Hydropower is a relatively constant, weather-independent energy source, which can make a contribution to the energy transition towards renewable sources. The study shows that a large part of the hydropower potential available in North Rhine-Westphalia (NRW) is already being used. Additional potentials have been identified especially through expansion of existing hydropower plants. Taking legal requirements into account, scenarios relevant to aquatic ecology were developed, additional potentials identified and other aspects considered.

The Geul catchment area is one of the most important stream systems in the Netherlands. In order to be able to efficiently evaluate and approve the commissioning of hydropower plants, a practical decision making aid (evaluation model) was developed which includes the environmental requirements of the EU Water Framework Directive and of Natura 2000. This evaluation model can be used to assess other water systems and may be complemented with additional evaluation criteria.

The river Unstrut is one of the rivers for which the management plans for the German Federal State of Thuringia set the focus of the devised measures on restoring passability. Studies were carried out that covered not only the analysis of the individual barriers but also of their combined effect on passability and of the total disturbances caused by the reservoir and the original river bed sections. The analysis shows that the suggested passability restoring measures are able to create the conditions for the good ecological status for the fish fauna.

Regulation Effects of the German Renewable Energy Act on the Ecological Upgrade of Hydro-power Plants - Results of a Survey Germany lacks a unified register containing data on the equipment of hydropower stations with environmental facilities or of those subject to requirements for reducing the environmental impact on the status of Waters. Thanks to the cooperation of the hydro-power plant operators, our survey allowed us for the first time to gain insight into the regulation effects of the German Renewable Energy Act (Erneuerbare-Energien-Gesetz; EEG) as well as into the ecological upgrade potential of German hydro-power plants. EEG 2004 and 2009 funded measures implemented at hydro-power stations are focused on ensuring a minimum flow as well as on longitudinal Connectivity. This priority is consistent with the water management requirement of achieving the goals of the Water Framework Directive in this area.

The EU member states committed themselves to increasing the share of energy from renewable sources in the Ells final energy consumption from 10 to 20% by 2020. The electricity sector will provide an essential contribution in reaching this goal. Although the use of hydropower is already strongly developed in some European countries, a substantial additional potential is still available. Hydropower will play an important role in future electricity supply because of its base load and storage capacity.

The Federal Ministry of the Environment has commissioned a research project to determine the hydro power potential of Germany on the basis of an theoretical line potential approach. For this purpose current digital data of terrain morphology and flow rates have been processed and analyzed using a geographic information system (GIS). Considering the parameters of head utilization rate and machine efficiency, the line potential was further broken down to a technical hydro power potential. Results of this study show that 60% of the large water courses' theoretical hydro potential can be utilized. Of the small and mid-size water bodies about 20% of the line potential can realistically be utilized. Considering the current use of hydro power, the subtraction of the used potential and the unused technical potential results in a supplementary hydro power potential which is subject to further restrictions such as competing utilizations and legal requirements.

Deutschland hat sich zum Ziel gesetzt, 2030 einen Deckungsanteil der erneuerbaren Energien am gesamten Stromverbrauch von 45

On the basis ofthe information and assessment system QUIS, a strategic reconstruction concept with large-scale development targets for the reconstruction of longitudinal connectivity has been worked out. This includes planning objectives and measures for the diadromous and potamodromous priority watercourses in terms of a spatial and temporal prioritisation. This project has been undertaken in cooperation with the department of water management of the state of Rhineland-Palatinate.

Die durch das Bundesumweltministerium beauftragte Ermittlung des Wasserkraftpotenzials erfolgte auf der Grundlage des theoretischen Linienpotenzials. Dabei wurden digital vorliegende Daten zur Geländemorphologie und zu den Abflüssen in einem Geografischen Informationssystem (GIS) verarbeitet. Aus dem Linienpotenzial der deutschen Gewässer wurde mit Hilfe von Fallhöhennutzungsgrad und Anlagenwirkungsgrad das technische Wasserkraftpotenzial ermittelt. Die Studie zeigt, dass für große Gewässer maximal etwa 60

In Zusammenarbeit mit der Wasserwirtschaftsverwaltung des Landes Rheinland-Pfalz wurde auf der Grundlage des Informations- und Bewertungssystems QUIS ein strategisches Sanierungskonzept mit großräumigen Entwicklungszielen für die Wiederherstellung der Durchgängigkeit erarbeitet. Dieses umfasst Maßnahmen für diadrome und potamodrome Entwicklungsstrecken im Sinne einer räumlichen und zeitlichen Priorisierung.

Rhineland-Palatinate's Hydro Potential Rhineland-Palatinate has already developed a considerable por- tion of its hydropower potential. There still is, however, an un- tapped potential for medium and smaller hydro schemes; this potential is currently identified within the framework of a study entitled "assessment of Rhineland-Palatinate's migratory fish watercourses with a view to their passability and suitability for hydropower generation". The data base used for this study is the QUIS-RLP information system on transversal dam structures as of May 2006. In 2006, there were 175 hydropower plants with a total installed hydro capacity of 240 MW in Rhineland-Palat- inate. 200 MW were installed in 14 plants along the Mosel Riv- er and the Saar River with a capacity of � 1 MW. In addition, there are a considerable number of medium-sized and smaller plants. The annual amount of energy generated by existing plants was estimated to be 0.98 TWh. The untapped potential amounts to 0.03 TWh/a, of which some 0.01 TWh/a can prob- ably not be used for economic and ecological reasons.

Passability of Water Bodies in Rhineland Palatinate Tools for the Development of Plans of Measures According to the European Water Framework Directive, a lack of passability very often endangers the good ecological status and/or the good ecological potential of a water body. The great number of obstacles to fish migration and the considerable fi- nancial investment, which is needed for redesigning the water bodies, require a strategic concept that links the ecological rele- vance of individual sites with the wider development goals for potamod romous and diadromous fish populations. The water management administration of the Federal State of Rhineland Palatinate has developed an information and evaluation system that helps to identify priority areas and priority schedules for the planning of measures and supports and effective implemen- tation of those measures.