Electric Fish Barrier Commissioned in Norway

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Smith-Root Staff
Thursday, October 09, 2014

Smith-Root commissioned the installation of an electric fish barrier in the tailrace of Rygenefossen (Rygene Hydro Powerplant) located near Arendal, Norway. The current structure at Rygenefossen initiated power production in 1978 after replacing a former power station at the same site.

The hydropower dam at Rygenefossen impounds the Nid River (Nidelva) and utilizes a hydraulic head of 38 feet. The on-site Kaplan turbine has a capacity of 56 MW and is fed by a 71-foot-long penstock. Water exits the turbine into a tunnel and travels two miles downstream before release back into Nidelva near the township, Helle.

In 2012, Agder Energi communicated with Dr Martin O’Farrell of Smith-Root Europe to discuss options for diverting anadromous fish species, including Atlantic salmon (Salmo salar) and Sea trout (Salmo trutta), away from the tunnel outlet (tailrace) during their annual upstream migration.

Principal Civil Engineer, Aaron Murphy, P.E., led a team of civil, water resource, and electrical engineers at Smith-Root, Inc., based in the USA, that designed an electric fish barrier to be installed during the Summer of 2014 to prevent entrainment and/or entrapment of critical fish populations at the hydropower facility.

This barrier represents Smith-Root’s fifth installation in Europe and second installation in Norway.