Overview of typical compensation measures and results of the monitoring campaign on the Upper Rhine at two HPPs / FIThydro, Augsburg / Jochen Ulrich
Overview Upper Rhine HPP Rheinfelden and Ryburg-Schwörstadt (Average discharge Upper Rhine: 1030 m³/s) HPP Ryburg-Schwörstadt HPP Rheinfelden Basel Lake Constance 2
Overview Upper Rhine HPP Ryburg-Schwörstadt (max. 1460 m³/s, 120 MW, production: 760 Mio. kwh/a) 3
In total 17 compensation measures (to get new approval / no technical changes at the HPP) 4 12.08.2014 B. Karrer
Overview Upper Rhine HPP Rheinfelden (max. 1500 m³/s, 100 MW, production: 600 Mio. kwh/a) 5
Former HPP Rheinfelden Construction: 1894-1898 biggest river power plant at that time // Main changes and impacts of new HPP Higher Water level +1,4m -> changes in hydraulics and ground water Loss of rock formation and habitat 6
Rheinfelden hydro power projekt Overview after construction / Overview fishways In total more than 80 compensation measures Roughened fischway Near-nature water course Vertical-Slot fishway 7
Overview compensation measures Examples will be shown in the presentation Fish passage (technical or near-nature fishways) Residual flow / Minimum flow Reconnecting oxbows, flood plains and small tributaries Renaturation Structural diversity of the shore and the river bed Specific measures to the protection of species Ground water Cultural Heritage Landscape / Recreation 8
Fish passage / Minimum flow / Habitat structures Ecological functions of the near-nature water course / Separate turbine for minimum flow purposes Separate turbine 30m³/s to ensure minimum flow on the rocks (to save spezialised species of moss ) (positive results in the last monitoring period!) Ecological functions: Riffles built out of gravel (spawning ground for common nase and barbel) Pools with gravel banks (habitat for different species) Deeper flow path (to ensure fish passage) Ecologically effective habitat structures (Gravel islands, rootstocks, trees, ) 9
Fish passage HPP Ryburg-Schwörstadt Two entrances with connection to the river bed and attraction flow 300 kw turbine / electricity + attraction flow 3D Graphic- Tailrace HPP Ryburg-Schwörstadt The attraction flow is generated by the discharge of a separately built 300 kw - turbine 10
HPP Rheinfelden Results of fish counting Fish passage Upper Rhine 2005-2006 compared with the results of the 2012-2013 and 2016-2017 fish countings in Rheinfelden 2016-2017 Quelle: Guthruf 2017 Quelle: Aquarius 2013 11
Comparison of the results of the Rheinfelden 2012-2013 fish counting with the counting 2005/2006 Upper Rhine, total number of species 12 The counting 2016-2017 showed almost the same results like the 2012-2013-counting Quelle: Aquarius 2013
Results fish counting Length of the registered fish (logarithmic diagram) Quelle: Aquarius 2013 13
Comparision of the migrating species in the two fishways (left: water course, right: vertical slot) Near-nature water course: 34 species Vertical slot: 24 species Different abundance of species Quelle: Aquarius 2013 14
Fish passage HPP Rheinfelden Fish counting - summary High number of migrating fish Very high number of species Abundance of rare species has significantly grown No selectivity Target species are present Similar results at the HPP Ryburg-Schwörstadt 15
Structural diversity of the shore and the river bed Gravel deposits / 1500 m³ every two years 16
Structural diversity on the shore and in the river bed 17 Quelle: Aquarius 2018
Structural diversity of the shore and the river bed Gravel deposits Objectives: Spawning ground, reactivation of sediment transportation Results monitoring: More gravel on the river banks and the river bed: But only few greylings in the initial feeding stage Spawning ground only in small quantities, gravel is eroded within short time Optimization of the measures: Find a better site Coordination on the whole Upper Rhine 18
Structural diversity of the shore and the river bed Artificial erosion of river banks 19 Quelle: Aquarius 2018
Structural diversity of the shore and the river bed Artificial erosion of river banks Objectives: Structure, small bays, trees as habitat Results monitoring: Small scale gravel deposits Greylings an barbels Optimization of the measures : none From time to time: remove vegetation 20
Reconnecting flood plain (Aue Wallbach) 21 Quelle: Aquarius 2018
Reconnecting flood plain (Aue Wallbach) Objectives: Dynamic, Structure, new oxbow, more habitats and retreat areas for juveniles and small species Results of monitoring: Sedimentation in the upper part, no more oxbow, but now backwater High fish density and many species high improvement Valuable retreat area and habitat for juveniles and small species Optimization of the measures: Backwater very valuable no measure to ensure reactivation of oxbo If sedimentation goes on take some measures to ensure the backwater habitat. 22
HPP Rheinfelden Monitoring vegetation 2013: Succession area 2016: More vegetation on the Succession areas Quelle: Ruess 2017 23
HPP Rheinfelden Monitoring vegetation Results total species total species: 2010: 251 2013: 318 2016: 335 Highest level in succession areas and meadows Quelle: Ruess 2017 24
HPP Rheinfelden Monitoring vegetation Results total number of endangered species (CH) Endangered species (CH): 2010: 14 2013: 28 2016: 30 Highest level in succession areas and meadows Quelle: Ruess 2017 25
Results landscape slightly improved in the whole perimeter Low quality High quality Low quality Medium quality Quelle: Ruess 2017 26
Results landscape slightly improved in the whole perimeter But also some places with lower quality Low quality High quality Quelle: Ruess 2017 27
Monitoring HPP Rheinfelden Birds Goosander family close to the rock formation Great Crested Greep is breeding at the intake of the near-nature water course Quelle: Ruess 2018 28
Monitoring HPP Rheinfelden Birds Artificial erosion sites are breeding places for the kingfisher 29
Compensation measures at HPP Rheinfelden and HPP Ryburg-Schwörstadt Summary The results in upstream migration, vegetation and landscape are very good. Most of the results in fauna are good as well, some of the measures probably take some time to reach full ecological function. Most of the measures to improve the structural diversity of the shore and the river bed are very successful: i.e. artificial erosion, trees, oxbows/backwater. High fish density in these places. Finding the right place for gravel deposits that result in spawning grounds for greylings seems to be difficult. Overall the compensation measures at the HPP Rheinfelden and Ryburg- Schwörstadt are very successful and improve the habitat of terrestrical and aquatic species significantly. 30