Stolsvatnet is a regulated lake in the municipalities of ÃÂ l and Hol in Buskerud, Norway. Stolsvatnet was formed in the late 1940s by the damming of the upper parts of three rivers, (Stolsvatn, Olsendvatn, Holselva) which created a continuous lake across the watersheds. The new lake covered a number of existing smaller lakes. It is a reservoir for Hol I kraftverk, a hydroelectric power plant located off FV 50 by Hovet in Hol. The power plant is owned and operated by E-Co Energi.