Skip to main content
Start of main content

Karahnjukar Hydroelectric Project

The highest concrete-faced rock-fill dam in Europe, and one of the highest in the world

  • 198

    Meter High

  • 4,600

    GWh Annually

  • Karahnjukar, Iceland

    Karahnjukar, Iceland

The largest power plant in Iceland

The 690 MW project provides an economical source of electric power for an aluminum smelter. The project includes: A 198-meter-high dam, one of the highest concrete-faced rock-fill dams in the world and the highest in Europe, a unique spillway with a 90-meter-long drop to a plunge pool in the canyon, 73 kilometers of hard-rock tunnels, 50 kilometers of high-voltage transmission line to the smelter (rated 420 kV but operated at 220 kV), and a 690 MW underground power station housing six 115 MW turbines at the world’s highest-head (600 meters) with a discharge of 144 m3/s and an annual generation of 4,600 GWh.

The joint venture completed the investigations and design, bid design and preparation of bid documents for competitive bidding for the project. Our team's principal role was the design of the dam and related components such as the diversion tunnels, bottom outlet, and the toe wall or canyon plinth supporting the concrete face of the dam. Staff also assisted with design of the headrace tunnels and provided technical support during construction and assistance with claims management. The project team successfully worked at the remote site under difficult and harsh cold weather conditions.

At a Glance



We're better together

  • Become a client

    Partner with us today to change how tomorrow looks. You’re exactly what’s needed to help us make it happen in your community.

    Contact Us
  • Design your career

    Work with passionate people who are experts in their field. Our teams love what they do and are driven by how their work makes an impact on the communities they serve.

    Join the Team
End of main content
To top