Author(s): Markus Foerst; Atle Harby

Linked Author(s): Markus Foerst, Atle Harby, Markus Peter Först

Keywords: Ecohydraulics; Hydrology; Habitat; Pumped storage hydropower

Abstract: The growing share of wind and solar power increases the need for flexible hydropower and energy storage. Pumped-storage hydropower can address these challenges by enhancing operational flexibility and storing surplus energy. This study evaluates the feasibility of upgrading the Nedre Driva hydropower system by pumping water to an expanded Gjevilvatnet reservoir and constructing a new high-capacity station discharging into the fjord. Habitat mapping shows that the river has very good mesohabitat conditions for salmon, but a bottleneck occurs at flows below 5 m³/s. Hydrological analysis of historical discharge data combined with habitat mapping indicates that maintaining summer flows of approximately 20 m³/s and winter flows of at least

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.269

Year: 2026