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 side of the lake, a hydroelectric dam sends water into the Hanefoss waterfall as it travels to Lake Herefossfjorden near the village of Herefoss. The lake is fed by the rivers Rettåna and Skjeggedalsåna.