Innovative design and refurbishment of the Lilla Edet scheme in Sweden

The Lilla Edet hydropower dam, inaugurated in 1926, is located north of Gothenburg along the river Göta älv, in Sweden. It was originally designed to supply power for the main railway line between Stockholm and Gothenburg. The need for dam safety improvements, including the capability of discharging a flood with a return period of 1:10000 years, prompted the partial reconstruction of the spillway dam. This paper describes the design decisions that have been taken regarding hydrology, hydraulic design, geological conditions, and the development of a low GHG with a reduced CO2 footprint, which does not require post-cooling.