Concept for an integrated ecological evaluation of running waters

This strategy paper presents a concept how to assess the ecological quality of running waters in the Federal Republic of Germany. The main cause for this paper is the original draft of an ecological guideline of the European Union (EU) which is going to become a part of a general frame guideline of the EU for waters. This guideline will ask of the European states a valuation of ecological quality of waters which is based on the undisturbed situation of the different aquatic ecosystems. The main basis for an ecological assessment is the classification of running waters in the Federal Republic of Germany according to their most important morphological and hydrological characteristics on one hand and a biocenotic description of these morphological/hydrological river types on the other hand. This method orientates itself by the natural type-specific reference status (leitbild) of streams and rivers. The main characteristics of running waters and their leitbilds may be combined in the major complexes biology morphology/hydrology, and chemistry. Each of these complexes can be investigated and assessed separately in a first step. In a following step, the single results may be summarized in an overall score of ecological quality. In this open assessment system (regarding the number of parameters) we propose 4 previous classes of ecological quality which may be extended later - if necessary - to 7 classes or more. Two variations of assessment are proposed. Variation 1 is thought for small to medium-sized streams and rivers. The assessment will be necessary in an extensive blanket coverage manner, and it should be done mainly biologically. Variation 2 will consider larger rivers with predominant chemical parameters because these are investigated in nearly ail these waters regularly and intensively.