Victoria Dam is an arch dam located 130 mi (209 km) upstream of the Mahaweli River's mouth and 4 mi (6 km) from Teldeniya. Its main purposes are irrigation and hydroelectric power production. It is the tallest dam in Sri Lanka, and supports a 210 MW power station, the largest hydroelectric power station in the country. Construction of the dam commenced in 1978, and was ceremonially completed by then-President Jayewardene in April 1985.
The dam consists of eight spillways, each with a width and height of 12.5 m (41 ft) and 6.5 m (21.3 ft), which automatically opens when water levels are high. The dam's gates, which needs power only to close, won an award for "Innovative Design in Civil Engineering" by the Institution of Civil Engineers. The total effective width of the spillways is 100 m (328 ft), allowing a maximum discharge of 8,200 m3/s (289,580 cu ft/s). Two additional low-level sluices at the base of the dam allows the purging of accumulated silts behind the dam.