Classification of state of water bodies in the Hurdalvassdraget/Vorma river basin district

Summary

Ecological state of 14 rivers and 2 lakes in the Hurdalvassdraget/Vorma river basin district, South-East Norway, has been classified in accordance with the Water Framework Directive. The classification is based on biological and physiochemical data, gained by field surveys in 2011, 2012 and 2014. Macro-invertebrates and benthic algae were applied as biological quality elements in rivers and creeks, while chlorophyll a and aquatic macrophytes were applied in the lake. The classification followed the ”one-out, all-out” principle, which means that the quality element with the poorest state determines the total classification result for the water body. The results show that most of the water bodies are in moderate or poorer ecological state. This means that there must be implemented measures in order to fulfil the environmental objective defined as good ecological state.