Suldalsvatnet is the sixth-deepest lake in Norway. The 376 m deep lake lies in the municipality of Suldal in Rogaland county, Norway. The 29 km2 lake is the headwaters of the river Suldalslågen and it sits at an elevation of 69 m above sea level. The lake has a volume of 4.51 km3. The 29 km long lake is regulated for use in two nearby hydroelectric power plants.