Ytre Storevatnet is a regulated freshwater lake located in Suldal municipality, Rogaland county, Norway. Situated in the mountainous interior of the county, it is an important component of the Suldalslågen watercourse, which is extensively utilized for hydroelectric power generation.
- Geography: Ytre Storevatnet lies at an elevation that varies significantly due to its regulation as a reservoir, typically between approximately 860 and 900 meters above sea level. It is part of a chain of lakes, often referred to alongside Midtre Storevatnet ("Middle Large Lake") and Indre/Heimra Storevatnet ("Inner/Upper Large Lake"), reflecting their relative positions within the valley system. The surrounding landscape is characterized by high mountains, barren plateaus, and sparse vegetation typical of Norwegian fjellet (mountain plateau) regions.
- Hydrology and Function: The lake serves as a significant water reservoir for the Ulla-Førre hydroelectric power scheme, one of Norway's largest. Water from Ytre Storevatnet, along with other interconnected lakes, is channeled through tunnels to power stations further down the system, eventually draining into the Suldalslågen river and then to the sea.
- Etymology: The name "Ytre Storevatnet" is Norwegian and translates literally to "The Outer Large Lake." "Ytre" means outer or lower, indicating its position relative to other lakes in a sequence, while "Storevatnet" means "the large lake."