Udawalawe Reservoir is a reservoir situated on the border of Ratnapura and Monaragala Districts, Sri Lanka. Located bottem of the Udawalawe National Park. This reservoir has been constructed by constructing a long earth wall across the Walawe river. The Udawalawe Dam is a large irrigation dam in Udawalawe, in the Sabaragamuwa Province of Sri Lanka. The dam consists of an embankment section and a gravity section, combining the total dam length to approximately 3.9 km (2.4 mi). The dam is also used for hydroelectric power generation, powering three 2 MW units, commissioned in April 1969.
The water level of the reservoir is controlled by the five tainter gate spillways located at the eastern end of the dam, with two additional spillways located more towards to the center of the dam. The reservoir measures approximately 8.6 km (5.3 mi) in length, with a maximum perpendicular width of 7 km (4.3 mi).
