The Smørholefossen is a regulated waterfall at the end of the Vikadalen near Naddvik/Ardal is a regulated waterfall that (probabaly) only will flow after a long period of heavy rainfall. There are no pictures available for this waterfall that should flow from some small glaciers and the Vasselavatnet/Blåsarbåten over a height of 425 meters. From what I have read the chance to see the fall is almost zero.
Another waterfall nearby, also regulated, is the Skeidslåfossen, also at the end of the Vikadalen. For waterfalls is is better to go to the Utladalen near Øvre Årdal: Avdalsfossen, Vettisfossen, Hjellefossen, Stølsmaradalsfossen and Midtmaradalsfossen. Heaven for waterfall spotters.