Analysis of Cases on the Definition of Good Ecological Potential of Water Bodies Affected by Water Storage

In the latest Work Programme 2016-2018 of the Common Implementation Strategy (CIS) of the Water Framework Directive (WFD), the Water Directors of European countries agreed to set up a specific Ad-hoc Task Group (ATG) on best practice and guidance to deal with hydromorphology. In this context, one of the core activities of the Working Group (WG) ECOSTAT of the WFD CIS has been to compare the ecological quality expected by different countries for water bodies impacted by water storage.

In this context, an inter-comparison of national approaches for the definition of Good Ecological Potential (GEP) should be carried out. In early 2017, the GEP core group of ECOSTAT prepared a technical concept note on a case study inter-comparison of water bodies impacted by water storage. In addition, the ATG Hydromorphology co-chairs presented to ECOSTAT in April 2017 a discussion paper with more strategic considerations on the inter-comparison of GEP.

In an initial phase, the inter-comparison exercise is structured around "generic cases" of water storage situations. A questionnaire was developed to collect typical and good practice examples demonstrating national approaches for the definition of GEP in water bodies impacted by water storage. Ecologic Institute has been contracted by the Norwegian Environment Agency to provide support to the analysis of such examples provided by European countries in 2018.