Usta or Usteåne is a river in Hol, Buskerud County, Norway. It flows from Lake Ustevatn traveling northeast down the valley of Ustedalen to its confluence with Holselva. The ski resort at Geilo is situated just north of the river, about halfway down Ustedalen valley. The valley stretches about 20 km east from Ustevatn and meetings Holsdalføret below Hagafoss.
In 1965 almost all the waters of the Usta was diverted due to the construction of Usta Hydroelectric Power Station. The power station uses the fall in the river Usta of 540 meters from Ustevatn and Rødungen. The power plant is owned and operated by E-CO Energi. The total average annual production at the plant is 780 GWh. Today the lower river is mostly a dry riverbed.[1]