The Deduru Oya is the sixth-longest river of Sri Lanka. It measures approximately in length. It runs across four provinces and five districts. Tributaries Kospothu Oya Dik Oya Ratwila Ela Kimbulwana Oya Hakwatuna Oya Maguru Oya Kolamunu Oya Its catchment area receives approximately 4,313 million cubic metres of rain per year, and approximately 27 percent of the water reaches the sea. It has a catchment area of 2,620 square kilometres. References Bodies of water of Kurunegala District Bodies of water of Puttalam District Rivers of Sri Lanka