On the southeastern end of the lake, there is a hydroelectric dam which releases water into the waterfall, Hanefoss, on its way down to the lake Herefossfjorden near the village of Herefoss. The lake is fed by the rivers Rettåna and Skjeggedalsåna.
On the southeastern part of the lake, there is a hydroelectric dam that pours water into the waterfall, Hanefoss, as it flows down to the lake Herefossfjorden near the village of Herefoss. The lake receives its water from the rivers Rettåna and Skjeggedalsåna.