Project: illwerke vkw AG pumped storage hydropower plant “Obervermuntwerk II”
Location: Montafon, Vorarlberg, Austria
Cost: >10 million EUR
Dates: Implemented 2014-2018
Objectives: An existing hydropower plant was expanded with a new pumped storage hydropower facility with a capacity of 380 MW. Careful attention was paid during the design, the planning, and implementation phases to minimise the environmental impact and to integrate biodiversity measures wherever possible and appropriate.
Measures undertaken:
During site selection
Making the most out of existing infrastructures, the pumped storage power plant was conceived to utilize two reservoirs of an existing hydropower plant, thereby maximizing the energy-economic potential of the available water volumes, without the need to build a new dam. Thereby, avoiding the development of additional water extraction points and minimising the impact on water bodies.
During design, consenting and permitting
New habitats for the black grouse were created at a sufficient distance from the plant through targeted clearing and vegetation management. Relocation of an alpine moor away from the impact area. Disassembling an aboveground penstock and substituting it with an underground tunnel, restoring the habitats to natural conditions. Restoring impacted areas to natural conditions using only local materials to limit the introduction of non-native species, and using local seeds obtained from mowing nearby alpine grasslands
During construction
A comprehensive monitoring program was used to carefully check both the excavated material and the drainage water to detect deviations at an early stage and avoid any negative effects on the environmen
Results: The transplanted bog has adapted successfully to its new environment. The black grouse populations have remained stable in the face of construction activity, showing no significant changes, and have embraced the additional habitats created. The areas affected by the construction phase display few signs to distinguish them from the natural surroundings.
Challenges:
- Avoiding creating additional negative environmental impacts during dismantling of the penstock; and
- Additional flora which required protection was identified during project works, necessitating adaptive planning and additional consent with monitoring and documents for the EIA.
Success factors:
- A proactive approach to biodiversity integration;
- Comprehensive environmental monitoring;
- Utilization of locally available materials; and
- Restoration measures outside the actual project area.
Images copyright: illwerke
