In 1980, The National Electricity Authority commenced work on the project of combining several rivulets and small lakes to increase the water supply for its hydroelectric power plants. The project was divided into 5 phases, four of which were finished in 1985. Dams were built to divert water from spilling into River Thjorsa to Lake Thorisvatn. The total area of the new lakes is about 21 km2 and they are connected by ditches. Those lakes have been fished with good results since they were created.