Hallingdal River has a total length of  and a catchment area of . The river falls  in its journey to Krøderen, which is  above sea-level. There are many hydro-electric power stations in the valley with an annual power production of about 4 TWh.
Hallingdal River has a total length of  and a drainage area of . The river drops  in its course to Krøderen, which is  above sea level. There are numerous hydroelectric power stations in the valley with an annual energy production of approximately 4 TWh.