procedure with the guidelines of the WFD. In the three countries national databases were established to provide species lists from largely undisturbed stream sites. Such reference sites build the basis for calculating stream type specific reference values. The calculation has been done in slightly different ways dependent on the country. In addition to that boundaries were defined to characterise the 5 saprobic quality classes.