Fish Upstream Passage through Gauging Stations: Experiences with Iberian Barbel in Flat-V Weirs

The monitoring of river discharge is vital for the correct management water resources. Flat-V gauging weirs are facilities used worldwide measuring discharge. These structures consist a small weir with triangular cross-section and flat “V”-shaped notch. Their extensive use consequence their utility in measurement both low high flow conditions. However, depending on size, local morphology can act as full or partial hydraulic barriers to fish migration. To address this concern, present work studies passage performance over flat-V considering performance. For this, radio-tracking video-monitoring observations were combined computational fluid dynamics (CFD) models two weirs, using Iberian barbel (Luciobarbus bocagei) target species. Results showed that conditioned by behavioral processes, providing evidence scenarios which may upstream movements. studied range 0.27–8 m3/s, drop difference between downstream levels lower than 0.7 m depth higher 0.3 be considered an effective situation barbels. findings interest quantifying impacts, engineering applications establishing managing retrofitting actions when required.