The largest lakes within the basin are Åsunden (33,9 km²), Fegen (24,2), Sämsjön (9,2), Lönern (7,7) och Kalven (6,6). In total there is about 200 km² of lakes within the basin. The water flow at Yngeredsfors Power Station has been kept record of. It was on average 37,2 m³/s during the years 1909-1967. The maximum flow was 275 m³/s, while the minimum flow was about 5-7 m³/s.