Hydropower research projects

Achieving sustainable operation of hydropower plants requires a sound understanding of the dynamic processes in flowing bodies of water. One management challenge and an important point for the river as an ecosystem is the transport of sediments.

The CD Laboratory researches the principles of erosion and sedimentation and analyses the transport and remobilisation of solids. Through optimised sediment management, ecological, economic and technical solutions can be elaborated, flood protection ensured and acceptance in society increased.

A better understanding of the process is acquired in a combination of laboratory trials and investigations in the field. The dimensions considered extend from the μm range to entire river catchment areas.

The findings obtained serve as a basis for the development of new monitoring and modelling technologies and for the creation of new standards for the use of hydropower. They additionally support the development of sustainable management concepts in riverscapes.

Badura, H., Knoblauch, H., Schneider, J., Harreiter, H., & Demel, S. (2007). Wasserwirtschaftliche Optimierung der Stauraumspülungen an der oberen Mur. Österreichische Wasser- und Abfallwirtschaft, 5(59), 61-68.

Link to the abstract: Wasserwirtschaftliche Optimierung der Stauraumspülungen an der Oberen Mur | SpringerLink
Häckl, C., Klocke, R., Straßer, K. H., Loy, G., & Reckendorfer, W. (2022). Workshop zum Sedimentmanagement an Stauanlagen an großen Gewässern im Donaueinzugsgebiet. Wasserwirtschaft, 112(6), 52-55.

Link to the abstract: Workshop zum Sedimentmanagement an Stauanlagen an großen Gewässern im Donaueinzugsgebiet | springerprofessional.de
Hauer, C., Haimann, M., Holzapfel, P., Flödl, P., Wagner, B., Hubmann, M., ... & Schletterer, M. (2020). Controlled Reservoir Drawdown—Challenges for Sediment Management and Integrative Monitoring: An Austrian Case Study—Part A: Reach Scale. Water, 12(4), 1058.

Link to the full text: Water | Free Full-Text | Controlled Reservoir Drawdown—Challenges for Sediment Management and Integrative Monitoring: An Austrian Case Study—Part A: Reach Scale (mdpi.com)
Hauer, C., Holzapfel, P., Flödl, P., Wagner, B., Graf, W., Leitner, P., ... & Schletterer, M. (2020). Controlled reservoir drawdown—Challenges for sediment management and integrative monitoring: An Austrian case study—Part B: Local Scale. Water, 12(4), 1055.

Link to the full text: Water | Free Full-Text | Controlled Reservoir Drawdown—Challenges for Sediment Management and Integrative Monitoring: An Austrian Case Study—Part B: Local Scale (mdpi.com)
Loy , G. (2022). Sedimentmanagement in Staustufenketten - Notwendigkeit, Herausforderungen und Umsetzungsbeispiele. WASSERWIRTSCHAFT, volume 112, issue 2-3, 45-50.

Link to the full text: WaWi2/2022 | WaWi e-journal (springerprofessional.de)
Mühlbauer, M., Lauber, W., Derntl, F., Ratschan, C., Schmalfuß, R., & Zauner, G. (2023). Dynamische Dotation und Sedimentmanagement zur Gewährleistung funktioneller Fließgewässerhabitate in Fischwanderhilfen. Österreichische Wasser- und Abfallwirtschaft, 75(1), 73-86.

Link to the abstract: Dynamische Dotation und Sedimentmanagement zur Gewährleistung funktioneller Fließgewässerhabitate in Fischwanderhilfen | SpringerLink
Reckendorfer, W. (2022). Sedimentmanagement in Stauketten-Ökologische Ziele und Herausforderungen. WASSERWIRTSCHAFT, volume 112, issue 2-3, 57-60.

Link to the full text: WaWi2/2022 | WaWi e-journal (springerprofessional.de)
Reckendorfer, W., Badura, H., & Schütz, C. (2019). Drawdown flushing in a chain of reservoirs—Effects on grayling populations and implications for sediment management. Ecology and Evolution, 9(3), 1437-1451.

Link to the full text: Drawdown flushing in a chain of reservoirs—Effects on grayling populations and implications for sediment management - Reckendorfer -2019 - Ecology and Evolution - Wiley Online Library
Reckendorfer, W., Ogertschnig, K., Grüner, B., & Zornig, H. (2024). Kontrollierte Stauraumabsenkungen hatten keine nachweisbaren Auswirkungen auf die Fischpopulationen der Möll–ein Kommentar zu Pinter et al.(2024). Österreichische Wasser-und Abfallwirtschaft, 1-12.

Link to the full text: Kontrollierte Stauraumabsenkungen hatten keinenachweisbaren Auswirkungen auf die Fischpopulationender Möll – ein Kommentar zu Pinter et al.
Schmalfuß, R. (2022). Sedimentmanagement bei Stauanlagen: Herausforderungen und Lösungen. WASSERWIRTSCHAFT, volume 112, issue 2-3, 65-68.

Link to the full text: WaWi2/2022 | WaWi e-journal (springerprofessional.de)

The research project investigates the impacts of surge and residual water loads on aquatic life. The possibility of alleviating these loads through ecological measures was investigated and evaluated along selected pilot sections.

At the same time, the energy industry and system-relevant restrictions that can arise during the implementation of ecological measures are assessed. The project also elaborates scientific principles on the possibilities and impacts of an improved residual water discharge, especially in the high mountains. The research work will continue for a period of six years. The long project duration is mainly due to the necessary field work in the high alpine habitat. This is carried out in influenced waters and reference waters. In addition, dotation trials at representative trial sites will be started. Building on this, an ecological evaluation and monitoring system will be developed by the end of the project term.

The basis for the current research project ÖkoResch was the project “Sustainable River Management – Energy and environmental evaluation of possible surge-damping measures”, with the two modules “SuREmMa” and “SuREmMa+”. For the first time, these projects created the basis for an Austria-wide, standardised evaluation tool for surge remediation measures.

In a first step, an economic and ecological evaluation system for surge-damping measures, such as operation restrictions, surge damping ponds, surge discharge power plants and morphological remediation measures, was developed. From an economic perspective, restrictions on the use of storage power plants result directly in balancing energy having to be provided for grid stabilisation through fossil energy sources or nuclear energy in the event of the absence of volatile forms of energy such as wind and solar. The water ecological effectiveness of the measures was compared with these economic and operating effects and evaluated. The evaluation toolset was representatively tested at ten Austrian storage power plants.

In SuREmMa+, the measures evaluation was refined, a monitoring concept matched to the evaluation methods was developed and applied to selected case studies. The evaluation encompasses the stranding and drifting of aquatic organisms (fish, macrozoobenthos), the availability and quality of habitat as well as an estimate of the economic impacts.

Using the elaborated evaluation criteria, it is possible to put in place targeted measures for certain sections of waterway in order to achieve a good aquatic-ecological condition or potential under consideration of ecological and energy industry impacts.

Greimel, F., Grün, B., Hayes, D. S., Höller, N., Haider, J., Zeiringer, B., ... & Schmutz, S. (2023). PeakTrace: Routing of hydropeaking waves using multiple hydrographs—A novel approach. River Research and Applications, 39(3), 326-339. 

Link to full text: PeakTrace: Routing of hydropeaking waves using multiple hydrographs—A novel approach - Greimel - 2023 - River Research and Applications - Wiley Online Library
Greimel, F., Neubarth, J., Fuhrmann, M., Führer, S., Habersack, H., Haslauer, M., ... & Zeiringer, B. (2017). SuREmMa-Sustainable River Management-Energiewirtschaftliche und umweltrelevante Bewertung möglicher schwalldämpfender Maßnahmen. Forschungsbericht, Wien. 

Link to report: SuREmMa – Forschungsbericht (bml.gv.at)
Greimel, F., Neubarth, J., Fuhrmann, M., Zoltan, L., Zeiringer, B., Schülting, L., & Schmutz, S. (2021). SuREmMa+: Entwicklung einer Methode zur ökologischen und energiewirtschaftlichen Bewertung von Maßnahmen zur Minderung von negativen schwall-und sunkbedingten ökologischen Auswirkungen. Forschungsbericht, Wien. 

Link to report: SuREmMa+ - Forschungsbericht (bml.gv.at)
Schmutz, S., Fohler, N., Friedrich, T., Fuhrmann, M., Graf, W., Greimel, F., ... & Zeiringer, B. (2013). Schwallproblematik an Österreichs Fließgewässern–Ökologische Folgen und Sanierungsmöglichkeiten. BMFLUW, Wien, 176. 

Link to report: Schwallproblematik an Österreichs Fließgewässern – Ökologische Folgen und Sanierungsmöglichkeiten (bml.gv.at)

For many years now, projects to improve habitat and species diversity in aquatic habitats have been carried out on the Danube. However, little is known about the cumulative added value of the individual projects and their spillover effects. The CD Laboratory MERI, under the professional direction of the University of Natural Resources and Life Sciences, deals with these questions.

To better understand the dynamic processes occurring in the Danube, the meta-ecosystem approach combines biological processes, human activities and ecosystem services on different spatial and temporal scales. Thus, for example, migration behaviour and the habitat selection of fish are investigated to identify habitat preferences and deficits. Food web relationships in different sections of river are also analysed, as are the ecosystem performance of the river landscape and the way in which fishing impacts the river. The findings obtained should in future be used to develop strategies for even more purposeful ecological measures and facilitate the taking of targeted management decisions.

Initial results show that the newly created habitats on the Traisen or Grosse Tulln are accepted by Danube fish to a large extent as spawning habitats. The large bypass rivers created on the Danube within the scope of LIFE (LIFE-NETZWERK-DONAU.AT) even enable fish from the Freudenau reservoir to spawn in the newly created underflow of the Traisen (LIFE-TRAISEN.AT).

Passive Integrated Transponder (PIT) tag technology is in used on a large scale in several research projects in Austria and Bavaria. It is particularly good at recording the migration behaviour of fish over a longer period of time and reconstructing their movement patterns.

It enables the investigation of passability, findability and use of fish passes as a means of descent, as well as the temporal and spatial progression of the migrations, the distribution of the fish and the use of habitat. The objective of the investigations is to improve understanding of the habitat requirements of fish fauna and in particular to investigate pan-regional questions of migration behaviour and habitat selection. In this way, it should be possible to better assess the effectiveness of aquatic ecological measures in the future. These findings can subsequently be used for the further development of previously implemented land restoration measures and fish passes.

PIT tags are passive transponders used for the electronic marking of fish. When marked fish swim past an antenna installed in the river or in a fish pass, they are registered and identified. With the aid of recordings made in a waterway system with many antennae, the migration behaviour of both individual fish and entire populations can be traced. The project area being worked on by VERBUND extends from the power plant at Freudenau near Vienna along the Danube as far as the Inn in Bavaria.

Initial investigations are revealing some surprising results. For example, it was discovered that shipping locks are used by fish to a not inconsiderable extent for migration purposes. They also showed that the fish - in contrast to prevailing opinion - also use the fish passes to migrate downstream. It was also confirmed that several species exhibit a distinct sense of homing, i.e. they return to the same stretch of water every year to spawn.

Measures to protect the fish populations in waterways characterised by hydropower have so far concentrated almost entirely on longitudinal consistency for fish. These measures are mainly aimed at fish that migrate over medium and long distances. Fish that migrate of short distances in particular can probably benefit much more from habitat-improving measures in waterways and their wetlands than from the pure restoration of consistency.

In order to better understand the importance of individual measures and their interconnectedness for the fish populations in the Inn, a research concept was initially elaborated within the scope of preliminary investigations in 2013-2015.

Building on those, practical field studies have been carried out by the Technical University of Munich since 2015. The main project is set up for a period of ten years and arranged into three project sections investigating measures in the side and still waters of the Innaue wetlands (Part I), bank widening and hydrological structures in the Inn main channel (Part II) and the interconnecting of the various partial habitats (Part III). Results obtained so far clearly show that the near-natural bypass rivers represent an important habitat for fish and benthic invertebrates and function as a source of biodiversity for the main channel.

Since 2018, the research project has dealt with a range of open questions on what triggers fish migrations and how fish orientate themselves in waterways. Current opinion assumes that fish primarily orientate themselves in response to hydraulic stimuli. Other external factors such as light, acoustic stimuli, oxygen content or temperature are largely ignored. Field investigations creating a link between the ascent behaviour of migrating fish and the various key stimuli in a high temporal resolution have so far been lacking.

The four stimuli of acoustics, light, water temperature and flow are investigated within the scope of the project. Thermal stimuli, acoustic stimuli and light stimuli are generated in situ at the entrance to the fish pass. To measure the flow and temperature conditions, drone-supported, high-resolution optical cameras and thermal imaging cameras are used. The flow is measured contactlessly using optical methods such as Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV). This involves photographing particles in the water at short time intervals. The direction and velocity of movement can be determined from the positions of the particles. Moreover, existing software tools are trialled, further developed and then adapted and optimised to the questions at hand.

Results obtained to date indicate that of the parameters investigated, only the temperature plays a role in triggering fish migration and the way in which fish orientate themselves. No effect of acoustic stimuli, flow and light could be established. These results also call into question the currently prevailing paradigm that river fish need a distinct “lure current” in order to find the entrance to fish passes.

Bondar-Kunze, E., Funk, A., Haidvogl, G., Unfer, G., Muhar, S., Hohensinner, S., ... & Hein, T. (2022). Der Meta-Ökosystem Ansatz in der Praxis–Integration von hydromorphologischen Veränderungen und menschlichen Eingriffen in die Meta-Ökosystem-Theorie zur Entwicklung eines nachhaltigen Flussmanagements an der österreichischen Donau. Österreichische Wasser-und Abfallwirtschaft, 1-9.

Link to the full text: Der Meta-Ökosystem Ansatz in der Praxis – Integration von hydromorphologischen Veränderungen und menschlichen Eingriffen in die Meta-Ökosystem-Theorie zur Entwicklung eines nachhaltigen Flussmanagements an der österreichischen Donau | Springer-Link
Brandl, A., Käfer, S., Fillitz, B., Pinter, G., Laaha, G., & Mader, H. (2020). Relevance of key stimuli, in particular light and acoustics, for the findability of fish passes. Österreichische Wasser-und Abfallwirtschaft, 72, 187-201.

Link to the full text: Relevance of key stimuli, in particular light and acoustics, for the findability of fish passes | SpringerLink
Brandl, A., Käfer, S., Laaha, G., & Mader, H. (2022). Temperatur Als Schlüsselreiz Für Die Auffindbarkeit von Fischaufstiegsanlagen. Wasserwirtschaft, 12-18.

Link to the abstract: Temperatur als Schlüsselreiz für die Auffindbarkeit von Fischaufstiegsanlagen | springerprofessional.de
Brandl, A., Laaha, G., Käfer, S., & Mader, H. (2022). Key Factors for the Findability of Fish Passes in Large Epipotamal Rivers: The Case of the River Drava. Water, 14(10), 1530.

Link to the full text: Water | Free Full-Text | Key Factors for the Findability of Fish Passes in Large Epipotamal Rivers: The Case of the River Drava mdpi.com
Käfer, S. (2019). Verbesserung der ökonomischen Effizienz bei gleichbleibender ökologischer Effektivität. WASSERWIRTSCHAFT, 109(10), 45-47.

Link to the full text: WaWi 10/2019 | WaWi emagazine (springerprofessional.de)
Kaufmann, T., Frik, G., Schmalfuß, R., Haidvogl, G., Eberstaller, J., Wimmer, H., Jungwirth M. (2018). LIFE+ Traisen: Der lange Weg zum neuen Fluss. Österreichische Wasser-und Abfallwirtschaft, 70 (5-6), 264-271.

Link to the full text: LIFE+ Traisen: Der lange Weg zum neuen Fluss | Springer-Link
Loy, G., & Reckendorfer, W. (2022). Creation and Use of “Compensation” Habitats—An Integrated Approach. In Novel Developments for Sustainable Hydropower, 157-165. Cham: Springer International Publishing.

Link to the full text: Creation and Use of “Compensation” Habitats—An Integrated Approach | SpringerLink
Nagel, C., Mizerakis, V., Pander, J., & Geist, J. (2022). The overlooked contribution of a fish bypass channel to the density and diversity of macroinvertebrate drift in a heavily modified river system. River Research and Applications, 38(10), 1696-1707.

Link to the full text: The overlooked contribution of a fish bypass channel to the density and diversity of macroinvertebrate drift in a heavily modified river system - Nagel -2022 - River Research and Applications - Wiley Online Library
Nagel, C., Mueller, M., Pander, J., & Geist, J. (2020). Making up the bed: Gravel cleaning as a contribution to nase (Chondrostoma nasus L.) spawning and recruitment success. Aquatic Conservation: Marine and Freshwater Ecosystems, 30(12), 2269-2283.

Link to the full text: Making up the bed: Gravel cleaning as a contribution to nase (Chondrostoma nasus L.) spawning and recruitment success (tum.de)
Nagel, C., Mueller, M., Pander, J., Stoeckle, B. C., Kuehn, R., & Geist, J. (2021). Going with the flow: Spatio‐temporal drift patterns of larval fish in a large alpine river. Freshwater Biology, 66(9), 1765-1781.

Link to the full text: Going with the flow: Spatio‐temporal drift patterns of larval fish in a large alpine river - Nagel - 2021 - Freshwater Biology - Wiley Online Library
Nagel, C., Pander, J., Mueller, M., & Geist, J. (2020). Substrate composition determines emergence success and development of European nase larvae (Chondrostoma nasus L.). Ecology of Freshwater Fish, 29(1), 121-131.

Link to the full text: Substrate composition determines emergence success and development of European nase larvae (Chondrostoma nasus L.) - Nagel - 2020 - Ecology of Freshwater Fish - Wiley Online Library
Oberlerchner, D. (2018). LIFE Netzwerk Donau Umsetzung ökologischer Projekte im Spannungsfeld von Kosten und Schutzwasserwirtschaft. Wasserbausymposium 2018 Wasserwirtschaft Innovation aus Tradition, 147-152.

Link to the book: Wasserbausymposium Graz 2018 - Verlag der TU Graz (tugraz-verlag.at)
Pander, J., Nagel, C., Ingermann, H., & Geist, J. (2022). Water level induced changes of habitat quality determine fish community composition in restored and modified riverbanks of a large alpine river. International Review of Hydrobiology, 107(1-2), 46-59.

Link to the full text: Water level induced changes of habitat quality determine fish community composition in restored and modified river banks of a large alpine river - Pander -2022 - International Review of Hydrobiology - Wiley Online Library
Perks, M. T., Dal Sasso, S. F., Hauet, A., Jamieson, E., Le Coz, J., Pearce, S., ... & Manfreda, S. (2020). Towards harmonisation of image velocimetry techniques for river surface velocity observations. Earth System Science Data, 12(3), 1545-1559.

Link to the full text: ESSD - Towards harmonisation of image velocimetry techniques for river surface velocity observations (copernicus.org)
Reckendorfer, W., Schabuss, M., & Petz-Glechner R. (2023). Abwärtswanderung durch eine Fischaufstiegsanlage - neue Erkenntnisse durch Untersuchungen mittels PIT-Tags. WASSERWIRTSCHAFT 113,31 - 34.

Link to the abstract: Abwärtswanderung durch eine Fischaufstiegsanlage - neue Erkenntnisse durch Untersuchungen mittels PIT-Tags | springerprofessional.de
Reckendorfer, W., Zornig H., Schabuss, M., & Petz-Glechner, R. (2023). Effekte der Dotation auf die Auffindbarkeit von Fischwanderhilfen – Ergebnisse von PIT Tag Untersuchungen an der Donau. Wasserbausymposium Wallgau.

Strelnikova, D., Paulus, G., Käfer, S., Anders, K. H., Mayr, P., Mader, H., ... & Schneeberger, R. (2020). Drone-based optical measurements of heterogeneous surface velocity fields around fish passages at hydropower dams. Remote Sensing, 12(3), 384.

Link to full text: Remote Sensing | Free Full-Text | Drone-Based Optical Measurements of Heterogeneous Surface Velocity Fields around Fish Passages at Hydropower Dams (mdpi.com)
Strelnikova, D., Paulus, G., Käfer, S., Anders, K. H., Mayr, P., Mader, H., ... & Schneeberger, R. (2020). Drohnenbasierte optische Ermittlung von heterogenen Oberflächenströmungsmustern in der Nähe von Fischaufstiegshilfen/Drone-based Optical Detection of Heterogeneous Surface Flow Patterns in the Vicinity of Fish Ladders. AGIT Journal Angew. Geoinformatik, 6, 206-216.

Link to the full text: Microsoft Word - 404_Strelnikova_Am_go_final.docx (gispoint.de)
Strelnikova, D., Perks, M. T., Paulus, G., Käfer, S., Anders, K. H., Mayr, P., ... & Schneeberger, R. (2022). Rapid Detection of the Change in Surface Flow Patterns Near Fish Passages at Hydropower Dams With the Use of UAS Based Videos Under Controlled Discharge Conditions. Frontiers in Remote Sensing, 3, 14.

Link to the full text: Frontiers | Rapid Detection of the Change in Surface Flow Patterns Near Fish Passages at Hydropower Dams With the Use of UAS Based Videos Under Controlled Discharge Conditions (frontiersin.org)