Deduru Oya

The Deduru Oya is the sixth-longest river of Sri Lanka. The 142 km long river runs across four provinces and five districts.

Tributaries

 * Kospothu Oya
 * Dik Oya
 * Ratwila Ela
 * Kimbulwana Oya
 * Hakwatuna Oya
 * Maguru Oya
 * Kolamunu Oya
 * Delvita 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.