Iranamadu Tank, irrigation tank in Kilinochchi District, Northern Province, Sri Lanka

Iranamadu Tank is an irrigation tank on the Kanakarayan Aru about 5 km south east of Kilinochchi, formed by joining two low-lying swamps of the river. Its earthen bund runs roughly 2 km and stands 34 ft (10 m) high, holding back a body of water about 9 km long and 2 km wide. Water reaches the fields through left and right bank sluices and some 32 km of channels.

Proposals for a tank on the Kanakarayan Aru date to 1902, when Director of Irrigation H. T. S. Ward planned a reservoir holding 26 ft of water; work was delayed by World War I and completed in 1921, with labourers housed in a colony that became Kilinochchi. The bund was raised in 1951, 1954 and 1975, reaching 34 ft and a capacity of 106,500 acre-feet. In 1984 deputy director K. Vigneswaran found the bund too weak above 32 ft and capped water levels there.

The name Iranamadu comes from Tamil words meaning 'two ponds', reflecting how two separate water bodies were joined to create it. For the local community, this reservoir has been central to farming life for generations, shaping how people settle and work the land around it.

The bund runs about 2 km along the tank's edge and is the main route for walking; the tank itself is roughly 9 km long. Access is from Kilinochchi, about 5 km to the north west, and the A9 highway passes nearby. Water levels are highest after the north east monsoon rains, when the spill on the left bank comes into use.

The tank was created by joining two naturally separate swamps, an uncommon engineering approach built almost entirely by hand. During droughts in the 1940s, many families relocated nearby because it offered a dependable water source that kept their farming alive.