Background and scope: Hydrological alteration by flow abstraction and subdaily flow fluctuation from hydropower is among the most significant pressures on river ecology in many countries. The Water Framework Directive (WFD) require sufficient flow regimes together with other measures for restore or rehabilitate the ecological conditions, by the best approximation to ecological continuum, if not exemptions from the objectives needs to be applied. Irreversible modification of hydromorphology (hymo) might lead to designation of water bodies as heavily modified, if e.g. restoration measures politically are considered to have significant adverse effect on e.g. hydropower or the wider environment. Still, some flow and ecological continuity is required to be in line with WFD, to ensure a sustainable management of river ecology.
Hydropower is considered to be an important and clean source of energy supply in many countries. However, to ensure sustainability of hydropower with regard to all relevant UN sustainability goals such as clean energy, climate and nature friendly, several ecological measures are relevant to mitigate negative impacts from hydropower development as much as possible. A common European mitigation library of relevant measure to be considered, have therefore recently been linked to WFD guidelines, as a basis for a common implementation strategy in guidelines (CIS no 4, no 31 and no 36[1]).
Hypothesis:
- The full potential of hydrological data for sustainable management by combining available data-sources, have not been utilized fully for assessing and classifying flow alteration in many countries according to WFD.
- Water and river flow management have huge user interests, and criteria for judging adverse effects and cost-efficiency of ecological flow is not sufficient transparent nor comparable, and thereby not fulfilling core principles of sustainable water management in several European countries.
- Hydrological modifications have not been managed in a comparable way, and there is a lack of common understanding of how this pressure should be managed in a consistent way.
R&D questions:
- What can be considered as emerging good and no-good management practice with regards to level of mitigation for common types of flow modifications?
- Are the same degree of alteration classified in a comparable way for type-specific rivers?
- What is the importance and characteristics of the following factors for Eflow levels?
- What is the dominating mitigation measures for rivers with modified flow?
Material and methods:
- International collaboration with flow alteration data from several rivers in Europe
- Hydrological indexes (modelled or monitored before/after hydropower development) from a number of rivers/countries will be assessed and compared to officially reported water body WFD data (pressure, ecological condition and objectives in WISE[1])
[1] https://www.eea.europa.eu/themes/water/european-waters/water-quality-and-water-assessment/water-assessments/ecological-status-of-surface-water-bodies
[1] http://ec.europa.eu/environment/water/water-framework/facts_figures/guidance_docs_en.htm
