The Samanala Dam (Sinhala: සමනලවැව වේල්ල) is a dam primarily used for hydroelectric power generation in Sri Lanka. Commissioned in 1992, the Samanalawewa Project (Samanala Reservoir Project) is the third-largest hydroelectric scheme in the country, producing 405 GWh of energy annually. It was built with financial support from Japan and the United Kingdom. It is notable for a large leak on its right bank. Power production continues as planned despite the leakage, and the water from the leak now provides two thirds of the water issued by the reservoir for agriculture in downstream areas.