Yan Oya (යාන් ඔය)
The Yan Oya is the fifth-longest river of Sri Lanka. It measures approximately 142 km (88 mi) in length. Its catchment area receives approximately 2,371 million cubic metres of rain per year, and approximately 17 percent of the water reaches the sea. It has a catchment area of 1,520 square kilometres.
Yan Oya Project
The work on the Yan Oya irrigation project, the largest irrigation project in the North Central Province has been accelerated, according to the Ministry of Irrigation & Water Resources Management. The Yan Oya reservoir will provide irrigation facilities for agriculture in in Anuradhapura and Trincomalee Districts during both seasons in addition to improving drinking water facilities in the area and providing drinking water and irrigation facilities to Trincomalee town round the clock. The Yan Oya reservoir is constructed by building a dam across Yan Oya, which flows to sea from Pulmoddai in the Eastern Province, at Pangurugaswewa in Trincomalee district. The water capacity of the proposed Yan Oya Reservoir is nearly 140 thousand acre feet. The project at an estimated cost of Rs. 34 billion envisages constructing about 2.35 km long main earthen dam and 3.59 km long saddle dams and 34km long canal system in left Bank (LB) and Right Bank (RB) to irrigate nearly 5,700 hectare of lands in Anuradhapura and Trincomalee Districts. This includes 2200 ha of existing lands under Padaviya scheme where severe water deficit is experienced, especially during Yala season. This will also provide water to 140 ha existing lands under Wahalkada scheme and 100 ha new land along LB canal and existing lands under Yan Oya anicut (750 ha) and minor schemes in Meeoya basin (1735 ha) in Trincomalee District.