Among the highest points of the headwaters are the lake Steinurdalstjern which sits at an elevation of 1,429 metres (4,688 ft) above sea level.

[2] There are several places along the river which have been dammed and these have formed a number of large lakes including Vangsmjøse, Slidrefjorden, Strondafjorden, and Aurdalsfjorden.

Over the years the river has been developed for hydroelectric power with a maximum output of approximately 326 megawatts (437,000 hp) (as of 2003) including on its tributaries.

Its purpose is to protect members' common interests with regard to the use of water from the Begna river basin that is used for power generation.

The hydropower company operates 20 power plants on the Begna (and the river Drammenselva which flows from the lake Tyrifjorden to the sea.