Grytten power plant

The plant draws water from Mardalsfossen, one of Norway's highest and most famous waterfalls. The power plant also draws operating water from the following lakes: Olaskarsvatnet, Fetjavatnet, Mongevatnet via Monge pumping station, Grøttavatnet, Rangåvatnet and Nedre Mardalsvatnet via Mardal pumping station, and Fossafjelltjønna.

With the use of technical systems and pumping arrangements, Mardalsfossen maintains a minimum water flow of between 2.0 and 2.5 cubic metres per second during parts of the summer season.

The main intake reservoir Lake Grøttavatnet is regulated between 979.9 and 930 metres above sea level.

Part of the catchment area of the power plant is located in Nesset Municipality. Water is also transferred from the Eikesdals watercourse. This water, along with the remaining water from the power plant, is discharged into the Rauma River.

The gross height of fall to the power plant is 964 metres.