Minimum flow is an important mitigation measure for the natural environment, particularly for vegetation and fish, but also for the public’s experience of the landscape. In Hjartdøla river, a release of 1,000 l/s* in summer and 500 l/s in winter is planned from the intake at Hjartsjå.
From the intake at Sønderlandsvatn lake, 360 l/s will be released in summer and 100 l/s in winter. The minimum flow in Skogsåa river cannot be guaranteed during long periods of drought and periods of very low inflow. Release of the minimum flow will be important during dry periods for both Hjartdøla and Skogsåa rivers. The minimum flow at Sauland Power Plant will be higher than before the development, since some of the reservoirs will be used to secure the minimum flow.

The developer will supplement the minimum water release from Hjartsjå, to ensure that a minimum flow from Omnesfossen waterfall of 2,500 l/s in the summer and 1,000 l/s in the winter can be observed.